From 5b356a3c7c95400ecd188360bafec56e217e2170 Mon Sep 17 00:00:00 2001
From: "Bala.FA" <bala.gluster@gmail.com>
Date: Mon, 15 Jun 2020 21:51:12 +0530
Subject: [PATCH] Add versioning support in listObjects API

---
 .../main/java/io/minio/ListObjectsArgs.java   | 139 ++++--
 api/src/main/java/io/minio/MinioClient.java   | 398 ++++++++++++------
 .../main/java/io/minio/messages/Contents.java |  34 ++
 .../java/io/minio/messages/DeleteMarker.java  |  31 ++
 api/src/main/java/io/minio/messages/Item.java |  51 ++-
 .../io/minio/messages/ListBucketResultV1.java |  21 +-
 .../io/minio/messages/ListBucketResultV2.java |  32 +-
 ...cketResult.java => ListObjectsResult.java} |  67 +--
 .../io/minio/messages/ListVersionsResult.java |  78 ++++
 .../main/java/io/minio/messages/Owner.java    |   4 +-
 .../main/java/io/minio/messages/Prefix.java   |   6 +-
 .../main/java/io/minio/messages/Version.java  |  31 ++
 docs/API.md                                   |  38 +-
 examples/ListObjects.java                     |  74 +++-
 functional/FunctionalTest.java                | 163 +++----
 15 files changed, 829 insertions(+), 338 deletions(-)
 create mode 100644 api/src/main/java/io/minio/messages/Contents.java
 create mode 100644 api/src/main/java/io/minio/messages/DeleteMarker.java
 rename api/src/main/java/io/minio/messages/{ListBucketResult.java => ListObjectsResult.java} (62%)
 create mode 100644 api/src/main/java/io/minio/messages/ListVersionsResult.java
 create mode 100644 api/src/main/java/io/minio/messages/Version.java

diff --git a/api/src/main/java/io/minio/ListObjectsArgs.java b/api/src/main/java/io/minio/ListObjectsArgs.java
index 82ac76c80..951d1ad2e 100644
--- a/api/src/main/java/io/minio/ListObjectsArgs.java
+++ b/api/src/main/java/io/minio/ListObjectsArgs.java
@@ -18,50 +18,77 @@
 
 /** Argument class of @see #listObjects(ListObjectsArgs args). */
 public class ListObjectsArgs extends BucketArgs {
-  private String continuationToken;
-  private String delimiter;
-  private boolean fetchOwner;
-  private Integer maxKeys;
-  private String prefix;
-  private String startAfter;
-  private boolean includeUserMetadata;
+  private String delimiter = "";
+  private boolean useUrlEncodingType = true;
+  private String keyMarker; // 'marker' for ListObjectsV1 and 'startAfter' for ListObjectsV2.
+  private int maxKeys = 1000;
+  private String prefix = "";
+  private String continuationToken; // only for ListObjectsV2.
+  private boolean fetchOwner; // only for ListObjectsV2.
+  private String versionIdMarker; // only for GetObjectVersions.
+  private boolean includeUserMetadata; // MinIO extension applicable to ListObjectsV2.
   private boolean recursive;
-  private boolean useVersion1;
+  private boolean useApiVersion1;
+  private boolean includeVersions;
 
-  public String continuationToken() {
-    return continuationToken;
+  public String delimiter() {
+    if (recursive) {
+      return "";
+    }
+
+    return (delimiter.isEmpty() ? "/" : delimiter);
   }
 
-  public boolean includeUserMetadata() {
-    return includeUserMetadata;
+  public boolean useUrlEncodingType() {
+    return useUrlEncodingType;
+  }
+
+  public String keyMarker() {
+    return keyMarker;
+  }
+
+  public String marker() {
+    return keyMarker;
   }
 
   public String startAfter() {
-    return startAfter;
+    return keyMarker;
+  }
+
+  public int maxKeys() {
+    return maxKeys;
   }
 
   public String prefix() {
     return prefix;
   }
 
-  public Integer maxKeys() {
-    return maxKeys;
+  public String continuationToken() {
+    return continuationToken;
   }
 
   public boolean fetchOwner() {
     return fetchOwner;
   }
 
-  public String delimiter() {
-    return delimiter;
+  public String versionIdMarker() {
+    return versionIdMarker;
+  }
+
+  public boolean includeUserMetadata() {
+    return includeUserMetadata;
   }
 
   public boolean recursive() {
     return recursive;
   }
 
-  public boolean useVersion1() {
-    return useVersion1;
+  public boolean useApiVersion1() {
+    return useApiVersion1;
+  }
+
+  public boolean includeVersions() {
+    return includeVersions;
   }
 
   public static Builder builder() {
@@ -70,28 +97,67 @@ public static Builder builder() {
 
   /** Argument builder of @see MinioClient#listObjects(ListObjectArgs args). */
   public static final class Builder extends BucketArgs.Builder<Builder, ListObjectsArgs> {
-    public Builder continuationToken(String continuationToken) {
-      operations.add(args -> args.continuationToken = continuationToken);
+    @Override
+    protected void validate(ListObjectsArgs args) {
+      super.validate(args);
+
+      if (args.useApiVersion1() || args.includeVersions()) {
+        if (args.continuationToken() != null || args.fetchOwner() || args.includeUserMetadata()) {
+          throw new IllegalArgumentException(
+              "continuation token/fetch owner/include metadata are supported only"
+                  + " for list objects version 2");
+        }
+      }
+
+      if (args.versionIdMarker != null && args.useApiVersion1()) {
+        throw new IllegalArgumentException(
+            "version ID marker is not supported for list objects version 1");
+      }
+    }
+
+    public Builder delimiter(String delimiter) {
+      operations.add(args -> args.delimiter = (delimiter == null ? "" : delimiter));
       return this;
     }
 
-    public Builder includeUserMetadata(boolean includeUserMetadata) {
-      operations.add(args -> args.includeUserMetadata = includeUserMetadata);
+    public Builder useUrlEncodingType(boolean flag) {
+      operations.add(args -> args.useUrlEncodingType = flag);
+      return this;
+    }
+
+    public Builder keyMarker(String keyMarker) {
+      validateNullOrNotEmptyString(keyMarker, "key marker");
+      operations.add(args -> args.keyMarker = keyMarker);
+      return this;
+    }
+
+    public Builder marker(String marker) {
+      operations.add(args -> args.keyMarker = marker);
       return this;
     }
 
     public Builder startAfter(String startAfter) {
-      operations.add(args -> args.startAfter = startAfter);
+      operations.add(args -> args.keyMarker = startAfter);
+      return this;
+    }
+
+    public Builder maxKeys(int maxKeys) {
+      if (maxKeys < 1 || maxKeys > 1000) {
+        throw new IllegalArgumentException("max keys must be between 1 and 1000");
+      }
+
+      operations.add(args -> args.maxKeys = maxKeys);
       return this;
     }
 
     public Builder prefix(String prefix) {
-      operations.add(args -> args.prefix = prefix);
+      operations.add(args -> args.prefix = (prefix == null ? "" : prefix));
       return this;
     }
 
-    public Builder maxKeys(Integer maxKeys) {
-      operations.add(args -> args.maxKeys = maxKeys);
+    public Builder continuationToken(String continuationToken) {
+      validateNullOrNotEmptyString(continuationToken, "continuation token");
+      operations.add(args -> args.continuationToken = continuationToken);
       return this;
     }
 
@@ -100,8 +166,14 @@ public Builder fetchOwner(boolean fetchOwner) {
       return this;
     }
 
-    public Builder delimiter(String delimiter) {
-      operations.add(args -> args.delimiter = delimiter);
+    public Builder versionIdMarker(String versionIdMarker) {
+      validateNullOrNotEmptyString(versionIdMarker, "version ID marker");
+      operations.add(args -> args.versionIdMarker = versionIdMarker);
+      return this;
+    }
+
+    public Builder includeUserMetadata(boolean includeUserMetadata) {
+      operations.add(args -> args.includeUserMetadata = includeUserMetadata);
       return this;
     }
 
@@ -110,8 +182,13 @@ public Builder recursive(boolean recursive) {
       return this;
     }
 
-    public Builder useVersion1(boolean useVersion1) {
-      operations.add(args -> args.useVersion1 = useVersion1);
+    public Builder useApiVersion1(boolean useApiVersion1) {
+      operations.add(args -> args.useApiVersion1 = useApiVersion1);
+      return this;
+    }
+
+    public Builder includeVersions(boolean includeVersions) {
+      operations.add(args -> args.includeVersions = includeVersions);
       return this;
     }
   }
diff --git a/api/src/main/java/io/minio/MinioClient.java b/api/src/main/java/io/minio/MinioClient.java
index f1597f544..964cbbce1 100755
--- a/api/src/main/java/io/minio/MinioClient.java
+++ b/api/src/main/java/io/minio/MinioClient.java
@@ -57,11 +57,12 @@
 import io.minio.messages.Item;
 import io.minio.messages.LegalHold;
 import io.minio.messages.ListAllMyBucketsResult;
-import io.minio.messages.ListBucketResult;
 import io.minio.messages.ListBucketResultV1;
 import io.minio.messages.ListBucketResultV2;
 import io.minio.messages.ListMultipartUploadsResult;
+import io.minio.messages.ListObjectsResult;
 import io.minio.messages.ListPartsResult;
+import io.minio.messages.ListVersionsResult;
 import io.minio.messages.LocationConstraint;
 import io.minio.messages.NotificationConfiguration;
 import io.minio.messages.NotificationRecords;
@@ -3508,7 +3509,7 @@ public Iterable<Result<Item>> listObjects(
       final String prefix,
       final boolean recursive,
       final boolean useVersion1) {
-    return listObjects(bucketName, prefix, recursive, false, false);
+    return listObjects(bucketName, prefix, recursive, false, useVersion1);
   }
 
   /**
@@ -3550,32 +3551,47 @@ public Iterable<Result<Item>> listObjects(
             .prefix(prefix)
             .recursive(recursive)
             .includeUserMetadata(includeUserMetadata)
+            .useApiVersion1(useVersion1)
             .build());
   }
 
   /**
-   * Lists objects information of a bucket. Supports both the versions 1 and 2 of the S3 API. By
-   * default, the <a href="https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectsV2.html">
-   * version 2</a> API is used. <br>
-   * <a href="https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjects.html">version 1</a>
+   * Lists objects information optionally with versions of a bucket. Supports both the versions 1
+   * and 2 of the S3 API. By default, the <a
+   * href="https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectsV2.html">version 2</a> API
+   * is used. <br>
+   * <a href="https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjects.html">Version 1</a>
    * can be used by passing the optional argument {@code useVersion1} as {@code true}.
    *
-   * <pre>Example:
-   * {@code
-   *   Iterable<Result<Item>> results = minioClient.listObjects(
+   * <pre>Example:{@code
+   * // Lists objects information.
+   * Iterable<Result<Item>> results = minioClient.listObjects(
+   *     ListObjectsArgs.builder().bucket("my-bucketname").build());
+   *
+   * // Lists objects information recursively.
+   * Iterable<Result<Item>> results = minioClient.listObjects(
+   *     ListObjectsArgs.builder().bucket("my-bucketname").recursive(true).build());
+   *
+   * // Lists maximum 100 objects information those names starts with 'E' and after
+   * // 'ExampleGuide.pdf'.
+   * Iterable<Result<Item>> results = minioClient.listObjects(
    *     ListObjectsArgs.builder()
-   *       .bucket("my-bucketname")
-   *       .includeUserMetadata(true)
-   *       .startAfter("start-after-entry")
-   *       .prefix("my-obj")
-   *       .maxKeys(100)
-   *       .fetchOwner(true)
-   *   );
-   *   for (Result<Item> result : results) {
-   *     Item item = result.get();
-   *     System.out.println(
-   *       item.lastModified() + ", " + item.size() + ", " + item.objectName());
-   *   }
+   *         .bucket("my-bucketname")
+   *         .startAfter("ExampleGuide.pdf")
+   *         .prefix("E")
+   *         .maxKeys(100)
+   *         .build());
+   *
+   * // Lists maximum 100 objects information with version those names starts with 'E' and after
+   * // 'ExampleGuide.pdf'.
+   * Iterable<Result<Item>> results = minioClient.listObjects(
+   *     ListObjectsArgs.builder()
+   *         .bucket("my-bucketname")
+   *         .startAfter("ExampleGuide.pdf")
+   *         .prefix("E")
+   *         .maxKeys(100)
+   *         .includeVersions(true)
+   *         .build());
    * }</pre>
    *
    * @param args Instance of {@link ListObjectsArgs} built using the builder
@@ -3583,36 +3599,26 @@ public Iterable<Result<Item>> listObjects(
    * @throws XmlParserException upon parsing response xml
    */
   public Iterable<Result<Item>> listObjects(ListObjectsArgs args) {
-    if (args.useVersion1()) {
-      if (args.includeUserMetadata()) {
-        throw new IllegalArgumentException(
-            "include user metadata flag is not supported in version 1");
-      }
+    if (args.includeVersions() || args.versionIdMarker() != null) {
+      return listObjectVersions(args);
+    }
+
+    if (args.useApiVersion1()) {
       return listObjectsV1(args);
-    } else {
-      return listObjectsV2(args);
     }
+
+    return listObjectsV2(args);
   }
 
   private abstract class ObjectIterator implements Iterator<Result<Item>> {
     protected Result<Item> error;
     protected Iterator<Item> itemIterator;
+    protected Iterator<Item> deleteMarkerIterator;
     protected Iterator<Prefix> prefixIterator;
     protected boolean completed = false;
-    protected ListBucketResult listBucketResult;
+    protected ListObjectsResult listObjectsResult;
     protected String lastObjectName;
 
-    protected String getDelimiter(ListObjectsArgs args) {
-      if (args.recursive()) {
-        return null;
-      }
-      String delimiter = args.delimiter();
-      if (delimiter == null) {
-        return "/";
-      }
-      return delimiter;
-    }
-
     protected abstract void populateResult()
         throws ErrorResponseException, IllegalArgumentException, InsufficientDataException,
             InternalException, InvalidBucketNameException, InvalidKeyException,
@@ -3634,14 +3640,16 @@ protected synchronized void populate() {
           | ServerException
           | XmlParserException e) {
         this.error = new Result<>(e);
-      } finally {
-        if (this.listBucketResult != null) {
-          this.itemIterator = this.listBucketResult.contents().iterator();
-          this.prefixIterator = this.listBucketResult.commonPrefixes().iterator();
-        } else {
-          this.itemIterator = new LinkedList<Item>().iterator();
-          this.prefixIterator = new LinkedList<Prefix>().iterator();
-        }
+      }
+
+      if (this.listObjectsResult != null) {
+        this.itemIterator = this.listObjectsResult.contents().iterator();
+        this.deleteMarkerIterator = this.listObjectsResult.deleteMarkers().iterator();
+        this.prefixIterator = this.listObjectsResult.commonPrefixes().iterator();
+      } else {
+        this.itemIterator = new LinkedList<Item>().iterator();
+        this.deleteMarkerIterator = new LinkedList<Item>().iterator();
+        this.prefixIterator = new LinkedList<Prefix>().iterator();
       }
     }
 
@@ -3651,14 +3659,18 @@ public boolean hasNext() {
         return false;
       }
 
-      if (this.error == null && this.itemIterator == null && this.prefixIterator == null) {
+      if (this.error == null
+          && this.itemIterator == null
+          && this.deleteMarkerIterator == null
+          && this.prefixIterator == null) {
         populate();
       }
 
       if (this.error == null
           && !this.itemIterator.hasNext()
+          && !this.deleteMarkerIterator.hasNext()
           && !this.prefixIterator.hasNext()
-          && this.listBucketResult.isTruncated()) {
+          && this.listObjectsResult.isTruncated()) {
         populate();
       }
 
@@ -3670,6 +3682,10 @@ public boolean hasNext() {
         return true;
       }
 
+      if (this.deleteMarkerIterator.hasNext()) {
+        return true;
+      }
+
       if (this.prefixIterator.hasNext()) {
         return true;
       }
@@ -3684,14 +3700,18 @@ public Result<Item> next() {
         throw new NoSuchElementException();
       }
 
-      if (this.error == null && this.itemIterator == null && this.prefixIterator == null) {
+      if (this.error == null
+          && this.itemIterator == null
+          && this.deleteMarkerIterator == null
+          && this.prefixIterator == null) {
         populate();
       }
 
       if (this.error == null
           && !this.itemIterator.hasNext()
+          && !this.deleteMarkerIterator.hasNext()
           && !this.prefixIterator.hasNext()
-          && this.listBucketResult.isTruncated()) {
+          && this.listObjectsResult.isTruncated()) {
         populate();
       }
 
@@ -3705,6 +3725,11 @@ public Result<Item> next() {
         this.lastObjectName = item.objectName();
         return new Result<>(item);
       }
+
+      if (this.deleteMarkerIterator.hasNext()) {
+        return new Result<>(this.deleteMarkerIterator.next());
+      }
+
       if (this.prefixIterator.hasNext()) {
         return new Result<>(this.prefixIterator.next().toItem());
       }
@@ -3724,31 +3749,33 @@ private Iterable<Result<Item>> listObjectsV2(ListObjectsArgs args) {
       @Override
       public Iterator<Result<Item>> iterator() {
         return new ObjectIterator() {
+          private ListBucketResultV2 result = null;
+
+          @Override
           protected void populateResult()
               throws ErrorResponseException, IllegalArgumentException, InsufficientDataException,
                   InternalException, InvalidBucketNameException, InvalidKeyException,
                   InvalidResponseException, IOException, NoSuchAlgorithmException, ServerException,
                   XmlParserException {
-            String delimiter = getDelimiter(args);
-            String continuationToken = null;
-            if (this.listBucketResult != null) {
-              continuationToken = listBucketResult.nextContinuationToken();
-            }
-
-            this.listBucketResult = null;
+            this.listObjectsResult = null;
             this.itemIterator = null;
             this.prefixIterator = null;
 
-            this.listBucketResult =
-                invokeListObjectsV2(
-                    ListObjectsArgs.builder()
-                        .bucket(args.bucket())
-                        .continuationToken(continuationToken)
-                        .delimiter(delimiter)
-                        .fetchOwner(args.fetchOwner())
-                        .prefix(args.prefix())
-                        .includeUserMetadata(args.includeUserMetadata())
-                        .build());
+            result =
+                listObjectsV2(
+                    args.bucket(),
+                    args.region(),
+                    args.delimiter(),
+                    args.useUrlEncodingType(),
+                    args.startAfter(),
+                    args.maxKeys(),
+                    args.prefix(),
+                    (result == null) ? args.continuationToken() : result.nextContinuationToken(),
+                    args.fetchOwner(),
+                    args.includeUserMetadata(),
+                    args.extraHeaders(),
+                    args.extraQueryParams());
+            this.listObjectsResult = result;
           }
         };
       }
@@ -3760,34 +3787,71 @@ private Iterable<Result<Item>> listObjectsV1(ListObjectsArgs args) {
       @Override
       public Iterator<Result<Item>> iterator() {
         return new ObjectIterator() {
+          private ListBucketResultV1 result = null;
+
           @Override
           protected void populateResult()
               throws ErrorResponseException, IllegalArgumentException, InsufficientDataException,
                   InternalException, InvalidBucketNameException, InvalidKeyException,
                   InvalidResponseException, IOException, NoSuchAlgorithmException, ServerException,
                   XmlParserException {
-            String delimiter = getDelimiter(args);
-            String continuationToken = null;
-            if (this.listBucketResult != null) {
-              if (delimiter != null) {
-                continuationToken = listBucketResult.nextContinuationToken();
-              } else {
-                continuationToken = this.lastObjectName;
-              }
+            this.listObjectsResult = null;
+            this.itemIterator = null;
+            this.prefixIterator = null;
+
+            String nextMarker = (result == null) ? args.marker() : result.nextMarker();
+            if (nextMarker == null) {
+              nextMarker = this.lastObjectName;
             }
 
-            this.listBucketResult = null;
+            result =
+                listObjectsV1(
+                    args.bucket(),
+                    args.region(),
+                    args.delimiter(),
+                    args.useUrlEncodingType(),
+                    nextMarker,
+                    args.maxKeys(),
+                    args.prefix(),
+                    args.extraHeaders(),
+                    args.extraQueryParams());
+            this.listObjectsResult = result;
+          }
+        };
+      }
+    };
+  }
+
+  private Iterable<Result<Item>> listObjectVersions(ListObjectsArgs args) {
+    return new Iterable<Result<Item>>() {
+      @Override
+      public Iterator<Result<Item>> iterator() {
+        return new ObjectIterator() {
+          private ListVersionsResult result = null;
+
+          @Override
+          protected void populateResult()
+              throws ErrorResponseException, IllegalArgumentException, InsufficientDataException,
+                  InternalException, InvalidBucketNameException, InvalidKeyException,
+                  InvalidResponseException, IOException, NoSuchAlgorithmException, ServerException,
+                  XmlParserException {
+            this.listObjectsResult = null;
             this.itemIterator = null;
             this.prefixIterator = null;
 
-            this.listBucketResult =
-                invokeListObjectsV1(
-                    ListObjectsArgs.builder()
-                        .bucket(args.bucket())
-                        .delimiter(args.delimiter())
-                        .startAfter(continuationToken)
-                        .prefix(args.prefix())
-                        .build());
+            result =
+                listObjectVersions(
+                    args.bucket(),
+                    args.region(),
+                    args.delimiter(),
+                    args.useUrlEncodingType(),
+                    (result == null) ? args.keyMarker() : result.nextKeyMarker(),
+                    args.maxKeys(),
+                    args.prefix(),
+                    (result == null) ? args.versionIdMarker() : result.nextVersionIdMarker(),
+                    args.extraHeaders(),
+                    args.extraQueryParams());
+            this.listObjectsResult = result;
           }
         };
       }
@@ -7652,72 +7716,144 @@ protected DeleteResult deleteObjects(
     }
   }
 
-  private Map<String, String> getCommonListObjectsQueryParams(ListObjectsArgs args) {
-    Map<String, String> queryParamMap = new HashMap<>();
-
-    if (args.delimiter() != null) {
-      queryParamMap.put("delimiter", args.delimiter());
-    } else {
-      queryParamMap.put("delimiter", "");
-    }
-
-    if (args.maxKeys() != null) {
-      queryParamMap.put("max-keys", args.maxKeys().toString());
-    }
-
-    if (args.prefix() != null) {
-      queryParamMap.put("prefix", args.prefix());
-    } else {
-      queryParamMap.put("prefix", "");
+  private Multimap<String, String> getCommonListObjectsQueryParams(
+      String delimiter, boolean useUrlEncodingType, int maxKeys, String prefix) {
+    Multimap<String, String> queryParams = HashMultimap.create();
+    queryParams.put("delimiter", (delimiter == null) ? "" : delimiter);
+    if (useUrlEncodingType) {
+      queryParams.put("encoding-type", "url");
     }
-
-    return queryParamMap;
+    queryParams.put("max-keys", Integer.toString(maxKeys > 0 ? maxKeys : 1000));
+    queryParams.put("prefix", (prefix == null) ? "" : prefix);
+    return queryParams;
   }
 
-  private ListBucketResultV2 invokeListObjectsV2(ListObjectsArgs args)
+  protected ListBucketResultV2 listObjectsV2(
+      String bucketName,
+      String region,
+      String delimiter,
+      boolean useUrlEncodingType,
+      String startAfter,
+      int maxKeys,
+      String prefix,
+      String continuationToken,
+      boolean fetchOwner,
+      boolean includeUserMetadata,
+      Multimap<String, String> extraHeaders,
+      Multimap<String, String> extraQueryParams)
       throws InvalidKeyException, InvalidBucketNameException, IllegalArgumentException,
           NoSuchAlgorithmException, InsufficientDataException, ServerException, XmlParserException,
           ErrorResponseException, InternalException, InvalidResponseException, IOException {
-    Map<String, String> queryParamMap = getCommonListObjectsQueryParams(args);
-    queryParamMap.put("list-type", "2");
-
-    if (args.continuationToken() != null) {
-      queryParamMap.put("continuation-token", args.continuationToken());
+    Multimap<String, String> queryParams = HashMultimap.create();
+    if (extraQueryParams != null) {
+      queryParams.putAll(extraQueryParams);
     }
-
-    if (args.fetchOwner()) {
-      queryParamMap.put("fetch-owner", "true");
+    queryParams.putAll(
+        getCommonListObjectsQueryParams(delimiter, useUrlEncodingType, maxKeys, prefix));
+    queryParams.put("list-type", "2");
+    if (continuationToken != null) {
+      queryParams.put("continuation-token", continuationToken);
     }
-
-    if (args.startAfter() != null) {
-      queryParamMap.put("start-after", args.startAfter());
+    if (fetchOwner) {
+      queryParams.put("fetch-owner", "true");
     }
-
-    if (args.includeUserMetadata()) {
-      queryParamMap.put("metadata", "true");
+    if (startAfter != null) {
+      queryParams.put("start-after", startAfter);
+    }
+    if (includeUserMetadata) {
+      queryParams.put("metadata", "true");
     }
 
-    Response response = executeGet(args.bucket(), null, null, queryParamMap);
-
-    try (ResponseBody body = response.body()) {
-      return Xml.unmarshal(ListBucketResultV2.class, body.charStream());
+    try (Response response =
+        execute(
+            Method.GET,
+            bucketName,
+            null,
+            (region == null) ? getRegion(bucketName) : region,
+            extraHeaders,
+            queryParams,
+            null,
+            0)) {
+      return Xml.unmarshal(ListBucketResultV2.class, response.body().charStream());
     }
   }
 
-  private ListBucketResultV1 invokeListObjectsV1(ListObjectsArgs args)
+  protected ListBucketResultV1 listObjectsV1(
+      String bucketName,
+      String region,
+      String delimiter,
+      boolean useUrlEncodingType,
+      String marker,
+      int maxKeys,
+      String prefix,
+      Multimap<String, String> extraHeaders,
+      Multimap<String, String> extraQueryParams)
       throws InvalidBucketNameException, IllegalArgumentException, NoSuchAlgorithmException,
           InsufficientDataException, IOException, InvalidKeyException, ServerException,
           XmlParserException, ErrorResponseException, InternalException, InvalidResponseException {
-    Map<String, String> queryParamMap = getCommonListObjectsQueryParams(args);
+    Multimap<String, String> queryParams = HashMultimap.create();
+    if (extraQueryParams != null) {
+      queryParams.putAll(extraQueryParams);
+    }
+    queryParams.putAll(
+        getCommonListObjectsQueryParams(delimiter, useUrlEncodingType, maxKeys, prefix));
+    if (marker != null) {
+      queryParams.put("marker", marker);
+    }
 
-    if (args.startAfter() != null) {
-      queryParamMap.put("marker", args.startAfter());
+    try (Response response =
+        execute(
+            Method.GET,
+            bucketName,
+            null,
+            (region == null) ? getRegion(bucketName) : region,
+            extraHeaders,
+            queryParams,
+            null,
+            0)) {
+      return Xml.unmarshal(ListBucketResultV1.class, response.body().charStream());
     }
+  }
 
-    Response response = executeGet(args.bucket(), null, null, queryParamMap);
+  protected ListVersionsResult listObjectVersions(
+      String bucketName,
+      String region,
+      String delimiter,
+      boolean useUrlEncodingType,
+      String keyMarker,
+      int maxKeys,
+      String prefix,
+      String versionIdMarker,
+      Multimap<String, String> extraHeaders,
+      Multimap<String, String> extraQueryParams)
+      throws InvalidBucketNameException, IllegalArgumentException, NoSuchAlgorithmException,
+          InsufficientDataException, IOException, InvalidKeyException, ServerException,
+          XmlParserException, ErrorResponseException, InternalException, InvalidResponseException {
+    Multimap<String, String> queryParams = HashMultimap.create();
+    if (extraQueryParams != null) {
+      queryParams.putAll(extraQueryParams);
+    }
+    queryParams.putAll(
+        getCommonListObjectsQueryParams(delimiter, useUrlEncodingType, maxKeys, prefix));
+    if (keyMarker != null) {
+      queryParams.put("key-marker", keyMarker);
+    }
+    if (versionIdMarker != null) {
+      queryParams.put("version-id-marker", versionIdMarker);
+    }
+    queryParams.put("versions", "");
 
-    try (ResponseBody body = response.body()) {
-      return Xml.unmarshal(ListBucketResultV1.class, body.charStream());
+    try (Response response =
+        execute(
+            Method.GET,
+            bucketName,
+            null,
+            (region == null) ? getRegion(bucketName) : region,
+            extraHeaders,
+            queryParams,
+            null,
+            0)) {
+      return Xml.unmarshal(ListVersionsResult.class, response.body().charStream());
     }
   }
 
diff --git a/api/src/main/java/io/minio/messages/Contents.java b/api/src/main/java/io/minio/messages/Contents.java
new file mode 100644
index 000000000..873e800e7
--- /dev/null
+++ b/api/src/main/java/io/minio/messages/Contents.java
@@ -0,0 +1,34 @@
+/*
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.minio.messages;
+
+import org.simpleframework.xml.Root;
+
+/**
+ * Helper class to denote Object information in {@link ListBucketResultV1} and {@link
+ * ListBucketResultV2}
+ */
+@Root(name = "Contents", strict = false)
+public class Contents extends Item {
+  public Contents() {
+    super();
+  }
+
+  public Contents(String prefix) {
+    super(prefix);
+  }
+}
diff --git a/api/src/main/java/io/minio/messages/DeleteMarker.java b/api/src/main/java/io/minio/messages/DeleteMarker.java
new file mode 100644
index 000000000..0e95b74ed
--- /dev/null
+++ b/api/src/main/java/io/minio/messages/DeleteMarker.java
@@ -0,0 +1,31 @@
+/*
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.minio.messages;
+
+import org.simpleframework.xml.Root;
+
+/** Helper class to denote delete marker information in {@link ListVersionsResult}. */
+@Root(name = "DeleteMarker", strict = false)
+public class DeleteMarker extends Item {
+  public DeleteMarker() {
+    super();
+  }
+
+  public DeleteMarker(String prefix) {
+    super(prefix);
+  }
+}
diff --git a/api/src/main/java/io/minio/messages/Item.java b/api/src/main/java/io/minio/messages/Item.java
index edff21c92..79b3c0052 100644
--- a/api/src/main/java/io/minio/messages/Item.java
+++ b/api/src/main/java/io/minio/messages/Item.java
@@ -19,31 +19,35 @@
 import java.time.ZonedDateTime;
 import java.util.Map;
 import org.simpleframework.xml.Element;
-import org.simpleframework.xml.Root;
 
 /**
- * Helper class to denote Object information in {@link ListBucketResult} and {@link
- * ListBucketResultV1}.
+ * Helper class to denote Object information in {@link ListBucketResultV1}, {@link
+ * ListBucketResultV2} and {@link ListVersionsResult}.
  */
-@Root(name = "Contents", strict = false)
-public class Item {
+public abstract class Item {
+  @Element(name = "ETag", required = false)
+  private String etag; // except DeleteMarker
+
   @Element(name = "Key")
   private String objectName;
 
   @Element(name = "LastModified")
   private ResponseDate lastModified;
 
-  @Element(name = "ETag")
-  private String etag;
+  @Element(name = "Owner", required = false)
+  private Owner owner;
+
+  @Element(name = "Size", required = false)
+  private long size; // except DeleteMarker
 
-  @Element(name = "Size")
-  private long size;
+  @Element(name = "StorageClass", required = false)
+  private String storageClass; // except DeleteMarker
 
-  @Element(name = "StorageClass")
-  private String storageClass;
+  @Element(name = "IsLatest", required = false)
+  private boolean isLatest; // except ListObjects V1
 
-  @Element(name = "Owner", required = false)
-  private Owner owner;
+  @Element(name = "VersionId", required = false)
+  private String versionId; // except ListObjects V1
 
   @Element(name = "UserMetadata", required = false)
   private Metadata userMetadata;
@@ -90,15 +94,26 @@ public Owner owner() {
 
   /** Returns user metadata. This is MinIO specific extension to ListObjectsV2. */
   public Map<String, String> userMetadata() {
-    if (userMetadata == null) {
-      return null;
-    }
+    return (userMetadata == null) ? null : userMetadata.get();
+  }
+
+  /** Returns whether this version ID is latest. */
+  public boolean isLatest() {
+    return isLatest;
+  }
 
-    return userMetadata.get();
+  /** Returns version ID. */
+  public String versionId() {
+    return versionId;
   }
 
-  /** Returns whether the object is a directory or not. */
+  /** Returns whether this item is a directory or not. */
   public boolean isDir() {
     return isDir;
   }
+
+  /** Returns whether this item is a delete marker or not. */
+  public boolean isDeleteMarker() {
+    return (etag == null && size == 0 && storageClass == null && versionId != null);
+  }
 }
diff --git a/api/src/main/java/io/minio/messages/ListBucketResultV1.java b/api/src/main/java/io/minio/messages/ListBucketResultV1.java
index d1f8ec702..0d4260013 100644
--- a/api/src/main/java/io/minio/messages/ListBucketResultV1.java
+++ b/api/src/main/java/io/minio/messages/ListBucketResultV1.java
@@ -16,7 +16,11 @@
 
 package io.minio.messages;
 
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import org.simpleframework.xml.Element;
+import org.simpleframework.xml.ElementList;
 import org.simpleframework.xml.Namespace;
 import org.simpleframework.xml.Root;
 
@@ -26,22 +30,25 @@
  */
 @Root(name = "ListBucketResult", strict = false)
 @Namespace(reference = "http://s3.amazonaws.com/doc/2006-03-01/")
-public class ListBucketResultV1 extends ListBucketResult {
+public class ListBucketResultV1 extends ListObjectsResult {
   @Element(name = "Marker", required = false)
   private String marker;
 
   @Element(name = "NextMarker", required = false)
   private String nextMarker;
 
-  /** Returns continuation token. */
-  @Override
-  public String continuationToken() {
+  @ElementList(name = "Contents", inline = true, required = false)
+  private List<Contents> contents;
+
+  public String marker() {
     return marker;
   }
 
-  /** Returns next continuation token. */
-  @Override
-  public String nextContinuationToken() {
+  public String nextMarker() {
     return nextMarker;
   }
+
+  public List<Item> contents() {
+    return Collections.unmodifiableList((contents == null) ? new LinkedList<>() : contents);
+  }
 }
diff --git a/api/src/main/java/io/minio/messages/ListBucketResultV2.java b/api/src/main/java/io/minio/messages/ListBucketResultV2.java
index 34541a430..1742853c0 100644
--- a/api/src/main/java/io/minio/messages/ListBucketResultV2.java
+++ b/api/src/main/java/io/minio/messages/ListBucketResultV2.java
@@ -16,7 +16,11 @@
 
 package io.minio.messages;
 
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
 import org.simpleframework.xml.Element;
+import org.simpleframework.xml.ElementList;
 import org.simpleframework.xml.Namespace;
 import org.simpleframework.xml.Root;
 
@@ -27,22 +31,44 @@
  */
 @Root(name = "ListBucketResult", strict = false)
 @Namespace(reference = "http://s3.amazonaws.com/doc/2006-03-01/")
-public class ListBucketResultV2 extends ListBucketResult {
+public class ListBucketResultV2 extends ListObjectsResult {
+  @Element(name = "KeyCount", required = false)
+  private int keyCount;
+
+  @Element(name = "StartAfter", required = false)
+  private String startAfter;
+
   @Element(name = "ContinuationToken", required = false)
   private String continuationToken;
 
   @Element(name = "NextContinuationToken", required = false)
   private String nextContinuationToken;
 
+  @ElementList(name = "Contents", inline = true, required = false)
+  private List<Contents> contents;
+
+  /** Returns key count. */
+  public int keyCount() {
+    return keyCount;
+  }
+
+  /** Returns start after. */
+  public String startAfter() {
+    return startAfter;
+  }
+
   /** Returns continuation token. */
-  @Override
   public String continuationToken() {
     return continuationToken;
   }
 
   /** Returns next continuation token. */
-  @Override
   public String nextContinuationToken() {
     return nextContinuationToken;
   }
+
+  /** Returns List of Items. */
+  public List<Item> contents() {
+    return Collections.unmodifiableList((contents == null) ? new LinkedList<>() : contents);
+  }
 }
diff --git a/api/src/main/java/io/minio/messages/ListBucketResult.java b/api/src/main/java/io/minio/messages/ListObjectsResult.java
similarity index 62%
rename from api/src/main/java/io/minio/messages/ListBucketResult.java
rename to api/src/main/java/io/minio/messages/ListObjectsResult.java
index c0527d933..b031cbfca 100644
--- a/api/src/main/java/io/minio/messages/ListBucketResult.java
+++ b/api/src/main/java/io/minio/messages/ListObjectsResult.java
@@ -1,5 +1,5 @@
 /*
- * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2015, 2016, 2017 MinIO, Inc.
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,61 +22,46 @@
 import org.simpleframework.xml.Element;
 import org.simpleframework.xml.ElementList;
 
-public abstract class ListBucketResult {
+public abstract class ListObjectsResult {
   @Element(name = "Name")
   private String name;
 
+  @Element(name = "EncodingType", required = false)
+  private String encodingType;
+
   @Element(name = "Prefix", required = false)
   private String prefix;
 
-  @Element(name = "StartAfter", required = false)
-  private String startAfter;
-
-  @Element(name = "KeyCount", required = false)
-  private int keyCount;
-
-  @Element(name = "MaxKeys")
-  private int maxKeys;
-
   @Element(name = "Delimiter", required = false)
   private String delimiter;
 
   @Element(name = "IsTruncated", required = false)
   private boolean isTruncated;
 
-  @ElementList(name = "Contents", inline = true, required = false)
-  private List<Item> contents;
+  @Element(name = "MaxKeys", required = false)
+  private int maxKeys;
 
   @ElementList(name = "CommonPrefixes", inline = true, required = false)
   private List<Prefix> commonPrefixes;
 
-  public ListBucketResult() {}
+  private static final List<Item> deleteMarkers = Collections.unmodifiableList(new LinkedList<>());
+
+  public ListObjectsResult() {}
 
   /** Returns bucket name. */
   public String name() {
     return name;
   }
 
+  public boolean useUrlEncodingType() {
+    return (encodingType != null && encodingType.equals("url"));
+  }
+
   /** Returns prefix. */
   public String prefix() {
     return prefix;
   }
 
-  /** Returns start after. */
-  public String startAfter() {
-    return startAfter;
-  }
-
-  /** Returns key count. */
-  public int keyCount() {
-    return keyCount;
-  }
-
-  /** Returns max keys. */
-  public int maxKeys() {
-    return maxKeys;
-  }
-
   /** Returns delimiter. */
   public String delimiter() {
     return delimiter;
@@ -87,26 +72,20 @@ public boolean isTruncated() {
     return isTruncated;
   }
 
-  /** Returns List of Items. */
-  public List<Item> contents() {
-    if (contents == null) {
-      return Collections.unmodifiableList(new LinkedList<>());
-    }
-
-    return Collections.unmodifiableList(contents);
+  /** Returns max keys. */
+  public int maxKeys() {
+    return maxKeys;
   }
 
   /** Returns List of Prefix. */
   public List<Prefix> commonPrefixes() {
-    if (commonPrefixes == null) {
-      return Collections.unmodifiableList(new LinkedList<>());
-    }
-
-    return Collections.unmodifiableList(commonPrefixes);
+    return Collections.unmodifiableList(
+        (commonPrefixes == null) ? new LinkedList<>() : commonPrefixes);
   }
 
-  /** Returns continuation token. */
-  public abstract String continuationToken();
+  public List<Item> deleteMarkers() {
+    return deleteMarkers;
+  }
 
-  public abstract String nextContinuationToken();
+  public abstract List<Item> contents();
 }
diff --git a/api/src/main/java/io/minio/messages/ListVersionsResult.java b/api/src/main/java/io/minio/messages/ListVersionsResult.java
new file mode 100644
index 000000000..91d854b0a
--- /dev/null
+++ b/api/src/main/java/io/minio/messages/ListVersionsResult.java
@@ -0,0 +1,78 @@
+/*
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.minio.messages;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+import org.simpleframework.xml.Element;
+import org.simpleframework.xml.ElementList;
+import org.simpleframework.xml.Namespace;
+import org.simpleframework.xml.Root;
+
+/**
+ * Object representation of response XML of <a
+ * href="https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectVersions.html">ListObjectVersions
+ * API</a>.
+ */
+@Root(name = "ListVersionsResult", strict = false)
+@Namespace(reference = "http://s3.amazonaws.com/doc/2006-03-01/")
+public class ListVersionsResult extends ListObjectsResult {
+  @Element(name = "KeyMarker", required = false)
+  private String keyMarker;
+
+  @Element(name = "NextKeyMarker", required = false)
+  private String nextKeyMarker;
+
+  @Element(name = "VersionIdMarker", required = false)
+  private String versionIdMarker;
+
+  @Element(name = "NextVersionIdMarker", required = false)
+  private String nextVersionIdMarker;
+
+  @ElementList(name = "Version", inline = true, required = false)
+  private List<Version> contents;
+
+  @ElementList(name = "DeleteMarker", inline = true, required = false)
+  private List<DeleteMarker> deleteMarkers;
+
+  public String keyMarker() {
+    return keyMarker;
+  }
+
+  public String nextKeyMarker() {
+    return nextKeyMarker;
+  }
+
+  public String versionIdMarker() {
+    return versionIdMarker;
+  }
+
+  public String nextVersionIdMarker() {
+    return nextVersionIdMarker;
+  }
+
+  public List<Item> contents() {
+    return Collections.unmodifiableList((contents == null) ? new LinkedList<>() : contents);
+  }
+
+  @Override
+  public List<Item> deleteMarkers() {
+    return Collections.unmodifiableList(
+        (deleteMarkers == null) ? new LinkedList<>() : deleteMarkers);
+  }
+}
diff --git a/api/src/main/java/io/minio/messages/Owner.java b/api/src/main/java/io/minio/messages/Owner.java
index a10d123b7..28ffa998b 100644
--- a/api/src/main/java/io/minio/messages/Owner.java
+++ b/api/src/main/java/io/minio/messages/Owner.java
@@ -21,8 +21,8 @@
 
 /**
  * Helper class to denote owner information for {@link ListAllMyBucketsResult}, {@link
- * ListBucketResult}, {@link ListBucketResultV1}, {@link ListMultipartUploadsResult} and {@link
- * ListPartsResult}.
+ * ListBucketResultV1}, {@link ListBucketResultV2}, {@link ListVersionsResult}, {@link
+ * ListMultipartUploadsResult} and {@link ListPartsResult}.
  */
 @Root(name = "Owner", strict = false)
 public class Owner {
diff --git a/api/src/main/java/io/minio/messages/Prefix.java b/api/src/main/java/io/minio/messages/Prefix.java
index bc2f4343f..4a27a7bc4 100644
--- a/api/src/main/java/io/minio/messages/Prefix.java
+++ b/api/src/main/java/io/minio/messages/Prefix.java
@@ -20,8 +20,8 @@
 import org.simpleframework.xml.Root;
 
 /**
- * Helper class to denote Prefix information in {@link ListBucketResult} and {@link
- * ListBucketResultV1}.
+ * Helper class to denote Prefix information in {@link ListBucketResultV1}, {@link
+ * ListBucketResultV2} and {@link ListVersionsResult}.
  */
 @Root(name = "CommonPrefixes", strict = false)
 public class Prefix {
@@ -31,6 +31,6 @@ public class Prefix {
   public Prefix() {}
 
   public Item toItem() {
-    return new Item(prefix);
+    return new Contents(prefix);
   }
 }
diff --git a/api/src/main/java/io/minio/messages/Version.java b/api/src/main/java/io/minio/messages/Version.java
new file mode 100644
index 000000000..65eb57d97
--- /dev/null
+++ b/api/src/main/java/io/minio/messages/Version.java
@@ -0,0 +1,31 @@
+/*
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.minio.messages;
+
+import org.simpleframework.xml.Root;
+
+/** Helper class to denote object and it's version information in {@link ListVersionsResult}. */
+@Root(name = "Version", strict = false)
+public class Version extends Item {
+  public Version() {
+    super();
+  }
+
+  public Version(String prefix) {
+    super(prefix);
+  }
+}
diff --git a/docs/API.md b/docs/API.md
index 698e9ef04..a61d0ffae 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -727,19 +727,33 @@ __Parameters__
 
 __Example__
 ```java
+// Lists objects information.
 Iterable<Result<Item>> results = minioClient.listObjects(
-  ListObjectsArgs.builder()
-    .bucket("my-bucketname")
-    .includeUserMetadata(true)
-    .startAfter("start-after-entry")
-    .prefix("my-obj")
-    .maxKeys(100)
-    .fetchOwner(true)
-);
-for (Result<Item> result : results) {
-  Item item = result.get();
-  System.out.println(item.lastModified() + ", " + item.size() + ", " + item.objectName());
-}
+    ListObjectsArgs.builder().bucket("my-bucketname").build());
+
+// Lists objects information recursively.
+Iterable<Result<Item>> results = minioClient.listObjects(
+    ListObjectsArgs.builder().bucket("my-bucketname").recursive(true).build());
+
+// Lists maximum 100 objects information those names starts with 'E' and after 'ExampleGuide.pdf'.
+Iterable<Result<Item>> results = minioClient.listObjects(
+    ListObjectsArgs.builder()
+        .bucket("my-bucketname")
+        .startAfter("ExampleGuide.pdf")
+        .prefix("E")
+        .maxKeys(100)
+        .build());
+
+// Lists maximum 100 objects information with version those names starts with 'E' and after
+// 'ExampleGuide.pdf'.
+Iterable<Result<Item>> results = minioClient.listObjects(
+    ListObjectsArgs.builder()
+        .bucket("my-bucketname")
+        .startAfter("ExampleGuide.pdf")
+        .prefix("E")
+        .maxKeys(100)
+        .includeVersions(true)
+        .build());
 ```
 
 ### makeBucket(MakeBucketArgs args)
diff --git a/examples/ListObjects.java b/examples/ListObjects.java
index 208237a82..7ee6443fc 100644
--- a/examples/ListObjects.java
+++ b/examples/ListObjects.java
@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import io.minio.BucketExistsArgs;
 import io.minio.ListObjectsArgs;
 import io.minio.MinioClient;
 import io.minio.Result;
@@ -40,19 +39,72 @@ public static void main(String[] args)
       // MinioClient minioClient = new MinioClient("https://s3.amazonaws.com", "YOUR-ACCESSKEYID",
       //                                           "YOUR-SECRETACCESSKEY");
 
-      // Check whether 'my-bucketname' exist or not.
-      boolean found =
-          minioClient.bucketExists(BucketExistsArgs.builder().bucket("my-bucketname").build());
-      if (found) {
-        // List objects from 'my-bucketname'
-        Iterable<Result<Item>> myObjects =
+      {
+        // Lists objects information.
+        Iterable<Result<Item>> results =
             minioClient.listObjects(ListObjectsArgs.builder().bucket("my-bucketname").build());
-        for (Result<Item> result : myObjects) {
+
+        for (Result<Item> result : results) {
+          Item item = result.get();
+          System.out.println(item.lastModified() + "\t" + item.size() + "\t" + item.objectName());
+        }
+      }
+
+      {
+        // Lists objects information recursively.
+        Iterable<Result<Item>> results =
+            minioClient.listObjects(
+                ListObjectsArgs.builder().bucket("my-bucketname").recursive(true).build());
+
+        for (Result<Item> result : results) {
+          Item item = result.get();
+          System.out.println(item.lastModified() + "\t" + item.size() + "\t" + item.objectName());
+        }
+      }
+
+      {
+        // Lists maximum 100 objects information those names starts with 'E' and after
+        // 'ExampleGuide.pdf'.
+        Iterable<Result<Item>> results =
+            minioClient.listObjects(
+                ListObjectsArgs.builder()
+                    .bucket("my-bucketname")
+                    .startAfter("ExampleGuide.pdf")
+                    .prefix("E")
+                    .maxKeys(100)
+                    .build());
+
+        for (Result<Item> result : results) {
+          Item item = result.get();
+          System.out.println(item.lastModified() + "\t" + item.size() + "\t" + item.objectName());
+        }
+      }
+
+      {
+        // Lists maximum 100 objects information with version those names starts with 'E' and after
+        // 'ExampleGuide.pdf'.
+        Iterable<Result<Item>> results =
+            minioClient.listObjects(
+                ListObjectsArgs.builder()
+                    .bucket("my-bucketname")
+                    .startAfter("ExampleGuide.pdf")
+                    .prefix("E")
+                    .maxKeys(100)
+                    .includeVersions(true)
+                    .build());
+
+        for (Result<Item> result : results) {
           Item item = result.get();
-          System.out.println(item.lastModified() + ", " + item.size() + ", " + item.objectName());
+          System.out.println(
+              item.lastModified()
+                  + "\t"
+                  + item.size()
+                  + "\t"
+                  + item.objectName()
+                  + " ["
+                  + item.versionId()
+                  + "]");
         }
-      } else {
-        System.out.println("my-bucketname does not exist");
       }
     } catch (MinioException e) {
       System.out.println("Error occurred: " + e);
diff --git a/functional/FunctionalTest.java b/functional/FunctionalTest.java
index 4693e48d6..010d307cf 100644
--- a/functional/FunctionalTest.java
+++ b/functional/FunctionalTest.java
@@ -56,6 +56,7 @@
 import io.minio.MakeBucketArgs;
 import io.minio.MinioClient;
 import io.minio.ObjectStat;
+import io.minio.ObjectWriteResponse;
 import io.minio.PostPolicy;
 import io.minio.PutObjectArgs;
 import io.minio.RemoveBucketArgs;
@@ -1356,25 +1357,37 @@ public static void downloadObject_test() throws Exception {
             .build());
   }
 
-  public static String[] createObjects(String bucketName, int count) throws Exception {
-    String[] objectNames = new String[count];
+  public static List<ObjectWriteResponse> createObjects(String bucketName, int count, int versions)
+      throws Exception {
+    List<ObjectWriteResponse> results = new LinkedList<>();
     for (int i = 0; i < count; i++) {
-      objectNames[i] = getRandomName();
-      client.putObject(
-          PutObjectArgs.builder().bucket(bucketName).object(objectNames[i]).stream(
-                  new ContentInputStream(1), 1, -1)
-              .build());
+      String objectName = getRandomName();
+      results.add(
+          client.putObject(
+              PutObjectArgs.builder().bucket(bucketName).object(objectName).stream(
+                      new ContentInputStream(1), 1, -1)
+                  .build()));
+      if (versions > 1) {
+        for (int j = 0; j < versions - 1; j++) {
+          results.add(
+              client.putObject(
+                  PutObjectArgs.builder().bucket(bucketName).object(objectName).stream(
+                          new ContentInputStream(1), 1, -1)
+                      .build()));
+        }
+      }
     }
 
-    return objectNames;
+    return results;
   }
 
-  public static void removeObjects(String bucketName, String[] objectNames) throws Exception {
+  public static void removeObjects(String bucketName, List<ObjectWriteResponse> results)
+      throws Exception {
     List<DeleteObject> objects =
-        Arrays.stream(objectNames)
+        results.stream()
             .map(
-                name -> {
-                  return new DeleteObject(name);
+                result -> {
+                  return new DeleteObject(result.object(), result.versionId());
                 })
             .collect(Collectors.toList());
     for (Result<?> r :
@@ -1385,18 +1398,19 @@ public static void removeObjects(String bucketName, String[] objectNames) throws
   }
 
   public static void testListObjects(
-      String methodName, String tag, ListObjectsArgs args, int objCount) throws Exception {
-    if (!mintEnv) {
-      System.out.println("Test: " + tag + " " + methodName);
-    }
-
+      String testTags, ListObjectsArgs args, int objCount, int versions) throws Exception {
+    String methodName = "listObjects()";
     long startTime = System.currentTimeMillis();
     String bucketName = args.bucket();
-    String[] objectNames = null;
+    List<ObjectWriteResponse> results = null;
     try {
       client.makeBucket(MakeBucketArgs.builder().bucket(bucketName).build());
       try {
-        objectNames = createObjects(bucketName, objCount);
+        if (versions > 0) {
+          client.enableVersioning(EnableVersioningArgs.builder().bucket(bucketName).build());
+        }
+
+        results = createObjects(bucketName, objCount, versions);
 
         int i = 0;
         for (Result<?> r : client.listObjects(args)) {
@@ -1404,74 +1418,69 @@ public static void testListObjects(
           i++;
         }
 
+        if (versions > 0) {
+          objCount *= versions;
+        }
+
         if (i != objCount) {
           throw new Exception("object count; expected=" + objCount + ", got=" + i);
         }
 
-        mintSuccessLog(methodName, tag, startTime);
+        mintSuccessLog(methodName, testTags, startTime);
       } finally {
-        if (objectNames != null) {
-          removeObjects(bucketName, objectNames);
+        if (results != null) {
+          removeObjects(bucketName, results);
         }
         client.removeBucket(RemoveBucketArgs.builder().bucket(bucketName).build());
       }
     } catch (Exception e) {
-      handleException(methodName, tag, startTime, e);
+      handleException(methodName, testTags, startTime, e);
     }
   }
 
-  /** Test: [bucket] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test1() throws Exception {
-    testListObjects(
-        "listObjects(ListObjectsArgs args)",
-        "[bucket]",
-        ListObjectsArgs.builder().bucket(getRandomName()).build(),
-        3);
-  }
+  public static void listObjects_test() throws Exception {
+    if (!mintEnv) {
+      System.out.println("Test: listObjects()");
+    }
+
+    testListObjects("[bucket]", ListObjectsArgs.builder().bucket(getRandomName()).build(), 3, 0);
 
-  /** Test: [bucket, prefix] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test2() throws Exception {
     testListObjects(
-        "listObjects(ListObjectsArgs args)",
         "[bucket, prefix]",
         ListObjectsArgs.builder().bucket(getRandomName()).prefix("minio").build(),
-        3);
-  }
+        3,
+        0);
 
-  /** Test: [bucket, prefix, recursive] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test3() throws Exception {
     testListObjects(
-        "listObjects(ListObjectsArgs args)",
         "[bucket, prefix, recursive]",
         ListObjectsArgs.builder().bucket(getRandomName()).prefix("minio").recursive(true).build(),
-        3);
-  }
+        3,
+        0);
 
-  /** Test: [empty bucket] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test4() throws Exception {
     testListObjects(
-        "listObjects(ListObjectsArgs args)",
-        "[empty bucket]",
-        ListObjectsArgs.builder().bucket(getRandomName()).build(),
-        0);
-  }
+        "[bucket, versions]",
+        ListObjectsArgs.builder().bucket(getRandomName()).includeVersions(true).build(),
+        3,
+        2);
+
+    if (isQuickTest) {
+      return;
+    }
+
+    testListObjects(
+        "[empty bucket]", ListObjectsArgs.builder().bucket(getRandomName()).build(), 0, 0);
 
-  /** Test: [bucket, prefix, recursive, 1050 objects] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test5() throws Exception {
     testListObjects(
-        "listObjects(ListObjectsArgs args)",
         "[bucket, prefix, recursive, 1050 objects]",
         ListObjectsArgs.builder().bucket(getRandomName()).prefix("minio").recursive(true).build(),
-        1050);
-  }
+        1050,
+        0);
 
-  /** Test: [bucket, version1] listObjects(ListObjectsArgs args). */
-  public static void listObjects_test6() throws Exception {
     testListObjects(
-        "listObjects(ListObjectsArgs args)",
-        "[bucket, version1]",
-        ListObjectsArgs.builder().bucket(getRandomName()).useVersion1(true).build(),
-        3);
+        "[bucket, apiVersion1]",
+        ListObjectsArgs.builder().bucket(getRandomName()).useApiVersion1(true).build(),
+        3,
+        0);
   }
 
   /** Test: removeObject(String bucketName, String objectName). */
@@ -1511,18 +1520,17 @@ public static void removeObjects_test1() throws Exception {
     long startTime = System.currentTimeMillis();
     try {
       String bucketName = getRandomName();
-      String[] objectNames = null;
       client.makeBucket(MakeBucketArgs.builder().bucket(bucketName).build());
+      List<ObjectWriteResponse> results = null;
       try {
-        String[] createdNames = createObjects(bucketName, 3);
-        objectNames = new String[createdNames.length + 1];
-        System.arraycopy(createdNames, 0, objectNames, 0, createdNames.length);
-        objectNames[3] = "nonexistent-object";
-        removeObjects(bucketName, objectNames);
+        results = createObjects(bucketName, 3, 0);
+        results.add(
+            new ObjectWriteResponse(null, bucketName, null, "nonexistent-object", null, null));
+        removeObjects(bucketName, results);
         mintSuccessLog(methodName, null, startTime);
       } finally {
-        if (objectNames != null) {
-          removeObjects(bucketName, objectNames);
+        if (results != null) {
+          removeObjects(bucketName, results);
         }
         client.removeBucket(RemoveBucketArgs.builder().bucket(bucketName).build());
       }
@@ -3019,7 +3027,11 @@ public static void setObjectRetention_test1() throws Exception {
 
       } finally {
         client.removeObject(
-            RemoveObjectArgs.builder().bucket(bucketName).object(objectName).build());
+            RemoveObjectArgs.builder()
+                .bucket(bucketName)
+                .object(objectName)
+                .bypassGovernanceMode(true)
+                .build());
         client.removeBucket(RemoveBucketArgs.builder().bucket(bucketName).build());
       }
       mintSuccessLog(methodName, null, startTime);
@@ -3124,7 +3136,11 @@ public static void getObjectRetention_test1() throws Exception {
 
       } finally {
         client.removeObject(
-            RemoveObjectArgs.builder().bucket(bucketName).object(objectName).build());
+            RemoveObjectArgs.builder()
+                .bucket(bucketName)
+                .object(objectName)
+                .bypassGovernanceMode(true)
+                .build());
         client.removeBucket(RemoveBucketArgs.builder().bucket(bucketName).build());
       }
       mintSuccessLog(methodName, null, startTime);
@@ -3915,12 +3931,7 @@ public static void runTests() throws Exception {
     getPresignedObjectUrl_test5();
     getPresignedObjectUrl_test6();
 
-    listObjects_test1();
-    listObjects_test2();
-    listObjects_test3();
-    listObjects_test4();
-    listObjects_test5();
-    listObjects_test6();
+    listObjects_test();
 
     removeObject_test1();
     removeObjects_test1();
@@ -4011,7 +4022,7 @@ public static void runQuickTests() throws Exception {
     statObject_test1();
     getObject_test();
     downloadObject_test();
-    listObjects_test1();
+    listObjects_test();
     removeObject_test1();
     listIncompleteUploads_test1();
     removeIncompleteUploads_test();