java图片从网络下载到本地

  String picVehicle = obj.getPicVehicle();
            // 根路径加上传参数的路径构成文件路径地址
            String realPath = picVehicle;
            // 文件名编码
            try {
                // 构造URL
                URL url = new URL(realPath);
                // 打开连接
                URLConnection con = url.openConnection();
                //设置请求超时为20s
                con.setConnectTimeout(20 * 1000);
                //文件路径不存在 则创建
                File sf = new File("D:\\picture");
                if (!sf.exists()) {
                    sf.mkdirs();
                }
                //jdk 1.7 新特性自动关闭
                try (InputStream in = con.getInputStream();
                     OutputStream out = new FileOutputStream(sf.getPath() + "\\" + count.get()+".jpg")) {
                    //创建缓冲区
                    byte[] buff = new byte[1024];
                    int n;
                    // 开始读取
                    while ((n = in.read(buff)) >= 0) {
                        out.write(buff, 0, n);
                    }
                    count.getAndIncrement();
                } catch (Exception e) {
                    e.printStackTrace();
                }