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 java.io.IOException; 021import javax.servlet.Filter; 022import javax.servlet.FilterChain; 023import javax.servlet.FilterConfig; 024import javax.servlet.ServletException; 025import javax.servlet.ServletRequest; 026import javax.servlet.ServletResponse; 027import javax.servlet.http.HttpServletResponse; 028import org.apache.hadoop.hbase.HBaseInterfaceAudience; 029import org.apache.hadoop.hbase.util.EnvironmentEdgeManager; 030import org.apache.yetus.audience.InterfaceAudience; 031 032@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG) 033public class NoCacheFilter implements Filter { 034 035 /** 036 * Constant for the configuration property that indicates no-store cache control is enabled. 037 */ 038 public static final String NO_STORE = "no-store.enable"; 039 040 private boolean noStoreEnabled = false; 041 042 @Override 043 public void init(FilterConfig filterConfig) throws ServletException { 044 this.noStoreEnabled = Boolean.valueOf(filterConfig.getInitParameter(NO_STORE)); 045 } 046 047 @Override 048 public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) 049 throws IOException, ServletException { 050 HttpServletResponse httpRes = (HttpServletResponse) res; 051 StringBuilder header = new StringBuilder("no-cache"); 052 if (noStoreEnabled) { 053 header.append(", no-store, max-age=0"); 054 } 055 httpRes.setHeader("Cache-Control", header.toString()); 056 long now = EnvironmentEdgeManager.currentTime(); 057 httpRes.addDateHeader("Expires", now); 058 httpRes.addDateHeader("Date", now); 059 httpRes.addHeader("Pragma", "no-cache"); 060 chain.doFilter(req, res); 061 } 062 063 @Override 064 public void destroy() { 065 } 066}