通过 HttpClient 下载 文件

用HttpClient下载文件主要还是文件流的转化的东西比较烦一点。httpclient的东西比较简单的 

引用

需要有的Jar; 
    * commons-httpclient-3.1.jar 
    * commons-logging-1.04.jar 
    * commons-codec-1.3.jar 

public class HttpClientTest {
	
	private final static String REMOTE_FILE_URL = "http://www.gjt.org/download/time/java/tar/javatar-2.5.tar.gz";
	
	private final static int BUFFER = 1024;

	public static void main(String[] args) {

	   HttpClient client = new HttpClient();
	   GetMethod httpGet = new GetMethod(REMOTE_FILE_URL);
		try {
			client.executeMethod(httpGet);
			
			InputStream in = httpGet.getResponseBodyAsStream();
		   
			FileOutputStream out = new FileOutputStream(new File("E:\\test_jar\\javatar-2.5.tar.gz"));
		   
		    byte[] b = new byte[BUFFER];
		    int len = 0;
			while((len=in.read(b))!= -1){
			    out.write(b,0,len);
			}
			in.close();
			out.close();
			
		}catch (HttpException e){
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally{
			httpGet.releaseConnection();
		}
       	System.out.println("download, success!!");
       }
}

这个文章主要是参考自 
http://www.hr.utah.edu/blog/2006/03/03/file-download-using-jakarta-commons-httpclient/ 
使用了缓冲，避免了IO的频繁读写。 

还有一篇 http://weifly.iteye.com/blog/145457 
直接使用byte[]数组，比较便捷，但是没有使用缓冲，因为频繁的读写，看下来下载速度很慢。 

需要的jar包：

• httpClientTest.zip (349.1 KB)