Excel导入并读入数据库

src/main/java/com/we/controller/ExcelController.java

+package com.we.controller;
+import	java.net.URLEncoder;
+
+import com.alibaba.excel.EasyExcel;
+import com.we.pojo.Student;
+import com.we.service.IStudentService;
+import com.we.service.impl.StudentServiceImpl;
+import com.we.util.UploadDataListener;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.multipart.MultipartFile;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.util.List;
+
+@Controller
+public class ExcelController {
+
+    private String prefix = "/excelop";
+
+    @Autowired
+    private IStudentService studentService;
+    @Autowired
+    private StudentServiceImpl studentServiceImpl;
+
+
+    @GetMapping("/excel")
+    public String excel() {
+        return prefix + "/excel";
+    }
+
+    /**
+     * 导出Excel
+     */
+    @RequestMapping("/exportExcel")
+    public String exportExcel() {
+        List stuList = studentService.selectStuList();
+        String path = "F:/Desktop/";
+        String fileName = path + "学生信息表格" + System.currentTimeMillis() + ".xlsx";
+        EasyExcel.write(fileName, Student.class).sheet("学生信息表格").doWrite(stuList);
+        return prefix + "/exportExcel";
+    }
+
+    /**
+     * 下载Excel
+     *
+     * @param response
+     */
+    @RequestMapping("/downloadExcel")
+    public void downloadExcel(HttpServletResponse response) throws IOException {
+        List stuList = studentService.selectStuList();
+        response.setContentType("application/vnd.ms-excel");
+        response.setCharacterEncoding("utf-8");
+        // 这里URLEncoder.encode可以防止中文乱码
+        String fileName = URLEncoder.encode("学生信息表下载", "UTF-8");
+        response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
+        EasyExcel.write(response.getOutputStream(), Student.class).sheet("学生信息").doWrite(stuList);
+    }
+
+    /**
+     * Excel导入
+     * @param file
+     * @return
+     * @throws IOException
+     */
+    @PostMapping("/uploadExcel")
+    @ResponseBody
+    public String uploadExcel(@RequestParam("fileName")MultipartFile file) throws IOException {
+        EasyExcel.read(file.getInputStream(), Student.class, new UploadDataListener(studentServiceImpl)).sheet().doRead();
+        return "success";
+    }
+
+}

src/main/java/com/we/controller/MysqlTestController.java

@@ -6,9 +6,6 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
 import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.PostMapping;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.ResponseBody;
 
 import java.util.List;
 

src/main/java/com/we/mapper/StudentMapper.java

@@ -9,4 +9,6 @@ import java.util.List;
 public interface StudentMapper {
 
     public List<Student> selectStuList();
+
+    public int insertStuList(List<Student> list);
 }

src/main/java/com/we/pojo/Student.java

 package com.we.pojo;
 
+import com.alibaba.excel.annotation.ExcelProperty;
+import com.alibaba.excel.metadata.BaseRowModel;
+import lombok.Data;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.ToString;
 
+@Data
 @Getter
 @Setter
 @ToString
-public class Student {
+public class Student extends BaseRowModel {
+    @ExcelProperty(value = "学号", index = 0)
     private String stuid;
+    @ExcelProperty(value = "班级", index = 1)
     private String stuclass;
+    @ExcelProperty(value = "姓名", index = 2)
     private String stuname;
+    @ExcelProperty(value = "年龄", index = 3)
     private String stuage;
+    @ExcelProperty(value = "性别", index = 4)
     private String stusex;
+    @ExcelProperty(value = "电话", index = 5)
     private String stutel;
 
 }

src/main/java/com/we/service/IStudentService.java

@@ -7,4 +7,6 @@ import java.util.List;
 public interface IStudentService {
 
     public List<Student> selectStuList();
+
+    public int insertStuList(List<Student> list);
 }

src/main/java/com/we/service/impl/StudentServiceImpl.java

@@ -18,4 +18,10 @@ public class StudentServiceImpl implements IStudentService {
     public List<Student> selectStuList() {
         return studentMapper.selectStuList();
     }
+
+    @Override
+    public int insertStuList(List<Student> list) {
+        int flag = studentMapper.insertStuList(list);
+        return flag;
+    }
 }

src/main/java/com/we/util/UploadDataListener.java

+package com.we.util;
+
+import com.alibaba.excel.context.AnalysisContext;
+import com.alibaba.excel.event.AnalysisEventListener;
+import com.we.pojo.Student;
+import com.we.service.impl.StudentServiceImpl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Excel读取监听
+ */
+public class UploadDataListener extends AnalysisEventListener<Student> {
+
+    // 每隔5条存储数据库，实际使用中可以3000条，然后清理list ，方便内存回收
+    private static final int BATCH_COUNT = 5;
+    List<Student> list = new ArrayList<Student>();
+
+    private StudentServiceImpl studentServiceImpl;
+
+    public UploadDataListener() {
+        // 这里是demo，所以随便new一个。实际使用如果到了spring,请使用下面的有参构造函数
+        studentServiceImpl = new StudentServiceImpl();
+    }
+
+    /**
+     * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来
+     *
+     * @param studentServiceImpl
+     */
+    public UploadDataListener(StudentServiceImpl studentServiceImpl) {
+        this.studentServiceImpl = studentServiceImpl;
+    }
+
+    @Override
+    public void invoke(Student data, AnalysisContext context) {
+        list.add(data);
+        // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
+        if (list.size() >= BATCH_COUNT) {
+            saveData();
+            // 存储完成清理 list
+            list.clear();
+        }
+    }
+
+    @Override
+    public void doAfterAllAnalysed(AnalysisContext context) {
+        // 这里也要保存数据，确保最后遗留的数据也存储到数据库
+        saveData();
+    }
+
+    /**
+     * 加上存储数据库
+     */
+    private void saveData() {
+        studentServiceImpl.insertStuList(list);
+    }
+}

src/main/resources/mapper/StudentMapper.xml

@@ -29,4 +29,13 @@
         </where>
     </select>
 
+    <insert id="insertStuList">
+        insert into student
+        (stuid, stuclass, stuname, stuage, stusex, stutel)
+        values
+        <foreach collection="list" item="stulist" separator=",">
+            (#{stulist.stuid}, #{stulist.stuclass}, #{stulist.stuname}, #{stulist.stuage}, #{stulist.stusex}, #{stulist.stutel})
+        </foreach>
+    </insert>
+
 </mapper>
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src/main/resources/mybatis/mybatis-config.xml

+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE configuration
+        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
+        "http://mybatis.org/dtd/mybatis-3-config.dtd">
+<configuration>
+
+    <settings>
+        <setting name="cacheEnabled"             value="true" />  <!-- 全局映射器启用缓存 -->
+        <setting name="useGeneratedKeys"         value="true" />  <!-- 允许 JDBC 支持自动生成主键 -->
+        <setting name="defaultExecutorType"      value="REUSE" /> <!-- 配置默认的执行器 -->
+        <setting name="logImpl"                  value="SLF4J" /> <!-- 指定 MyBatis 所用日志的具体实现 -->
+        <!-- <setting name="mapUnderscoreToCamelCase" value="true"/>  驼峰式命名 -->
+    </settings>
+
+</configuration>
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src/main/resources/templates/excelop/excel.html

+<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" xmlns:th="http://www.thymeleaf.org">
+<head>
+    <meta charset="UTF-8">
+    <title>导入导出</title>
+</head>
+<body>
+<a href="#" th:href="@{/exportExcel}">导出Excel</a><br/>
+<a href="#" th:href="@{/downloadExcel}">下载Excel</a>
+<form action="uploadExcel" method="post" enctype="multipart/form-data">
+    <input type="file" name="fileName"/>
+    <input type="submit"/>
+</form>
+</body>
+</html>
\ No newline at end of file

src/main/resources/templates/excelop/exportExcel.html

+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>导出成功</title>
+</head>
+<body>
+导出成功！
+</body>
+</html>
\ No newline at end of file