Springboot利用poi导出excel下载

Posted 2022-03-08 n031

Springboot利用poi导出excel下载

因为项目中之前的做法是用反射获取属性，所以demo中也是用的反射，我看网上很多文章都是存入一个List中，不知道这两种哪种更何合适一点，或者有什么更好的方法也请大佬们赐教。

pom

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.13</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.13</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

Service

import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.List;
@Service
public class StudentService 

    public List<Student> getList(Student student, int index, int size) 
        Student student1 = new Student("张三", 90, 18);
        Student student2 = new Student("李四", 85, 17);
        Student student3 = new Student("王五", 70, 19);
        List<Student> list = new ArrayList<>();
        list.add(student1);
        list.add(student2);
        list.add(student3);
        return list;
    

Controller

import lombok.Cleanup;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.List;

@RestController
public class StudentController 

    @Autowired
    public StudentService studentService;

    @RequestMapping("/exportStudentExcel")
    public ResponseEntity<byte[]> exportExcel(Student student) 

        List<Student> list = studentService.getList(student, 0, 10); // 每次只需要改这几行

        String fileName = "学生成绩统计表"; // 每次只需要改这几行
        String[] getters = "getName", "getScore", "getAge"; // 每次只需要改这几行
        String[] headers = "姓名", "分数", "年龄"; // 每次只需要改这几行

        Workbook wb = ExcelUtils.createWorkBook(list, getters, headers,student.getClass()); // 每次只需要改这几行

        @Cleanup ByteArrayOutputStream os = new ByteArrayOutputStream();
        try 
            wb.write(os);
         catch (IOException e) 
            e.printStackTrace();
        
        byte[] content = os.toByteArray();
        HttpHeaders httpHeaders = new HttpHeaders();
        try 
            fileName = URLEncoder.encode(fileName, "UTF-8");
         catch (UnsupportedEncodingException e) 
            e.printStackTrace();
        
        httpHeaders.setContentDispositionFormData("attachment", fileName + ".xlsx");
        return new ResponseEntity<byte[]>(content, httpHeaders, HttpStatus.OK);
    

ExcelUtils

public class ExcelUtils 
    /**
     * 创建excel文档
     *
     * @param getters list中map的key数组集合
     * @param headers excel的列名
     */
    public static Workbook createWorkBook(List list, String[] getters, String[] headers, Class clazz) 

        List<Method> methods = getMethodsByStrs(getters, clazz);

        // 创建.xlsx工作簿
        Workbook wb = new XSSFWorkbook();
        // 创建第一个sheet（页），并命名
        Sheet sheet = wb.createSheet("sheet1");
        // 手动设置列宽.第一个参数表示要为第几列设,第二个参数表示列的宽度,n为列高的像素数.

        for (int i = 0; i < getters.length; i++) 
            sheet.setColumnWidth((short) i, (short) (35.7 * 200));
        

        // 创建第一行
        Row header = sheet.createRow(0);

        // 创建两种单元格格式
        CellStyle cellStyle1 = wb.createCellStyle();
        CellStyle cellStyle2 = wb.createCellStyle();

        // 创建两种字体
        Font font1 = wb.createFont(); // 标题字体
        Font font2 = wb.createFont(); // 正文字体

        // 标题加粗
        font1.setBoldweight(Font.BOLDWEIGHT_BOLD);

        // 设置两种单元格的样式
        setCellStype(cellStyle1, font1);
        setCellStype(cellStyle2, font2);

        //设置header
        for (int i = 0; i < headers.length; i++) 
            Cell cell = header.createCell(i);
            cell.setCellValue(headers[i]);
            cell.setCellStyle(cellStyle1);
        

        //设置data
        int headersNum = 1;
        for (int i = 0; i < list.size(); i++) 
            Row row = sheet.createRow(i + headersNum);
            for (int j = 0; j < methods.size(); j++) 
                try 
                    Object invoke = methods.get(j).invoke(list.get(i));
                    if (invoke != null) 
                        row.createCell(j).setCellValue(invoke.toString());
                    
                 catch (Exception e) 
                    e.printStackTrace();
                
            
        
        return wb;
    

    private static void setCellStype(CellStyle cellStyle, Font font) 
        font.setFontHeightInPoints((short) 10);
        font.setColor(IndexedColors.BLACK.getIndex());
        cellStyle.setFont(font);
        cellStyle.setBorderLeft(CellStyle.BORDER_THIN);
        cellStyle.setBorderRight(CellStyle.BORDER_THIN);
        cellStyle.setBorderTop(CellStyle.BORDER_THIN);
        cellStyle.setBorderBottom(CellStyle.BORDER_THIN);
        cellStyle.setAlignment(CellStyle.ALIGN_CENTER);
    

    private static List<Method> getMethodsByStrs(String[] getters, Class clazz) 
        List<Method> list = new ArrayList<>();
        for (String getter : getters) 
            try 
                list.add(clazz.getDeclaredMethod(getter));
             catch (NoSuchMethodException e) 
                e.printStackTrace();
            
        
        return list;