Springboot导出Excel并下载

Posted 2022-11-18 createsequence

引入相关依赖

<!--数据导出excel-->
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.poi/poi-ooxml-schemas -->
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml-schemas</artifactId>
    <version>3.17</version>
</dependency>

Controller

package com.huang.controller;

import com.huang.mapper.UsersMapper;
import com.huang.util.excelExport.ExcelExport2;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * @Author：huang
 * @Date：2019-09-21 13:13
 * @Description：<描述>
 */
@Controller
public class TestController 

    @Resource
    private UsersMapper usersMapper;

    @RequestMapping("/test")
    public void testExprotExcel(HttpServletResponse response)

        String[] arr = new String[]"ID","用户名","账号","密码","备注";

        ExcelExport2.export(response,usersMapper.selectAll(),arr);

    

工具类

文件导出excel工具类

package com.huang.util.excelExport;

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

/**
 * @Author：haung
 * @Date：2019-09-21 11:21
 * @Description：Excel导出工具类，依赖于ClassUtil工具类
 */
public final class ExcelExport2 

    /**
     * 将传入的数据导出excel表并下载
     * @param response 返回的HttpServletResponse
     * @param importlist 要导出的对象的集合
     * @param attributeNames 含有每个对象属性在excel表中对应的标题字符串的数组（请按对象中属性排序调整字符串在数组中的位置）
     */
    public static void export(HttpServletResponse response, List<?> importlist, String[] attributeNames) 
        //获取数据集
        List<?> datalist = importlist;

        //声明一个工作薄
        HSSFWorkbook workbook = new HSSFWorkbook();
        //生成一个表格
        HSSFSheet sheet = workbook.createSheet();
        //设置表格默认列宽度为15个字节
        sheet.setDefaultColumnWidth((short) 18);

        //获取字段名数组
        String[] tableAttributeName = attributeNames;
        //获取对象属性
        Field[] fields = ClassUtil.getClassAttribute(importlist.get(0));
        //获取对象get方法
        List<Method> methodList = ClassUtil.getMethodGet(importlist.get(0));

        //循环字段名数组，创建标题行
        Row row = sheet.createRow(0);
        for (int j = 0; j< tableAttributeName.length; j++)
            //创建列
            Cell cell = row.createCell(j);
            //设置单元类型为String
            cell.setCellType(CellType.STRING);
            cell.setCellValue(transCellType(tableAttributeName[j]));
        
        //创建普通行
        for (int i = 0;i<datalist.size();i++)
            //因为第一行已经用于创建标题行，故从第二行开始创建
            row = sheet.createRow(i+1);
            //如果是第一行就让其为标题行
            Object targetObj = datalist.get(i);
            for (int j = 0;j<fields.length;j++)
                //创建列
                Cell cell = row.createCell(j);
                cell.setCellType(CellType.STRING);
                //
                try 
                    Object value = methodList.get(j).invoke(targetObj, new Object[]);
                    cell.setCellValue(transCellType(value));
                 catch (IllegalAccessException e) 
                    e.printStackTrace();
                 catch (InvocationTargetException e) 
                    e.printStackTrace();
                
            
        
        response.setContentType("application/octet-stream");
        //默认Excel名称
        response.setHeader("Content-Disposition", "attachment;fileName="+"test.xls");

        try 
            response.flushBuffer();
            workbook.write(response.getOutputStream());
         catch (IOException e) 
            e.printStackTrace();
        

    

    private static String transCellType(Object value)
        String str = null;
        if (value instanceof Date)
            Date date = (Date) value;
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            str = sdf.format(date);
        else
            str = String.valueOf(value);
            if (str == "null")
                str = "";
            
        

        return str;
    

类操作工具类

package com.huang.util.excelExport;

import org.springframework.stereotype.Component;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

/**
 * @Author：huang
 * @Date：2019-09-21 13:41
 * @Description：关于类的操作的工具类
 */
public final class ClassUtil 

    private ClassUtil() 
        throw new Error("工具类不允许实例化！");
    

    /**
     * 获取类属性
     * @param targetObj 要获取属性的类
     * @return 含有类属性的集合
     */
    public static Field[] getClassAttribute(Object targetObj)

        Class<?> objectClass = targetObj.getClass();
        return objectClass.getDeclaredFields();

    

    /**
     * 获取对象的所有get或set方法
     * @param targetObj 要获取属性的类
     * @param methodKeyword get或者set关键字
     * @return 含有类get或set方法的集合
     */
    public static List<Method> getMethod(Object targetObj,String methodKeyword)
        List<Method> methodList = new ArrayList<>();

        Class<?> objectClass = targetObj.getClass();

        Field[] field = objectClass.getDeclaredFields();
        for (int i = 0;i<field.length;i++)
            //获取属性名并组装方法名
            String fieldName = field[i].getName();
            String getMethodName = methodKeyword
                + fieldName.substring(0, 1).toUpperCase()
                + fieldName.substring(1);

            try 
                Method method = objectClass.getMethod(getMethodName,new Class[]);
                methodList.add(method);
             catch (NoSuchMethodException e) 
                e.printStackTrace();
            
        
        return methodList;
    

    /**
     * 获取对象的所有get方法
     * @param targetObj 要获取属性的类
     * @return 含有类方法的集合
     */
    public static List<Method> getMethodGet(Object targetObj)
        return getMethod(targetObj,"get");
    

    /**
     * 获取对象的所有set方法
     * @param targetObj 要获取属性的类
     * @return 含有类方法的集合
     */
    public static List<Method> getMethodSet(Object targetObj)
        return getMethod(targetObj,"set");