java 下載遠程文件到本地

    /**
     * 下載遠程文件到本地
     * @param urlStr
     * @param fileName
     * @param savePath
     * @return
     * @throws IOException
     */
    public static File testIO(String urlStr, String fileName, String savePath) throws IOException {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        //設置超時間爲5秒
        conn.setConnectTimeout(5*1000);
        //防止屏蔽程序抓取而返回403錯誤
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
        //得到輸入流
        InputStream inputStream = conn.getInputStream();
        //創建保存路徑
        File saveDir = new File(savePath);
        if(!saveDir.exists()) {
            saveDir.mkdir();
        }
        //創建文件
        File file = new File(saveDir+File.separator+fileName);
        //文件輸出流
        FileOutputStream fout = new FileOutputStream(file);
        //輸出文件
        byte[] buff = new byte[4096];
        int len = -1;
        while ((len = inputStream.read(buff)) != -1) {
            fout.write(buff,0,len);
        }
        //關閉輸出輸入流
        fout.close();
        inputStream.close();
        System.out.println("info:"+url+" download success");
        return file;
    }