Adding local file rendering support to Sample Container

java/gadgets/src/main/java/org/apache/shindig/gadgets/servlet/localfile/LocalFileServlet.java

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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
+ *
+ *   http://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 org.apache.shindig.gadgets.servlet.localfile;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.Writer;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+/**
+ * A Servlet to serve up files from the local hard drive via HTTP. Only
+ * requests from localhost will be honored.

[louiscryan, 2008/12/12 02:09:36]

Add a comment making it obvious that this should only be used in test
environments.

+ */
+public class LocalFileServlet extends HttpServlet {
+··
+  private static String LOCAL_IP = "127.0.0.1";·
+··
+  private static int BUFFER_SIZE = 1024;
+··
+  @Override
+  protected void doGet(HttpServletRequest request, HttpServletResponse response)
+      throws ServletException, IOException {
+····
+    if (!LOCAL_IP.equals(request.getRemoteAddr())) {
+      response.sendError(HttpServletResponse.SC_FORBIDDEN);
+      return;
+    }
+····
+    String path = request.getPathInfo();
+····
+    File file = new File(path);
+    if (!file.exists()) {
+      response.sendError(HttpServletResponse.SC_NOT_FOUND);
+      return;
+    }
+····
+    String contentType = getServletContext().getMimeType(path);
+····
+    BufferedInputStream in = null;
+    BufferedOutputStream out = null;
+····
+    try {
+······
+      in = new BufferedInputStream(new FileInputStream(file), BUFFER_SIZE);

[louiscryan, 2008/12/12 02:09:36]

Use the IOUtils class to do the IO handling, it has built in buffering and youll
have less code.

+      out = new BufferedOutputStream(response.getOutputStream(), BUFFER_SIZE);
+      if (contentType != null) {
+        response.setContentType(contentType);
+      }
+      response.setContentLength(in.available());
+      byte[] buffer = new byte[BUFFER_SIZE];
+      for (int read; (read = in.read(buffer)) != -1;) {
+        out.write(buffer, 0, read);
+      }
+      out.flush();
+······
+    } finally {
+      if (in != null) {
+        in.close();
+      }
+      if (out != null) {
+        out.close();
+      }
+    }
+  }
+}