pring-boot匯出excel

本文使用Apache POL實現excel文件的匯出

pom.xml 新增Apache POL依賴

<dependency>  
    <groupId>org.apache.poi</groupId>  
    <artifactId>poi</artifactId>  
    <version>3.14</version>  
</dependency>  

匯出excel

匯出excel比較重要的api有以下幾個，其他的並無難點

• 建立一個excel檔案工作薄；（HSSFWorkbook workbook = new HSSFWorkbook()）
• 建立一張表；HSSFSheet sheet = workbook.createSheet("統計表")
• 建立一行；HSSFRow row = sheet.createRow(0)
• 填充一列資料; row.createCell(0).setCellValue("資料")
• 設定一個單元格樣式；cell.setCellStyle(style)

• package com.example.demo.controller;
  
  import com.example.demo.domain.User;
  import com.example.demo.service.UserService;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.web.bind.annotation.*;
  
  import org.apache.poi.hssf.usermodel.HSSFCell;
  import org.apache.poi.hssf.usermodel.HSSFCellStyle;
  import org.apache.poi.hssf.usermodel.HSSFDataFormat;
  import org.apache.poi.hssf.usermodel.HSSFFont;
  import org.apache.poi.hssf.usermodel.HSSFRow;
  import org.apache.poi.hssf.usermodel.HSSFSheet;
  import org.apache.poi.hssf.usermodel.HSSFWorkbook;
  
  import javax.servlet.http.HttpServletResponse;
  import java.io.FileOutputStream;
  import java.io.OutputStream;
  import java.net.URLEncoder;
  import java.util.List;
  
  @RestController
  @RequestMapping(value = "/excel")
  public class ExcelController {
  
      @Autowired
      private UserService userService;
  
      //建立表頭
      private void createTitle(HSSFWorkbook workbook,HSSFSheet sheet){
          HSSFRow row = sheet.createRow(0);
          //設定列寬，setColumnWidth的第二個引數要乘以256，這個引數的單位是1/256個字元寬度
          sheet.setColumnWidth(1,12*256);
          sheet.setColumnWidth(3,17*256);
  
          //設定為居中加粗
          HSSFCellStyle style = workbook.createCellStyle();
          HSSFFont font = workbook.createFont();
          font.setBold(true);
          style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
          style.setFont(font);
  
          HSSFCell cell;
          cell = row.createCell(0);
          cell.setCellValue("ID");
          cell.setCellStyle(style);
  
  
          cell = row.createCell(1);
          cell.setCellValue("顯示名");
          cell.setCellStyle(style);
  
          cell = row.createCell(2);
          cell.setCellValue("使用者名稱");
          cell.setCellStyle(style);
  
          cell = row.createCell(3);
          cell.setCellValue("建立時間");
          cell.setCellStyle(style);
      }
  
      //生成user表excel
      @GetMapping(value = "/getUser")
      public String getUser(HttpServletResponse response) throws Exception{
          HSSFWorkbook workbook = new HSSFWorkbook();
          HSSFSheet sheet = workbook.createSheet("統計表");
          createTitle(workbook,sheet);
          List<User> rows = userService.getAll();
  
          //設定日期格式
          HSSFCellStyle style = workbook.createCellStyle();
          style.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
  
          //新增資料行，並且設定單元格資料
          int rowNum=1;
          for(User user:rows){
              HSSFRow row = sheet.createRow(rowNum);
              row.createCell(0).setCellValue(user.getId());
              row.createCell(1).setCellValue(user.getName());
              row.createCell(2).setCellValue(user.getUsername());
              HSSFCell cell = row.createCell(3);
              cell.setCellValue(user.getCreate_time());
              cell.setCellStyle(style);
              rowNum++;
          }
  
          String fileName = "匯出excel例子.xls";
  
          //生成excel檔案
          buildExcelFile(fileName, workbook);
  
          //瀏覽器下載excel
          buildExcelDocument(fileName,workbook,response);
  
          return "download excel";
      }
  
      //生成excel檔案
      protected void buildExcelFile(String filename,HSSFWorkbook workbook) throws Exception{
          FileOutputStream fos = new FileOutputStream(filename);
          workbook.write(fos);
          fos.flush();
          fos.close();
      }
  
      //瀏覽器下載excel
      protected void buildExcelDocument(String filename,HSSFWorkbook workbook,HttpServletResponse response) throws Exception{
          response.setContentType("application/vnd.ms-excel");
          response.setHeader("Content-Disposition", "attachment;filename="+URLEncoder.encode(filename, "utf-8"));
          OutputStream outputStream = response.getOutputStream();
          workbook.write(outputStream);
          outputStream.flush();
          outputStream.close();
      }
  
  
  }