Android从服务器下载文件并存储

public void Download(final String path){
        //将用户信息传入服务器
        new Thread(){
            @Override
            public void run() {
                super.run();
                try {
                    URL url = new URL(path);
                    HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
                    httpURLConnection.setConnectTimeout(5000);//推荐设置网络延时
                    httpURLConnection.setReadTimeout(5000);//设置从主机读取数据超时（单位：毫秒）
                    httpURLConnection.setRequestMethod("GET");
                    httpURLConnection.setDoInput(true);
                    httpURLConnection.connect(); //此处必须显式进行连接

                    //以下同Post
                    //获取响应的状态码，判断是否请求成功

                    if(httpURLConnection.getResponseCode()==HttpURLConnection.HTTP_OK){

                        //获得网络字节输入流对象
                        InputStream is=httpURLConnection.getInputStream();// 不是操作文件的吗
                        //建立内存到硬盘的连接
                        System.out.println("111");
                        FileOutputStream fos=new FileOutputStream(new File(Environment.getExternalStorageDirectory() + "/Pictures/ss.jpg"));
                        System.out.println("222");
                        //老三样 写文件
                        byte[] b=new byte[4 * 1024];
                        int len=0;
                        while((len=is.read(b))!=-1){  //先读到内存
                            fos.write(b, 0, len);
                        }
                        System.out.println("下载成功");
                        fos.flush();
                        fos.close();
                    }
                }catch (IOException ioe){
                }
            }
        }.start();
    }

记得Android6.0需要动态申请读写sd卡权限。权限申请可参考https://blog.csdn.net/qq_38367681/article/details/103794429