android客户端使用网络数据压缩 GZIPInputStream

Gzip也是android客户端支持的方式，官网解释：GZIPInputStream此类类是用来读取在GZIP格式存储的数据，从底层的流进它的缓冲区读取和解压GZIP数据。

 

 InputStream is = ...
 GZIPInputStream zis = new GZIPInputStream(new BufferedInputStream(is));
 try {
     // Reading from 'zis' gets you the uncompressed bytes...
     processStream(zis);
 } finally {
     zis.close();
 }

1， 工具类：测试客户端是否支持GZIP编码压缩方式 & 获得支持GZIP的PrintWriter对象  
  
package freebsd;  
  
import java.io.IOException;  
import java.io.PrintWriter;  
import java.util.zip.GZIPOutputStream;  
  
import javax.servlet.ServletOutputStream;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
  
public class Utilities {  
/* 
* 测试客户端浏览器是否支持gzip的编码方式 
*/  
public static boolean isSurpported(HttpServletRequest request)  
{  
   String encodingString = request.getHeader("Accept-Encoding");  
   return (encodingString!=null) && (encodingString.indexOf("gzip")!=-1);  
}  
/* 
* 取得一个压缩的PrintWriter 
*/  
public static PrintWriter getWriter(HttpServletResponse response) throws IOException  
{  
   ServletOutputStream sos = response.getOutputStream();  
   GZIPOutputStream gzipos = new GZIPOutputStream(sos);  
   return new PrintWriter(gzipos);  
}  
  
}  
2，Servlet类，产生一个长字符串，然后在html页面中请求该servlet:  
  
import freebsd.*;  
  
import java.io.IOException;  
import java.io.PrintWriter;  
  
import javax.servlet.ServletException;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;  
  
/** 
* Servlet implementation class ServletGzip 
*/  
public class ServletGzip extends HttpServlet {  
private static final long serialVersionUID = 1L;  
         
    /** 
     * @see HttpServlet#HttpServlet() 
     */  
    public ServletGzip() {  
        super();  
        // TODO Auto-generated constructor stub  
    }  
  
/** 
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 
*/  
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
   doPost(request, response);  
}  
  
/** 
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
*/  
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {  
   response.setContentType("text/html");  
   response.setStatus(response.SC_OK);  
   PrintWriter out;  
   if(Utilities.isSurpported(request))  
   {  
    out = Utilities.getWriter(response);  
  
   //协议： 通知客户端使用gzip这种压缩方式而不是其它的，如compress  
   response.setHeader("Content-Encoding", "gzip")；  
   }else {  
    out = response.getWriter();  
   }  
  StringBuilder sBuilder = new StringBuilder();  
   for(int i=0; i!=5000; ++i)  
   {  
    sBuilder.append("Printing the long string... ...!");  
   }  
   out.println(sBuilder);  
out.close();  
}  
}