package com.wordyun.web.filter; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.util.zip.GZIPOutputStream; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.WriteListener; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpServletResponseWrapper; /** * GZIP压缩 * @author Administrator * */ public class GzipFilter implements Filter { @Override public void init(FilterConfig filterConfig) throws ServletException { // TODO Auto-generated method stub } @Override public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException { HttpServletRequest request=(HttpServletRequest) req; HttpServletResponse response=(HttpServletResponse) resp; MyResponse myResponse=new MyResponse(response); chain.doFilter(request, myResponse); byte[] mb=myResponse.getByte(); System.out.println(mb.length); byte[] gb=getGzipByte(mb); System.out.println(gb.length); response.setHeader("content-encoding", "gzip"); response.setHeader("content-length", gb.length+""); response.getOutputStream().write(gb); } private byte[] getGzipByte(byte[] mb){ try { ByteArrayOutputStream bout=new ByteArrayOutputStream(); GZIPOutputStream gzipout = new GZIPOutputStream(bout); gzipout.write(mb); gzipout.close(); return bout.toByteArray(); } catch (IOException e) { throw new RuntimeException(e); } } class MyResponse extends HttpServletResponseWrapper{ private ByteArrayOutputStream bout=new ByteArrayOutputStream(); private PrintWriter pw=null; private HttpServletResponse response; public MyResponse(HttpServletResponse response) { super(response); this.response=response; } @Override public ServletOutputStream getOutputStream() throws IOException { return new ServletOutputStream(){ @Override public boolean isReady() { // TODO Auto-generated method stub return false; } @Override public void setWriteListener(WriteListener writeListener) { // TODO Auto-generated method stub } @Override public void write(int b) throws IOException { bout.write(b); } }; } @Override public PrintWriter getWriter() throws IOException { pw=new PrintWriter(new OutputStreamWriter(bout, "utf-8")); return pw; } public byte[] getByte(){ if(pw!=null) pw.close(); return bout.toByteArray(); } } @Override public void destroy() { // TODO Auto-generated method stub } }
在web.xml配置过滤器
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> <filter> <filter-name>GzipFilter</filter-name> <filter-class>com.wordyun.web.filter.GzipFilter</filter-class> </filter> <filter-mapping> <filter-name>GzipFilter</filter-name> <url-pattern>*.jsp</url-pattern> </filter-mapping> <filter-mapping> <filter-name>GzipFilter</filter-name> <url-pattern>*.html</url-pattern> </filter-mapping> <filter-mapping> <filter-name>GzipFilter</filter-name> <url-pattern>*.js</url-pattern> </filter-mapping> <filter-mapping> <filter-name>GzipFilter</filter-name> <url-pattern>*.css</url-pattern> </filter-mapping> </web-app>