// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package com.google.sps.servlets;

import com.google.appengine.api.blobstore.BlobKey;
import com.google.appengine.api.blobstore.BlobstoreService;
import com.google.appengine.api.blobstore.BlobstoreServiceFactory;
import com.google.sps.data.HttpServletUtils;
import java.io.IOException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet that serves a blob from a blobKey, e.g. <img src="/serve-blob?blobKey=${blobKey}">
 */
@WebServlet("/serve-blob")
public class ServeBlobServlet extends HttpServlet {

  @Override
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
    String blobString = HttpServletUtils.getParameter(request, "blobKey", "");
    
    if (blobString.isEmpty()) {
      response.sendError(HttpServletResponse.SC_BAD_REQUEST);
      return;
    }

    BlobstoreService blobstoreService = BlobstoreServiceFactory.getBlobstoreService();

    BlobKey blobKey = new BlobKey(blobString);
    blobstoreService.serve(blobKey, response);
  }
}

@@ -667,16 +667,85 @@
 lobKey;%0A
+import com.google.appengine.api.blobstore.BlobstoreFailureException;%0A
 import c
@@ -1605,16 +1605,28 @@
 %0A    %7D%0A%0A
+    try %7B%0A  
     Blob
@@ -1705,24 +1705,26 @@
 ice();%0A%0A    
+  
 BlobKey blob
@@ -1758,16 +1758,18 @@
 g);%0A    
+ 
+ 
 blobstor
@@ -1803,14 +1803,223 @@
 ponse);%0A
+    %7D catch (BlobstoreFailureException e) %7B%0A      System.out.println(%22Problems communicating with Blobstore: %22 + e);%0A      response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);%0A      return;%0A    %7D%0A
   %7D%0A%7D%0A

Add try-catch in serveBlob