Add option to return raw stream from response (#579)

* Add option to return raw stream

* fix formatting

Author: ajaaym

google-http-client/src/main/java/com/google/api/client/http/HttpRequest.java

@@ -224,6 +224,16 @@ static String executeAndGetValueOfSomeCustomHeader(HttpRequest request) {
   /** OpenCensus tracing component. */
   private final Tracer tracer = OpenCensusUtils.getTracer();
 
+  /**
+   * Determines whether {@link HttpResponse#getContent()} of this request should return raw
+   * input stream or not.
+   *
+   * <p>
+   *   It is {@code false} by default.
+   * </p>
+   */
+  private boolean responseReturnRawInputStream = false;
+
   /**
    * @param transport HTTP transport
    * @param requestMethod HTTP request method or {@code null} for none
@@ -835,6 +845,31 @@ public HttpRequest setSuppressUserAgentSuffix(boolean suppressUserAgentSuffix) {
     return this;
   }
 
+  /**
+   * Returns whether {@link HttpResponse#getContent()} should return raw input stream for this
+   * request.
+   *
+   * @since 1.29
+   */
+  public boolean getResponseReturnRawInputStream() {
+    return responseReturnRawInputStream;
+  }
+
+  /**
+   * Sets whether {@link HttpResponse#getContent()} should return raw input stream for this
+   * request.
+   *
+   * <p>
+   * The default value is {@code false}.
+   * </p>
+   *
+   * @since 1.29
+   */
+  public HttpRequest setResponseReturnRawInputStream(boolean responseReturnRawInputStream) {
+    this.responseReturnRawInputStream = responseReturnRawInputStream;
+    return this;
+  }
+
   /**
    * Execute the HTTP request and returns the HTTP response.
    *

google-http-client/src/main/java/com/google/api/client/http/HttpResponse.java

@@ -82,6 +82,9 @@ public final class HttpResponse {
   /** HTTP request. */
   private final HttpRequest request;
 
+  /** Whether {@link #getContent()} should return raw input stream. */
+  private final boolean returnRawInputStream;
+
   /**
    * Determines the limit to the content size that will be logged during {@link #getContent()}.
    *
@@ -118,6 +121,7 @@ public final class HttpResponse {
 
   HttpResponse(HttpRequest request, LowLevelHttpResponse response) throws IOException {
     this.request = request;
+    this.returnRawInputStream = request.getResponseReturnRawInputStream();
     contentLoggingLimit = request.getContentLoggingLimit();
     loggingEnabled = request.isLoggingEnabled();
     this.response = response;
@@ -359,7 +363,8 @@ public InputStream getContent() throws IOException {
         try {
           // gzip encoding (wrap content with GZipInputStream)
           String contentEncoding = this.contentEncoding;
-          if (contentEncoding != null && contentEncoding.contains("gzip")) {
+          if (!returnRawInputStream && contentEncoding != null && contentEncoding
+              .contains("gzip")) {
             lowLevelResponseContent = new GZIPInputStream(lowLevelResponseContent);
           }
           // logging (wrap content with LoggingInputStream)

google-http-client/src/test/java/com/google/api/client/http/HttpResponseTest.java

@@ -29,6 +29,7 @@
 import java.text.NumberFormat;
 import java.util.Arrays;
 import java.util.logging.Level;
+import java.util.zip.GZIPInputStream;
 import junit.framework.TestCase;
 
 /**
@@ -400,4 +401,26 @@ public LowLevelHttpResponse execute() throws IOException {
         transport.createRequestFactory().buildHeadRequest(HttpTesting.SIMPLE_GENERIC_URL);
     request.execute().getContent();
   }
+
+  public void testGetContent_gzipEncoding_ReturnRawStream() throws IOException {
+    HttpTransport transport = new MockHttpTransport() {
+      @Override
+      public LowLevelHttpRequest buildRequest(String method, final String url) throws IOException {
+        return new MockLowLevelHttpRequest() {
+          @Override
+          public LowLevelHttpResponse execute() throws IOException {
+            MockLowLevelHttpResponse result = new MockLowLevelHttpResponse();
+            result.setContent("");
+            result.setContentEncoding("gzip");
+            result.setContentType("text/plain");
+            return result;
+          }
+        };
+      }
+    };
+    HttpRequest request =
+        transport.createRequestFactory().buildHeadRequest(HttpTesting.SIMPLE_GENERIC_URL);
+    request.setResponseReturnRawInputStream(true);
+    assertFalse("it should not decompress stream", request.execute().getContent() instanceof GZIPInputStream);
+  }
 }