通过url下载文件到本地
1:通过URL下载文件:

public class DownFile { /**  * @param args  * @throws Exception   */ public static void main(String[] args) throws Exception {  String encodedStr = java.net.URLEncoder.encode("我是中文","GBK"); // 有时用UTF-8  download("http://www.baidu.com?args=" + encodedStr,"c:\\ret.html");  download("http://music.yule.sohu.com/upload/zhiqianqiutian.mp3", "C:\\1.mp3"); } public static void download(String urlString,String filename)throws Exception{  URL url = new URL(urlString);  URLConnection con = url.openConnection();  InputStream is = con.getInputStream();    byte[] bs = new byte[1024];  int len;  OutputStream os = new FileOutputStream(filename);  while((len = is.read(bs))!=-1){   os.write(bs, 0, len);  }  os.close();  is.close(); }}

2:缓冲读取URL方法:

package com.rayoo.test;import java.io.BufferedInputStream;import java.io.BufferedOutputStream;import java.io.FileOutputStream;import java.io.InputStream;import java.io.OutputStream;import java.net.URL;import java.net.URLConnection;public class TestDownFile {    public static void main(String[] args) throws Exception {        java.net.URLDecoder.decode(java.net.URLEncoder.encode("我是中文", "GBK"), "GBK");        download("http://music.yule.sohu.com/upload/zhiqianqiutian.mp3", "C:\\1.mp3");    }    public static void download(String urlString, String filename)            throws Exception {        URL url = new URL(urlString);        URLConnection con = url.openConnection();        InputStream is = con.getInputStream();        OutputStream os = new FileOutputStream(filename);        BufferedInputStream bufferInput = new BufferedInputStream(is);        BufferedOutputStream bufferOutput = new BufferedOutputStream(os);        byte[] bs = new byte[1024];        int len = 0;        while ((len = bufferInput.read(bs)) != -1) {            bufferOutput.write(bs, 0, len);        }        bufferOutput.flush();        bufferInput.close();        bufferOutput.close();        os.close();        is.close();    }}

-----------------------

URL url = new URL("http://www.baidu.com");InputStream is = url.openStream();ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();final byte[] bytes = new byte[1024];int read = 0;while ((read = is.read(bytes)) >= 0) {byteArrayOutputStream.write(bytes, 0, read);}File file = new File("c:\\test.txt");if(!file.getParentFile().exists())file.getParentFile().mkdirs();if(!file.exists())file.createNewFile();FileOutputStream fos = new FileOutputStream(file);fos.write(byteArrayOutputStream.toByteArray());is.close();fos.close();