java实现下载网络资源至服务器

import cn.hutool.core.io.FileUtil;
import lombok.extern.slf4j.Slf4j;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
 * @desc 文件工具类
 * @com 
 * @Author tanzhiming(Jruoning) 2020/1/2 10:07
 */
@Slf4j
public class FileUtils extends FileUtil {

    /**
     * 下载网络文件至服务器本地
     * @param urlStr 网络路径
     * @param apPath 存储路径+文件名称
     * @return
     */
    public static void downloadFromUrl(String urlStr, String apPath) {
        log.info("开始下载网络文件[{}]至服务器[{}].......", urlStr, apPath);
        URL url = null;
        try {
            url = new URL(urlStr);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        HttpURLConnection conn = null;
        try {
            conn = (HttpURLConnection)url.openConnection();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //设置超时间为3秒
        conn.setConnectTimeout(3 * 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 = null;
        try {
            inputStream = conn.getInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //获取自己数组
        byte[] getData = new byte[0];
        try {
            getData = readInputStream(inputStream);
        } catch (IOException e) {
            e.printStackTrace();
        }
        File file = new File(apPath);
        File parentFile = file.getParentFile();
        if (!parentFile.exists()) {
            FileUtils.mkdir(parentFile);
        }
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            fos.write(getData);
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(fos!=null){
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(inputStream!=null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        log.info("文件下载成功至服务器[{}]", apPath);
    }

    /**
     * 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();
    }
}