HttpDownloader.java

package com.jiuqi.njt.util;

import java.io.BufferedReader;  
import java.io.IOException;  
import java.io.InputStreamReader;  
import java.net.HttpURLConnection;  
import java.net.URL;  
  
public class HttpDownloader {  
    // 根据URL下载文件,前提是这个文件当中的内容是文本,函数的返回值就是文本当中的内容  
    // 1.创建一个URL对象  
    // 2.通过URL对象,创建一个HttpURLConnection对象  
    // 3.得到InputStream  
    // 4.从InputStream当中读取数据  
    private URL url;  
  
    public String download(String urlStr) {  
        StringBuffer sb = new StringBuffer();  
        String line = null;  
        BufferedReader buffer = null;  
        try {  
            url = new URL(urlStr);  
            HttpURLConnection urlConn = (HttpURLConnection) url  
                    .openConnection();  
            buffer = new BufferedReader(new InputStreamReader(  
                    urlConn.getInputStream()));  
            while ((line = buffer.readLine()) != null) {  
                sb.append(line);  
            }  
        } catch (Exception e) {  
            e.printStackTrace();  
        } finally {  
            try {  
                buffer.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
        return sb.toString();  
    }  
}