springboot+layui：多文件上传到本地

html页面代码

直接复制layui官方文档代码

<div class="layui-upload">
    <button class="layui-btn layui-btn-normal" id="testList" type="button">选择文件button>
    <div class="layui-upload-list">
        <table class="layui-table">
            <thead>
            <tr><th>文件名th>
                <th>大小th>
                <th>状态th>
                <th>操作th>
            tr>thead>
            <tbody id="demoList">tbody>
        table>
    div>
    <button class="layui-btn" id="testListAction" type="button">开始上传button>
div>

js代码

直接在官方文档复制的代码的基础上修改

<script>
    var files=[];
    //JavaScript代码区域
    layui.use(['element','upload'], function(){
     
        var $ = layui.jquery
            ,upload = layui.upload;

        //上传
        //多文件列表示例
        var demoListView = $('#demoList')
            ,uploadListIns = upload.render({
     
            elem: '#testList'
            ,url: '/data/uploadSource' //改成您自己的上传接口
            ,accept: 'file'
            ,exts: 'txt|rar|zip|doc|docx|pdf|xls|xlsx' //允许上传的文件类型
            ,multiple: true
            ,auto: false
            ,bindAction: '#testListAction'
            ,choose: function(obj){
     
                var files = this.files = obj.pushFile(); //将每次选择的文件追加到文件队列
                //读取本地文件
                obj.preview(function(index, file, result){
     
                    var tr = $(['+ index +'">'
                        ,''+ file.name +''
                        ,''+ (file.size/1024).toFixed(1) +'kb'
                        ,'等待上传'
                        ,''
                        ,'重传'
                        ,'删除'
                        ,''
                        ,''].join(''));

                    //单个重传
                    tr.find('.demo-reload').on('click', function(){
     
                        obj.upload(index, file);
                    });

                    //删除
                    tr.find('.demo-delete').on('click', function(){
     
                        delete files[index]; //删除对应的文件
                        tr.remove();
                        uploadListIns.config.elem.next()[0].value = ''; //清空 input file 值，以免删除后出现同名文件不可选
                    });

                    demoListView.append(tr);
                });
            }
            ,done: function(res, index, upload){
     
                if (res.code == 0){
     
                    files.push({
     "fileName":res.filename,"fileUrl":res.fileUrl,"fileSize":res.fileSize});//,"fileUrl":res.fileUrl
                    var json = JSON.stringify(files);
                    //将上传的文件信息加入到集合中并转换成json字符串
                    $("#fileJson").attr("value",json);

                    var fileUrl = res.fileUrl;
                    var tr = demoListView.find('tr#upload-'+ index)
                        ,tds = tr.children();
                    tds.eq(2).html('上传成功');
                    tds.eq(3).html(''+fileUrl+'');
                    tds.eq(4).html(''); //清空操作
                    return delete this.files[index]; //删除文件队列已经上传成功的文件
                }
                this.error(index, upload);
            }
            ,error: function(index, upload){
     
                var tr = demoListView.find('tr#upload-'+ index)
                    ,tds = tr.children();
                tds.eq(2).html('上传失败');
                tds.eq(3).find('.demo-reload').removeClass('layui-hide'); //显示重传
            }
        });
 });

</script>

后台controller代码

package com.example.demo1.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @author dy
 * @version 1.0
 * @date 2020/2/27 15:47
 */

@Controller
@RequestMapping(value = "/data")
public class DataController {
     

    @RequestMapping(value="/uploadSource" , method = RequestMethod.POST)
    @ResponseBody
    public String uploadSource(@RequestParam("file") MultipartFile file) {
     
        System.out.println(file);
        String pathString = null;
        if(file!=null) {
     
        //获取上传的文件名称
        String filename = file.getOriginalFilename();
        //文件上传时，chrome与IE/Edge对于originalFilename处理方式不同
        //chrome会获取到该文件的直接文件名称，IE/Edge会获取到文件上传时完整路径/文件名
        //Check for Unix-style path
        int unixSep = filename.lastIndexOf('/');
        //Check for Windows-style path
        int winSep = filename.lastIndexOf('\\');
        //cut off at latest possible point
        int pos = (winSep > unixSep ? winSep:unixSep);
        if (pos != -1)
            filename = filename.substring(pos + 1);
            pathString = "E:/upload/" + new SimpleDateFormat("yyyyMMddHHmmss").format(new Date()) + "_" +filename;//上传到本地
        }
        try {
     
            File files=new File(pathString);//在内存中创建File文件映射对象
            //打印查看上传路径
            System.out.println(pathString);
            if(!files.getParentFile().exists()){
     //判断映射文件的父文件是否真实存在
                files.getParentFile().mkdirs();//创建所有父文件夹
            }
            file.transferTo(files);//采用file.transferTo 来保存上传的文件
        } catch (Exception e) {
     
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "{\"code\":0, \"msg\":\"success\", \"fileUrl\":\"" + pathString + "\"}";
    }
}

上传成功显示页面

遇到的问题

• 请求上传接口异常 - FileNotFoundException
• org.apache.tomcat.util.http.fileupload.impl.FileSizeLimitExceededException: The field file exceeds its maximum permitted size of 1048576 bytes.
• 返回值问题
  layui官方代码要求返回的json格式

{
     
  "code": 0
  ,"msg": ""
  ,"data": {
     
    "src": "http://cdn.layui.com/123.jpg"
  }
}