十六、从网络中获取网页数据

从网络中获取网页数据时，网页有可能使用GZIP压缩技术对页面进行压缩，这样就会减小通过网络传输的数据量，提高浏览的速度。因此在获取网络数据时要对其进行判断，对GZIP格式的数据使用GZIPInputStream对其特殊处理，否则在获取数据可能出现乱码哦.

                 

 以下为网络中获取网页数据的案例代码

 

package com.ljq.test;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;

/**
 * 从网络中获取网页数据
 * 
 * @author jiqinlin
 *
 */
public class InternetTest2 {

    @SuppressWarnings("static-access")
    public static void main(String[] args) throws Exception {
        String result = "";
        //URL url = new URL("http://www.sohu.com");
        URL url = new URL("http://www.ku6.com/");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setConnectTimeout(6* 1000);//设置连接超时
        if (conn.getResponseCode() != 200) throw new RuntimeException("请求url失败");
        InputStream is = conn.getInputStream();//得到网络返回的输入流
        if("gzip".equals(conn.getContentEncoding())){
            result = new InternetTest2().readDataForZgip(is, "GBK");
        }else {
            result = new InternetTest2().readData(is, "GBK");
        }
        conn.disconnect();
        System.out.println(result);
        System.err.println("ContentEncoding: " + conn.getContentEncoding());
    }
    
    //第一个参数为输入流,第二个参数为字符集编码
    public static String readData(InputStream inSream, String charsetName) throws Exception{
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = -1;
        while( (len = inSream.read(buffer)) != -1 ){
            outStream.write(buffer, 0, len);
        }
        byte[] data = outStream.toByteArray();
        outStream.close();
        inSream.close();
        return new String(data, charsetName);
    }
    
    //第一个参数为输入流,第二个参数为字符集编码
    public static String readDataForZgip(InputStream inStream, String charsetName) throws Exception{
        GZIPInputStream gzipStream = new GZIPInputStream(inStream);
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer =new  byte[1024];
        int len = -1;
        while ((len = gzipStream.read(buffer))!=-1) {
            outStream.write(buffer, 0, len);
        }
        byte[] data = outStream.toByteArray();
        outStream.close();
        gzipStream.close();
        inStream.close();
        return new String(data, charsetName);
    }

}