配置Tomcat根目录下/conf/server.xml文件:
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" URIEncoding="UTF-8"
compression="on"
compressionMinSize="2048"
noCompressionUserAgents="gozilla,traviata"
compressableMimeType="text/html,text/xml,text/javascript,text/css,text/plain,application/json"
/>
1) compression="on" 打开压缩功能
2) compressionMinSize="2048" 启用压缩的输出内容大小,这里面默认为2KB
3) noCompressionUserAgents="gozilla, traviata" 对于以下的浏览器,不启用压缩
4) compressableMimeType="text/html,text/xml" 压缩类型
一旦启用了这个压缩功能后,怎么来测试压缩是否有效呢?首先Tomcat是根据浏览器请求头中的accept-encoding来判断浏览器是否支持压缩功能,如果这个值包含有gzip,就表明浏览器支持gzip压缩内容的浏览,下面分别有二段代码进行tomcat内容是否压缩过的测试程序。
package com.triman.base.util; import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.zip.GZIPInputStream; import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.methods.GetMethod; public class TestTomcat {
public static void main(String [] args) throws HttpException, IOException{
HttpClient http = new HttpClient();
GetMethod get = new GetMethod("http://localhost:8080/sh_jasr/login.jsp");
try{
get.addRequestHeader("accept-encoding", "gzip,deflate");
get.addRequestHeader("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; Alexa Toolbar; Maxthon 2.0)");
int er = http.executeMethod(get);
if(er==200){
//第一种方案,采用读String的方式进行读取;
// System.out.println(get.getResponseContentLength());
// String html = get.getResponseBodyAsString();
// System.out.println(html);
// System.out.println(html.getBytes().length);
//第二种方案,采用stream进行读,主要针对gzip解压;
System.out.println("采用stream进行读,主要针对gzip解压;");
InputStream in=get.getResponseBodyAsStream();
// 对返回的stream流数据进行gzip解密;
GZIPInputStream gzin = new GZIPInputStream(in);
BufferedReader bin = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
String s = null;
while ((s = bin.readLine()) != null) {
System.out.println(s);
}
bin.close();
System.out.println("采用stream进行读,主要针对gzip解压;");
}
}finally{
get.releaseConnection();
}
} public static void main1(String[] args) {
try {
URL url = new URL("http://localhost:8080/sh_jasr/login.jsp");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestProperty("Accept-Encoding", "gzip,deflate");// 如果这里不设置,返回的就不是gzip的数据了,也就不用解压缩了
conn.connect();
InputStream in = conn.getInputStream();
// BufferedReader bin = new BufferedReader(new InputStreamReader(in,"UTF-8"));
// 对返回的stream流数据进行gzip解压;
GZIPInputStream gzin = new GZIPInputStream(in);
BufferedReader bin = new BufferedReader(new InputStreamReader(gzin,"UTF-8"));
String s = null;
while ((s = bin.readLine()) != null) {
System.out.println(s);
}
bin.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
执行这个测试程序,看看它所输出的是什么内容,如果输出的是一些乱码,以及打印内容的长度远小于实际的长度,那么恭喜你,你的配置生效了,你会发现你网站的浏览速度比以前快多了。
注:其实是 tomcat 6 把注释整個拿掉,让大家以为Tomcat对Gzip不再支持,其实不然,大家可以看一下http://tomcat.apache.org/tomcat-6.0-doc/config/http.html就知道,Tomcat依然支持这个功能。