FileUtils

io 文件操作

package com.zxwa.ntmss.Excel;

import cn.hutool.core.util.StrUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

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


public class FileUtils {
    private static Logger LOG = LoggerFactory.getLogger(FileUtils.class);



    public static byte[] netImage2Bytes(String netUrl) {
        LOG.info("开始下载：" + netUrl);
        try {
            //new一个URL对象
            URL url = new URL(netUrl);
            //打开链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            //设置请求方式为"GET"
            conn.setRequestMethod("GET");
            //超时响应时间为5秒
            conn.setConnectTimeout(5 * 1000);
            //通过输入流获取图片数据
            InputStream inStream = conn.getInputStream();
            //得到图片的二进制数据，以二进制封装得到数据，具有通用性
            byte[] data = readInputStream(inStream);
////                //new一个文件对象用来保存图片，默认保存当前工程根目录
//                File imageFile = new File("D://BeautyGirl.jpg");
//                //创建输出流
//                FileOutputStream outStream = new FileOutputStream(imageFile);
//                //写入数据
//                outStream.write(data);
//                //关闭输出流
//                outStream.close();
            return data;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

     public static String netImage2File(String netUrl, String fileLocal) throws Exception {
        LOG.info("开始下载：" + netUrl);
        //new一个URL对象
        URL url = new URL(netUrl);
        //打开链接
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        //设置请求方式为"GET"
        conn.setRequestMethod("GET");
        //超时响应时间为5秒
        conn.setConnectTimeout(5 * 1000);
        //通过输入流获取图片数据
        InputStream inStream = conn.getInputStream();
        //得到图片的二进制数据，以二进制封装得到数据，具有通用性
        byte[] data = readInputStream(inStream);
//                //new一个文件对象用来保存图片，默认保存当前工程根目录
        File imageFile = new File(fileLocal);
        //创建输出流
        FileOutputStream outStream = new FileOutputStream(imageFile);
        //写入数据
        outStream.write(data);
        //关闭输出流
        outStream.close();
        return fileLocal;
    }

    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        //创建一个Buffer字符串
        byte[] buffer = new byte[1024];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len = 0;
        //使用一个输入流从buffer里把数据读取出来
        while ((len = inStream.read(buffer)) != -1) {
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
        }
        //关闭输入流
        inStream.close();
        //把outStream里的数据写入内存
        return outStream.toByteArray();
    }


    public static byte[] readInputStream(String filePath) throws Exception {
        File file = new File(filePath);
        FileInputStream fis = new FileInputStream(file);
        return readInputStream(fis);
    }
}