Java常用代码

1. 下载网络图片

public void download(String strUrl, String filename){
    try{
        URL url = new URL(strUrl);
        HttpURLConnection  conn = (HttpURLConnection) url.openConnection();
        conn.setConnectTimeout(5*1000);  
        conn.connect();
        InputStream in = conn.getInputStream();
        
        OutputStream out = new FileOutputStream(new File(filename));
        
        byte[] buf = new byte[1024];
        int len = 0;
        while((len = in.read(buf)) != -1){
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
        System.out.println(filename + "下载成功");
    }catch(Exception e){
        System.out.println(filename + "下载失败");
    }
}