Support serialization of Iterator and Stream

src/main/java/com/fasterxml/jackson/dataformat/xml/util/TypeUtil.java

@@ -1,9 +1,11 @@
 package com.fasterxml.jackson.dataformat.xml.util;
 
-import java.util.Collection;
-
 import com.fasterxml.jackson.databind.JavaType;
 
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.stream.Stream;
+
 public class TypeUtil
 {
     /**
@@ -12,8 +14,11 @@ public class TypeUtil
      */
     public static boolean isIndexedType(JavaType type)
     {
-        if (type.isContainerType()) {
-            Class<?> cls = type.getRawClass();
+        Class<?> cls = type.getRawClass();
+        if (type.isContainerType()
+            || Iterator.class.isAssignableFrom(cls)
+            || Stream.class.isAssignableFrom(cls)
+        ) {
             // One special case; byte[] will be serialized as base64-encoded String, not real array, so:
             // (actually, ditto for char[]; thought to be a String)
             if (cls == byte[].class || cls == char[].class) {
@@ -31,7 +36,8 @@ public static boolean isIndexedType(JavaType type)
 
     public static boolean isIndexedType(Class<?> cls)
     {
-        return (cls.isArray() && cls != byte[].class && cls != char[].class)
-                || Collection.class.isAssignableFrom(cls);
+        return  (cls.isArray() && cls != byte[].class && cls != char[].class) 
+            || Collection.class.isAssignableFrom(cls) || Iterator.class.isAssignableFrom(cls)
+            || Stream.class.isAssignableFrom(cls);
     }
 }

src/test/java/com/fasterxml/jackson/dataformat/xml/lists/ListSerializationTest.java

@@ -110,7 +110,7 @@ public void testStringList() throws IOException
     // [dataformat-xml#148]
     public void testIteratorSerialization() throws Exception
     {
-        assertEquals("<Bean148><item>2</item><item>1</item><item>0</item></Bean148>",
+        assertEquals("<Bean148><list><item>2</item><item>1</item><item>0</item></list></Bean148>",
                 MAPPER.writeValueAsString(new Bean148()).trim());
     }
 }

src/test/java/com/fasterxml/jackson/dataformat/xml/ser/Jdk8StreamSerialization302Test.java

@@ -0,0 +1,151 @@
+package com.fasterxml.jackson.dataformat.xml.ser;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
+import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Stream;
+
+// [dataformat-xml#302] : Unable to serialize top-level Java8 Stream
+public class Jdk8StreamSerialization302Test extends XmlTestBase {
+
+    final ObjectMapper OBJECT_MAPPER = new XmlMapper();
+
+    public static class StreamWrapper329 {
+        private Stream<String> data;
+
+        @JacksonXmlElementWrapper(localName = "elements")
+        @JacksonXmlProperty(localName = "element")
+        public Stream<String> getData() {
+            return data;
+        }
+
+        public void setData(Stream<String> data) {
+            this.data = data;
+        }
+    }
+
+    public static class CollectionWrapper329 {
+        private Collection<String> data;
+
+        @JacksonXmlElementWrapper(localName = "elements")
+        @JacksonXmlProperty(localName = "element")
+        public Collection<String> getData() {
+            return data;
+        }
+
+        public void setData(Collection<String> data) {
+            this.data = data;
+        }
+    }
+
+    public static class IteratorWrapper329 {
+        private Iterator<String> data;
+
+        @JacksonXmlElementWrapper(localName = "elements")
+        @JacksonXmlProperty(localName = "element")
+        public Iterator<String> getData() {
+            return data;
+        }
+
+        public void setData(Iterator<String> data) {
+            this.data = data;
+        }
+    }
+
+    public void testCollectionSerialization() throws JsonProcessingException {
+        Collection<String> list = new ArrayList<>();
+        list.add("a");
+        list.add("b");
+
+        assertEquals("<ArrayList><item>a</item><item>b</item></ArrayList>",
+            OBJECT_MAPPER.writeValueAsString(list));
+    }
+
+    public void testListSerialization() throws JsonProcessingException {
+        List<String> list = new ArrayList<>();
+        list.add("a");
+        list.add("b");
+        assertEquals("<ArrayList><item>a</item><item>b</item></ArrayList>",
+            OBJECT_MAPPER.writeValueAsString(list));
+    }
+
+    public void testListIteratorSerialization() throws JsonProcessingException {
+        List<String> list = new ArrayList<>();
+        list.add("a");
+        list.add("b");
+        Iterator<String> listItr = list.iterator();
+
+        assertEquals("<Itr><item>a</item><item>b</item></Itr>",
+            OBJECT_MAPPER.writeValueAsString(listItr));
+    }
+
+
+    public void testStreamIteratorSerialization() throws JsonProcessingException {
+        assertEquals("<Adapter><item>a</item><item>b</item></Adapter>",
+            OBJECT_MAPPER.writeValueAsString(Stream.of("a", "b").iterator()));
+    }
+
+    // [dataformat-xml#329] : Jackson ignores JacksonXmlElementWrapper on Stream
+    public void testCollectionWrapperSerialization329() throws JsonProcessingException {
+        Collection<String> collection = new ArrayList<>();
+        collection.add("a");
+        collection.add("b");
+        CollectionWrapper329 wrapper = new CollectionWrapper329();
+        wrapper.setData(collection);
+
+        assertEquals(
+            "<CollectionWrapper329><elements>" +
+                "<element>a</element>" +
+                "<element>b</element>" +
+                "</elements></CollectionWrapper329>",
+            OBJECT_MAPPER.writeValueAsString(wrapper));
+    }
+
+    // [dataformat-xml#329] : Jackson ignores JacksonXmlElementWrapper on Stream
+    public void testIteratorWrapperSerialization329() throws JsonProcessingException {
+        Collection<String> collection = new ArrayList<>();
+        collection.add("a");
+        collection.add("b");
+        IteratorWrapper329 wrapper = new IteratorWrapper329();
+        wrapper.setData(collection.iterator());
+
+        assertEquals(
+            "<IteratorWrapper329><elements>" +
+                "<element>a</element>" +
+                "<element>b</element>" +
+                "</elements></IteratorWrapper329>",
+            OBJECT_MAPPER.writeValueAsString(wrapper));
+    }
+
+    /*
+    /**********************************************************
+    /* Stream tests, requires Jdk8Module
+    /**********************************************************
+
+    public void testStreamSerialization() throws JsonProcessingException {
+        String jsonStr = OBJECT_MAPPER.writeValueAsString(Stream.of("a", "b"));
+        assertEquals("<Head><item>a</item><item>b</item></Head>", jsonStr);
+    }
+
+    // [dataformat-xml#329] : Jackson ignores JacksonXmlElementWrapper on Stream
+    public void testStreamWrapperSerialization329() throws JsonProcessingException {
+        StreamWrapper329 wrapper = new StreamWrapper329();
+        wrapper.setData(Stream.of("a", "b"));
+
+        assertEquals(
+            "<StreamWrapper329><elements>" +
+                "<element>a</element>" +
+                "<element>b</element>" +
+                "</elements></StreamWrapper329>",
+            OBJECT_MAPPER.writeValueAsString(wrapper));
+    }
+    */
+}