feat: Tracking the bytes in output stream from representation service in BoxFile

Author: Abdul Haleem Sheikh

src/main/java/com/box/sdk/BinaryBodyUtils.java

@@ -46,6 +46,28 @@ static void writeStream(BoxAPIResponse response, OutputStream output, ProgressLi
         }
     }
 
+    /**
+     * Writes response body bytes to output stream. After all closes the input stream.
+     *
+     * @param response Response that is going to be written.
+     * @param output   Output stream.
+     * @param listener Listener that will be notified on writing response. Can be null.
+     */
+
+    static void writeStreamWithContentLength(BoxAPIResponse response, OutputStream output, ProgressListener listener) {
+        try {
+            InputStream input;
+            if (listener != null) {
+                input = response.getBody(listener);
+            } else {
+                input = response.getBody();
+            }
+            writeStreamTo(input, output, response.getContentLength());
+        } finally {
+            response.close();
+        }
+    }
+
     /**
      * Writes content of input stream to provided output. Method is NOT closing input stream.
      *
@@ -71,4 +93,31 @@ static void writeStreamTo(InputStream input, OutputStream output) {
             }
         }
     }
+
+    static void writeStreamTo(InputStream input, OutputStream output, long expectedLength) {
+        long totalBytesRead = 0;
+        if (expectedLength < 0) {
+            throw new RuntimeException("No Data bytes in stream");
+        }
+        try {
+            byte[] buffer = new byte[8192];
+            for (int n = input.read(buffer); n != -1; n = input.read(buffer)) {
+                output.write(buffer, 0, n);
+                totalBytesRead += n;  // Track the total bytes read
+            }
+            if (totalBytesRead != expectedLength) {
+                throw new IOException("Stream ended prematurely. Expected " + expectedLength
+                        + " bytes, but read " + totalBytesRead + " bytes.");
+            }
+        } catch (IOException e) {
+            throw new RuntimeException("Error during streaming: " + e.getMessage(), e);
+        } finally {
+            try {
+                input.close();
+                output.close();
+            } catch (IOException closeException) {
+                throw new RuntimeException("IOException during stream close", closeException);
+            }
+        }
+    }
 }

src/main/java/com/box/sdk/BoxFile.java

@@ -1,6 +1,7 @@
 package com.box.sdk;
 
 import static com.box.sdk.BinaryBodyUtils.writeStream;
+import static com.box.sdk.BinaryBodyUtils.writeStreamWithContentLength;
 import static com.box.sdk.http.ContentType.APPLICATION_JSON;
 import static com.box.sdk.http.ContentType.APPLICATION_JSON_PATCH;
 import static com.eclipsesource.json.Json.NULL;
@@ -602,7 +603,7 @@ private void makeRepresentationContentRequest(
             URL repURL = new URL(representationURLTemplate.replace("{+asset_path}", assetPath));
             BoxAPIRequest repContentReq = new BoxAPIRequest(this.getAPI(), repURL, HttpMethod.GET);
             BoxAPIResponse response = repContentReq.send();
-            writeStream(response, output);
+            writeStreamWithContentLength(response, output, null);
         } catch (MalformedURLException ex) {
 
             throw new BoxAPIException("Could not generate representation content URL");

src/test/java/com/box/sdk/BoxFileTest.java

@@ -433,6 +433,7 @@ public void testGetThumbnailSucceeds() {
                 ))
                 .willReturn(WireMock.aResponse()
                     .withHeader("Content-Type", "image/jpg")
+                    .withHeader("Content-Length", String.valueOf(13))
                     .withBody("This is a JPG")
                     .withStatus(200))
         );
@@ -517,6 +518,7 @@ public void testGetRepresentationContentSuccess() {
                 ))
                 .willReturn(WireMock.aResponse()
                     .withHeader("Content-Type", "image/jpg")
+                    .withHeader("Content-Length", String.valueOf(13))
                     .withBody("This is a JPG")
                     .withStatus(200))
         );