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1   /**
2    * Copyright 2011 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  package org.apache.hadoop.hbase.regionserver;
21  
22  import java.io.IOException;
23  
24  import javax.servlet.ServletException;
25  import javax.servlet.http.HttpServlet;
26  import javax.servlet.http.HttpServletRequest;
27  import javax.servlet.http.HttpServletResponse;
28  
29  import org.apache.hadoop.hbase.tmpl.regionserver.RSStatusTmpl;
30  
31  public class RSStatusServlet extends HttpServlet {
32    private static final long serialVersionUID = 1L;
33  
34    @Override
35    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
36        throws ServletException, IOException
37      {
38      HRegionServer hrs = (HRegionServer)getServletContext().getAttribute(
39          HRegionServer.REGIONSERVER);
40      assert hrs != null : "No RS in context!";
41      
42      resp.setContentType("text/html");
43      
44      if (!hrs.isOnline()) {
45        resp.getWriter().write("The RegionServer is initializing!");
46        resp.getWriter().close();
47        return;
48      }
49      
50      RSStatusTmpl tmpl = new RSStatusTmpl();
51      if (req.getParameter("format") != null)
52        tmpl.setFormat(req.getParameter("format"));
53      if (req.getParameter("filter") != null)
54        tmpl.setFilter(req.getParameter("filter"));
55      tmpl.render(resp.getWriter(), hrs);
56    }
57  
58  }