Use try-with-resources statements

- instead of finally blocks
- in cases of missing try-finally

Change-Id: I94f481a33d8e6a3180c436245d6e95e4d525280c

gerrit-httpd/src/main/java/com/google/gerrit/httpd/restapi/RestApiServlet.java

@@ -522,8 +522,7 @@ public class RestApiServlet extends HttpServlet {
       IllegalArgumentException, NoSuchMethodException, IllegalAccessException,
       InstantiationException, InvocationTargetException, MethodNotAllowedException {
     if (isType(JSON_TYPE, req.getContentType())) {
-      BufferedReader br = req.getReader();
-      try {
+      try (BufferedReader br = req.getReader()) {
         JsonReader json = new JsonReader(br);
         json.setLenient(true);
 
@@ -537,8 +536,6 @@ public class RestApiServlet extends HttpServlet {
           return parseString(json.nextString(), type);
         }
         return OutputFormat.JSON.newGson().fromJson(json, type);
-      } finally {
-        br.close();
       }
     } else if (("PUT".equals(req.getMethod()) || "POST".equals(req.getMethod()))
         && acceptsRawInput(type)) {
@@ -548,8 +545,7 @@ public class RestApiServlet extends HttpServlet {
     } else if (hasNoBody(req)) {
       return createInstance(type);
     } else if (isType("text/plain", req.getContentType())) {
-      BufferedReader br = req.getReader();
-      try {
+      try (BufferedReader br = req.getReader()) {
         char[] tmp = new char[256];
         StringBuilder sb = new StringBuilder();
         int n;
@@ -557,8 +553,6 @@ public class RestApiServlet extends HttpServlet {
           sb.append(tmp, 0, n);
         }
         return parseString(sb.toString(), type);
-      } finally {
-        br.close();
       }
     } else if ("POST".equals(req.getMethod())
         && isType(FORM_TYPE, req.getContentType())) {
@@ -772,11 +766,8 @@ public class RestApiServlet extends HttpServlet {
       }
 
       if (req == null || !"HEAD".equals(req.getMethod())) {
-        OutputStream dst = res.getOutputStream();
-        try {
+        try (OutputStream dst = res.getOutputStream()) {
           bin.writeTo(dst);
-        } finally {
-          dst.close();
         }
       }
     } finally {
@@ -1078,9 +1069,9 @@ public class RestApiServlet extends HttpServlet {
   private static BinaryResult compress(BinaryResult bin)
       throws IOException {
     TemporaryBuffer.Heap buf = heap(HEAP_EST_SIZE, 20 << 20);
-    GZIPOutputStream gz = new GZIPOutputStream(buf);
-    bin.writeTo(gz);
-    gz.close();
+    try (GZIPOutputStream gz = new GZIPOutputStream(buf)) {
+      bin.writeTo(gz);
+    }
     return asBinaryResult(buf).setContentType(bin.getContentType());
   }