Java中的IO流-从网上下载图片

IO流中从网上下载图片：

public class Demo{	
	public static void testDownLoad(){ 
		BufferedInputStream bis =null; 
		BufferedOutputStream bos=null; 
		String HTTP_URL=“         ”;    	//图片地址 
		
	
		try { 
			int contentLength = getConnection(HTTP_URL).getContentLength();
		System.out.println("文件的大小是:"+contentLength);
		if (contentLength>32) { 
			InputStream is= getConnection(HTTP_URL).getInputStream(); 
			bis = new BufferedInputStream(is);
			FileOutputStream fos = new FileOutputStream("      "); 
			bos= new BufferedOutputStream(fos); 
			int b = 0; byte[] byArr = new byte[1024]; 
			while((b= bis.read(byArr))!=-1){ 
				bos.write(byArr, 0, b);
				} System.out.println("下载的文件的大小是------:"+contentLength);
				} 
		} catch (Exception e) { 
			e.printStackTrace();
			}finally{ 
				try {
					if(bis !=null){ bis.close();
					} if(bos !=null){ bos.close(); 
					} 
					} catch (IOException e) {
						e.printStackTrace(); 
						}
				}
			}
	
	
	public static HttpURLConnection getConnection(String httpUrl) throws 
	                                                             Exception { 
	URL url = new URL(httpUrl); 
	HttpURLConnection connection = (HttpURLConnection) url.openConnection(); 
	connection.setRequestMethod("GET");
	connection.setRequestProperty("Content-Type", "application/octet-stream");
	connection.setDoOutput(true); connection.setDoInput(true);
	connection.setRequestProperty("Connection", "Keep-Alive"); 
	connection.connect(); return connection;
	}
	
	public static void main(String[] args) {
		testDownLoad();
	}

}