Another version that directly reads BLOB without going through an int…

…ermediate object.

src/main/java/org/kohsuke/github/GHRepository.java

@@ -31,6 +31,7 @@
 
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.InterruptedIOException;
 import java.io.Reader;
@@ -818,13 +819,30 @@ public GHTree getTreeRecursive(String sha, int recursive) throws IOException {
     }
 
     /**
+     * Obtains the metadata & the content of a blob.
+     *
+     * <p>
+     * This method retrieves the whole content in memory, so beware when you are dealing with large BLOB.
+     *
      * @see <a href="https://developer.github.com/v3/git/blobs/#get-a-blob">Get a blob</a>
+     * @see #readBlob(String)
      */
     public GHBlob getBlob(String blobSha) throws IOException {
         String target = getApiTailUrl("git/blobs/" + blobSha);
         return root.retrieve().to(target, GHBlob.class);
     }
 
+    /**
+     * Reads the content of a blob as a stream for better efficiency.
+     *
+     * @see <a href="https://developer.github.com/v3/git/blobs/#get-a-blob">Get a blob</a>
+     * @see #getBlob(String)
+     */
+    public InputStream readBlob(String blobSha) throws IOException {
+        String target = getApiTailUrl("git/blobs/" + blobSha);
+        return root.retrieve().withHeader("Accept","application/vnd.github.VERSION.raw").asStream(target);
+    }
+
     /**
      * Gets a commit object in this repository.
      */

src/test/java/org/kohsuke/github/AppTest.java

@@ -12,6 +12,7 @@
 import org.kohsuke.github.GHOrganization.Permission;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.URL;
 import java.util.*;
 import java.util.Map.Entry;
@@ -903,6 +904,26 @@ public void listOrgMemberships() throws Exception {
         }
     }
 
+    @Test
+    public void blob() throws Exception {
+        GHRepository r = gitHub.getRepository("kohsuke/github-api");
+        String sha1 = "a12243f2fc5b8c2ba47dd677d0b0c7583539584d";
+
+        assertBlobContent(r.readBlob(sha1));
+
+        GHBlob blob = r.getBlob(sha1);
+        assertBlobContent(blob.read());
+        assertThat(blob.getSha(),is("a12243f2fc5b8c2ba47dd677d0b0c7583539584d"));
+        assertThat(blob.getSize(),is(1104L));
+    }
+
+    private void assertBlobContent(InputStream is) throws Exception {
+        String content = new String(IOUtils.toByteArray(is),"UTF-8");
+        assertThat(content,containsString("Copyright (c) 2011- Kohsuke Kawaguchi and other contributors"));
+        assertThat(content,containsString("FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR"));
+        assertThat(content.length(),is(1104));
+    }
+
     private void kohsuke() {
         String login = getUser().getLogin();
         Assume.assumeTrue(login.equals("kohsuke") || login.equals("kohsuke2"));