Java tutorial
/** * 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.hadoop.dfs; import java.util.*; import java.io.*; import org.apache.hadoop.util.StringUtils; import org.apache.hadoop.conf.*; import org.apache.commons.logging.*; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * This class is used in Namesystem's jetty to do fsck on namenode. */ public class FsckServlet extends HttpServlet { private static final Log LOG = LogFactory.getLog("org.apache.hadoop.dfs.FSNamesystem"); @SuppressWarnings("unchecked") public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { Map<String, String[]> pmap = request.getParameterMap(); try { ServletContext context = getServletContext(); NameNode nn = (NameNode) context.getAttribute("name.node"); Configuration conf = (Configuration) context.getAttribute("name.conf"); NamenodeFsck fscker = new NamenodeFsck(conf, nn, pmap, response); fscker.fsck(); } catch (IOException ie) { StringUtils.stringifyException(ie); LOG.warn(ie); String errMsg = "Fsck on path " + pmap.get("path") + " failed."; response.sendError(HttpServletResponse.SC_GONE, errMsg); throw ie; } } }