1、主要应用getContentType获取相应的网页编码方式：

pageUrl=new URL(urlString);

HttpURLConnection uc = (HttpURLConnection) pageUrl.openConnection();

String encoding=uc.getContentType();

2、再提取charset子串（这里使用"charset="，由于网页中的大小写不敏感，所以最好用正则表达式修改一下）

encoding=encoding.substring(encoding.indexOf("charset=")+8).trim();
//System.out.println("+"+encoding+"+");
// 创建网络流
BufferedReader reader=
new BufferedReader(new InputStreamReader(pageUrl.openStream(),encoding));

3、下面是源代码，注释的很清楚：

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 import java.io.UnsupportedEncodingException;
 5 import java.net.HttpURLConnection;
 6 import java.net.MalformedURLException;
 7 import java.net.URL;
 9 public class PageString {
10     private StringBuffer strBuf=new StringBuffer();
11     private URL pageUrl=null;
12     public PageString(String urlString){
13         try {
14             //System.out.println(urlString);
15             pageUrl=new URL(urlString);
16             try {
17                 //获取网页的编码方式，这里可以解决乱码问题
18                 HttpURLConnection uc = (HttpURLConnection) pageUrl.openConnection();
19                 String encoding=uc.getContentType();
20                 encoding=encoding.substring(encoding.indexOf("charset=")+8).trim();
21                 //System.out.println("+"+encoding+"+");
22                 // 创建网络流
23                 BufferedReader reader=
24                 new BufferedReader(new InputStreamReader(pageUrl.openStream(),encoding));
25                 String line;
26                 // 读取网页内容
27                 //new StringBuffer();
28                 while((line=reader.readLine())!=null){
29                     //System.out.println(line);
30                    strBuf.append(line+"\t\n");
31                 }
32                 } catch (IOException e) {
33                 // TODO Auto-generated catch block
34                 e.printStackTrace();
35                 }
36         } catch (MalformedURLException e) {
37             // TODO Auto-generated catch block
38             e.printStackTrace();
39         }
40     }
41     public StringBuffer getStrBuf() throws UnsupportedEncodingException {
42         //System.out.println(new String(strBuf.toString().getBytes("gb2312")).toString());
43         return this.strBuf;
44     }