layui后台接收图片的多文件上传并根据时间生成随机名

发布于 2019-07-31  148 次阅读


layui提供了简单的前端上传图片的案例,但很少有后端案例,返回时必须是json的格式并且有code参数layui的接口才不会报异常

package com.action;

import cn.hutool.json.JSONObject;
import com.mysql.jdbc.CharsetMapping;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

@Controller
public class UpLoadAction {

    File tempPathFile;

    private String uploadPath = System.getProperty("ROOT") + "/tmp"; // 上传文件的目录

    @RequestMapping("/upload")
    @ResponseBody
    public JSONObject uploadImage(@RequestParam("file") MultipartFile file) {
        JSONObject res = new JSONObject();
        JSONObject resUrl = new JSONObject();
        if (!file.isEmpty()) {
            Map<String, String> resObj = new HashMap<>(CharsetMapping.MAP_SIZE);
            try {
                //得到旧文件名
                String oldFileName =file.getOriginalFilename();
                //得到后缀名
                int index =oldFileName.lastIndexOf(".");
                String extName =oldFileName.substring(index);
                //新文件名
                String newFileName=System.nanoTime()+extName;
                BufferedOutputStream out = new BufferedOutputStream(
                        new FileOutputStream(new File(uploadPath, newFileName)));
                out.write(file.getBytes());
                out.flush();
                out.close();
            } catch (IOException e) {
                res.put("code", 1);
                res.put("msg", "上传出错");
                res.put("data", resUrl);
                return res;
            }
            res.put("code", 0);
            res.put("msg", "上传成功");
            res.put("data", resUrl);
            return res;
        } else {
            res.put("code", 0);
            res.put("msg", "上传为空");
            res.put("data", resUrl);
            return res;
        }

    }
}

System.nanoTime()方法获取当前时间,以微毫秒为单位

java的UrlDcode解码方式

URLEncode和URLDecode用于完成普通字符串和 application/x-www-from-urlencoded MIME字符串之间的相互转化

如果传递的字符串中包含非西欧字符的字符串,会被转化成%XX%XX XX为十六进制的数字

    try {
                // 将application/x-www-from-urlencoded字符串转换成普通字符串
                String keyWord = URLDecoder.decode("%C4%E3%BA%C3", "GBK");
                System.out.println(keyWord);  //输出你好
                // 将普通字符创转换成application/x-www-from-urlencoded字符串
                String urlString = URLEncoder.encode("你好", "GBK");  //输出%C4%E3%BA%C3

                System.out.println(urlString);
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

今天你恰柠檬了咩