java实现从url路径中下载pdf文档到本地

package com.cellstrain.icell.util;

import java.io.*;import java.net.*;

public class DownloadPdf {

/**     * 从网络Url中下载文件     * @param urlStr     * @param fileName     * @param savePath     * @throws IOException     */    public static void  downLoadByUrl(String urlStr,String fileName,String savePath) throws IOException{        URL url = new URL(urlStr);        HttpURLConnection conn = (HttpURLConnection)url.openConnection();        //设置超时间为3秒        conn.setConnectTimeout(5*1000);        //防止屏蔽程序抓取而返回403错误        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");        //得到输入流        InputStream inputStream = conn.getInputStream();        //获取自己数组        byte[] getData = readInputStream(inputStream);        //文件保存位置        File saveDir = new File(savePath);        if(!saveDir.exists()){            saveDir.mkdir();        }        File file = new File(saveDir+File.separator+fileName);        FileOutputStream fos = new FileOutputStream(file);        fos.write(getData);        if(fos!=null){            fos.close();        }        if(inputStream!=null){            inputStream.close();        }        System.out.println("info:"+url+" download success");

}

/**     * 从输入流中获取字节数组     * @param inputStream     * @return     * @throws IOException     */    public static  byte[] readInputStream(InputStream inputStream) throws IOException {        byte[] buffer = new byte[1024];        int len = 0;        ByteArrayOutputStream bos = new ByteArrayOutputStream();        while((len = inputStream.read(buffer)) != -1) {            bos.write(buffer, 0, len);        }        bos.close();        return bos.toByteArray();    }

public static void main(String[] args) {        try{            downLoadByUrl("https://www.mybiosource.com/images/tds/protocol_samples/MBS700_Antibody_Set_Sandwich_ELISA_Protocol.pdf",                    "ELISA.pdf","E:/upload/protocol");        }catch (Exception e) {            // TODO: handle exception        }    }}