解决java用url中读取html源码时的乱码问题

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：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class PageString {
    private StringBuffer strBuf=new StringBuffer();
    private URL pageUrl=null;
    public PageString(String urlString){
        try {
            //System.out.println(urlString);
            pageUrl=new URL(urlString);
            try {
                //获取网页的编码方式，这里可以解决乱码问题
                HttpURLConnection uc = (HttpURLConnection) pageUrl.openConnection();
                String encoding=uc.getContentType();
                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));
                String line;
                // 读取网页内容
                //new StringBuffer();
                while((line=reader.readLine())!=null){
                    //System.out.println(line);
                   strBuf.append(line+"\t\n");
                }
                } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
                }
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    public StringBuffer getStrBuf() throws UnsupportedEncodingException {
        //System.out.println(new String(strBuf.toString().getBytes("gb2312")).toString());
        return this.strBuf;
    }
}