Allow creation of custom input/output streams in HurlStack (#328)

Refactor the InputStream and OutputStream creation during HurlStack request execution into protected helper methods. This allows subclasses to override these methods, e.g. to monitor the progress of writing request bytes to the OutputStream and reading response bytes from the InputStream, as desired.

Co-authored-by: Jeff Davidson <[email protected]>

src/main/java/com/android/volley/toolbox/HurlStack.java

@@ -25,6 +25,7 @@
 import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.ArrayList;
@@ -111,7 +112,7 @@ public HttpResponse executeRequest(Request<?> request, Map<String, String> addit
                     responseCode,
                     convertHeaders(connection.getHeaderFields()),
                     connection.getContentLength(),
-                    new UrlConnectionInputStream(connection));
+                    createInputStream(request, connection));
         } finally {
             if (!keepConnectionOpen) {
                 connection.disconnect();
@@ -168,6 +169,19 @@ public void close() throws IOException {
         }
     }
 
+    /**
+     * Create and return an InputStream from which the response will be read.
+     *
+     * <p>May be overridden by subclasses to manipulate or monitor this input stream.
+     *
+     * @param request current request.
+     * @param connection current connection of request.
+     * @return an InputStream from which the response will be read.
+     */
+    protected InputStream createInputStream(Request<?> request, HttpURLConnection connection) {
+        return new UrlConnectionInputStream(connection);
+    }
+
     /**
      * Initializes an {@link InputStream} from the given {@link HttpURLConnection}.
      *
@@ -223,7 +237,7 @@ private HttpURLConnection openConnection(URL url, Request<?> request) throws IOE
     // NOTE: Any request headers added here (via setRequestProperty or addRequestProperty) should be
     // checked against the existing properties in the connection and not overridden if already set.
     @SuppressWarnings("deprecation")
-    /* package */ static void setConnectionParametersForRequest(
+    /* package */ void setConnectionParametersForRequest(
             HttpURLConnection connection, Request<?> request) throws IOException, AuthFailureError {
         switch (request.getMethod()) {
             case Method.DEPRECATED_GET_OR_POST:
@@ -270,15 +284,15 @@ private HttpURLConnection openConnection(URL url, Request<?> request) throws IOE
         }
     }
 
-    private static void addBodyIfExists(HttpURLConnection connection, Request<?> request)
+    private void addBodyIfExists(HttpURLConnection connection, Request<?> request)
             throws IOException, AuthFailureError {
         byte[] body = request.getBody();
         if (body != null) {
             addBody(connection, request, body);
         }
     }
 
-    private static void addBody(HttpURLConnection connection, Request<?> request, byte[] body)
+    private void addBody(HttpURLConnection connection, Request<?> request, byte[] body)
             throws IOException {
         // Prepare output. There is no need to set Content-Length explicitly,
         // since this is handled by HttpURLConnection using the size of the prepared
@@ -289,8 +303,25 @@ private static void addBody(HttpURLConnection connection, Request<?> request, by
             connection.setRequestProperty(
                     HttpHeaderParser.HEADER_CONTENT_TYPE, request.getBodyContentType());
         }
-        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
+        DataOutputStream out =
+                new DataOutputStream(createOutputStream(request, connection, body.length));
         out.write(body);
         out.close();
     }
+
+    /**
+     * Create and return an OutputStream to which the request body will be written.
+     *
+     * <p>May be overridden by subclasses to manipulate or monitor this output stream.
+     *
+     * @param request current request.
+     * @param connection current connection of request.
+     * @param length size of stream to write.
+     * @return an OutputStream to which the request body will be written.
+     * @throws IOException if an I/O error occurs while creating the stream.
+     */
+    protected OutputStream createOutputStream(
+            Request<?> request, HttpURLConnection connection, int length) throws IOException {
+        return connection.getOutputStream();
+    }
 }

src/test/java/com/android/volley/toolbox/HurlStackTest.java

@@ -17,18 +17,24 @@
 package com.android.volley.toolbox;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import com.android.volley.Header;
+import com.android.volley.Request;
 import com.android.volley.Request.Method;
 import com.android.volley.mock.TestRequest;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.FilterInputStream;
+import java.io.FilterOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.SocketTimeoutException;
 import java.net.URL;
@@ -62,6 +68,26 @@ public void setUp() throws Exception {
                     protected HttpURLConnection createConnection(URL url) {
                         return mMockConnection;
                     }
+
+                    @Override
+                    protected InputStream createInputStream(
+                            Request<?> request, HttpURLConnection connection) {
+                        return new MonitoringInputStream(
+                                super.createInputStream(request, connection));
+                    }
+
+                    @Override
+                    protected OutputStream createOutputStream(
+                            Request<?> request, HttpURLConnection connection, int length)
+                            throws IOException {
+                        if (request instanceof MonitoredRequest) {
+                            return new MonitoringOutputStream(
+                                    super.createOutputStream(request, connection, length),
+                                    (MonitoredRequest) request,
+                                    length);
+                        }
+                        return super.createOutputStream(request, connection, length);
+                    }
                 };
     }
 
@@ -70,7 +96,7 @@ public void connectionForDeprecatedGetRequest() throws Exception {
         TestRequest.DeprecatedGet request = new TestRequest.DeprecatedGet();
         assertEquals(request.getMethod(), Method.DEPRECATED_GET_OR_POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection, never()).setRequestMethod(anyString());
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -80,7 +106,7 @@ public void connectionForDeprecatedPostRequest() throws Exception {
         TestRequest.DeprecatedPost request = new TestRequest.DeprecatedPost();
         assertEquals(request.getMethod(), Method.DEPRECATED_GET_OR_POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -90,7 +116,7 @@ public void connectionForGetRequest() throws Exception {
         TestRequest.Get request = new TestRequest.Get();
         assertEquals(request.getMethod(), Method.GET);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("GET");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -100,7 +126,7 @@ public void connectionForPostRequest() throws Exception {
         TestRequest.Post request = new TestRequest.Post();
         assertEquals(request.getMethod(), Method.POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -110,7 +136,7 @@ public void connectionForPostWithBodyRequest() throws Exception {
         TestRequest.PostWithBody request = new TestRequest.PostWithBody();
         assertEquals(request.getMethod(), Method.POST);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("POST");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -120,7 +146,7 @@ public void connectionForPutRequest() throws Exception {
         TestRequest.Put request = new TestRequest.Put();
         assertEquals(request.getMethod(), Method.PUT);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PUT");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -130,7 +156,7 @@ public void connectionForPutWithBodyRequest() throws Exception {
         TestRequest.PutWithBody request = new TestRequest.PutWithBody();
         assertEquals(request.getMethod(), Method.PUT);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PUT");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -140,7 +166,7 @@ public void connectionForDeleteRequest() throws Exception {
         TestRequest.Delete request = new TestRequest.Delete();
         assertEquals(request.getMethod(), Method.DELETE);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("DELETE");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -150,7 +176,7 @@ public void connectionForHeadRequest() throws Exception {
         TestRequest.Head request = new TestRequest.Head();
         assertEquals(request.getMethod(), Method.HEAD);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("HEAD");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -160,7 +186,7 @@ public void connectionForOptionsRequest() throws Exception {
         TestRequest.Options request = new TestRequest.Options();
         assertEquals(request.getMethod(), Method.OPTIONS);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("OPTIONS");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -170,7 +196,7 @@ public void connectionForTraceRequest() throws Exception {
         TestRequest.Trace request = new TestRequest.Trace();
         assertEquals(request.getMethod(), Method.TRACE);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("TRACE");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -180,7 +206,7 @@ public void connectionForPatchRequest() throws Exception {
         TestRequest.Patch request = new TestRequest.Patch();
         assertEquals(request.getMethod(), Method.PATCH);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PATCH");
         verify(mMockConnection, never()).setDoOutput(true);
     }
@@ -190,7 +216,7 @@ public void connectionForPatchWithBodyRequest() throws Exception {
         TestRequest.PatchWithBody request = new TestRequest.PatchWithBody();
         assertEquals(request.getMethod(), Method.PATCH);
 
-        HurlStack.setConnectionParametersForRequest(mMockConnection, request);
+        mHurlStack.setConnectionParametersForRequest(mMockConnection, request);
         verify(mMockConnection).setRequestMethod("PATCH");
         verify(mMockConnection).setDoOutput(true);
     }
@@ -256,4 +282,56 @@ public void convertHeaders() {
         expected.add(new Header("HeaderB", "ValueB_2"));
         assertEquals(expected, result);
     }
+
+    @Test
+    public void interceptResponseStream() throws Exception {
+        when(mMockConnection.getResponseCode()).thenReturn(HttpURLConnection.HTTP_OK);
+        when(mMockConnection.getInputStream())
+                .thenReturn(new ByteArrayInputStream("hello".getBytes(StandardCharsets.UTF_8)));
+        HttpResponse response =
+                mHurlStack.executeRequest(
+                        new TestRequest.Get(), Collections.<String, String>emptyMap());
+        assertTrue(response.getContent() instanceof MonitoringInputStream);
+    }
+
+    @Test
+    public void interceptRequestStream() throws Exception {
+        MonitoredRequest request = new MonitoredRequest();
+        mHurlStack.executeRequest(request, Collections.<String, String>emptyMap());
+        assertTrue(request.totalRequestBytes > 0);
+        assertEquals(request.totalRequestBytes, request.requestBytesRead);
+    }
+
+    private static class MonitoringInputStream extends FilterInputStream {
+        private MonitoringInputStream(InputStream in) {
+            super(in);
+        }
+    }
+
+    private static class MonitoringOutputStream extends FilterOutputStream {
+        private MonitoredRequest request;
+
+        private MonitoringOutputStream(OutputStream out, MonitoredRequest request, int length) {
+            super(out);
+            this.request = request;
+            this.request.totalRequestBytes = length;
+        }
+
+        @Override
+        public void write(int b) throws IOException {
+            this.request.requestBytesRead++;
+            out.write(b);
+        }
+
+        @Override
+        public void write(byte[] b, int off, int len) throws IOException {
+            this.request.requestBytesRead += len;
+            out.write(b, off, len);
+        }
+    }
+
+    private static class MonitoredRequest extends TestRequest.PostWithBody {
+        int requestBytesRead = 0;
+        int totalRequestBytes = 0;
+    }
 }