001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.http;
019
020import javax.servlet.Filter;
021import javax.servlet.FilterChain;
022import javax.servlet.FilterConfig;
023import javax.servlet.ServletException;
024import javax.servlet.ServletRequest;
025import javax.servlet.ServletResponse;
026import javax.servlet.http.HttpServletResponse;
027import java.io.IOException;
028
029import org.apache.yetus.audience.InterfaceAudience;
030import org.apache.hadoop.hbase.HBaseInterfaceAudience;
031
032@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
033public class NoCacheFilter implements Filter {
034
035  @Override
036  public void init(FilterConfig filterConfig) throws ServletException {
037  }
038
039  @Override
040  public void doFilter(ServletRequest req, ServletResponse res,
041                       FilterChain chain)
042    throws IOException, ServletException {
043    HttpServletResponse httpRes = (HttpServletResponse) res;
044    httpRes.setHeader("Cache-Control", "no-cache");
045    long now = System.currentTimeMillis();
046    httpRes.addDateHeader("Expires", now);
047    httpRes.addDateHeader("Date", now);
048    httpRes.addHeader("Pragma", "no-cache");
049    chain.doFilter(req, res);
050  }
051
052  @Override
053  public void destroy() {
054  }
055
056}