poi excel download

package com.leinovo.qes.portal.modules.report.controller;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.apache.poi.hssf.util.HSSFColor;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.VerticalAlignment;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.List;


/**
 * @description: ExcelController
 * @author: leiming5
 * @date: 2020-10-28 17:35
 */
@Api(tags = "Excel Download 接口")
@RestController
public class ExcelController {
    
    
    
    /**
     * EXCEL 生成，然后，下载
     *
     * @param response 响应对象
     * @author: leiming5
     */
    @ApiOperation("report/download")
    @GetMapping("report/download")
    public void test22(HttpServletResponse response) {
    
    

        String fileName = "template.XLSX";
        response.setHeader("content-disposition", "attachment;filename=" + fileName);

        try (OutputStream out = response.getOutputStream()) {
    
    

            Workbook workbook = new XSSFWorkbook();

            //生成一个表格
            Sheet sheet = workbook.createSheet("模板Excel");

            // 获取表格数据
            List<List<String>> excelHead = generateHead();
            List<List<Object>> excelData = generateData();

            createExcel(sheet, excelHead, excelData, workbook);

            workbook.write(out);

        } catch (FileNotFoundException e) {
    
    
            e.printStackTrace();
        } catch (IOException e) {
    
    
            e.printStackTrace();
        }
    }

    /**
     * 将表头和数据一起写入excel,并设置样式
     *
     * @param sheet     表格
     * @param excelHead 表头数据
     * @param excelData 表个数据
     * @param workbook  当前工作簿
     * @author: leiming5
     */
    private void createExcel(Sheet sheet, List<List<String>> excelHead, List<List<Object>> excelData, Workbook workbook) {
    
    

        // 放入表头字段
        for (int i = 0; i < excelHead.size(); i++) {
    
    

            Row row = sheet.createRow(i);
            List<String> list = excelHead.get(i);

            for (int j = 0; j < list.size(); j++) {
    
    

                Cell cell = row.createCell(j);

                cell.setCellValue(list.get(j));
                cell.setCellStyle(getCellStyle(workbook, "head"));

                if (i == 1) {
    
    
//                    sheet.autoSizeColumn(j); // 设置自适应列宽
                    sheet.setColumnWidth(j, 18 * 256);
                }
            }
        }

        // 合并标题行
        CellRangeAddress range = new CellRangeAddress(0, 0, 0, excelHead.get(1).size() - 1);
        sheet.addMergedRegion(range);
        // 设置列宽
//        sheet.setDefaultColumnWidth(18); // 设置默认列宽
        sheet.setColumnWidth(0, 26 * 256);
        sheet.setColumnWidth(1, 26 * 256);

        // 放入数据
        for (int i = 0; i < excelData.size(); i++) {
    
    

            Row row = sheet.createRow(i + excelHead.size());
            List<Object> list = excelData.get(i);

            for (int j = 0; j < list.size(); j++) {
    
    

                Cell cell = row.createCell(j);
                Object o = list.get(j);

                String str = String.valueOf(o);
                if (isNumeric(str)) {
    
    
                    cell.setCellValue(Double.parseDouble(str));
                } else {
    
    
                    cell.setCellValue(str);
                }
                cell.setCellStyle(getCellStyle(workbook, "body"));
            }
        }

    }

    /**
     * 判断表格数据类型
     *
     * @param str 原始数据
     * @return true:数字类型，false:字符类型
     * @author: leiming5
     */
    public static boolean isNumeric(String str) {
    
    

        try {
    
    
            Double.valueOf(str);
        } catch (NumberFormatException e) {
    
    
            return false;
        }

        return true;
    }

    /**
     * 设置单元个样式
     *
     * @param workbook 工作簿
     * @param type     自定义单元格类型，head:表头，body:表格主体
     * @return 单元格样式
     * @author: leiming5
     */
    private CellStyle getCellStyle(Workbook workbook, String type) {
    
    

        // Sheet样式
        CellStyle columnHeadStyle = workbook.createCellStyle();
        // 背景色的设定 自动换行
        columnHeadStyle.setWrapText(true);

        //设置字体颜色
        Font font = workbook.createFont();
        short colorIndex;
        switch (type) {
    
    
            case "head":
                colorIndex = HSSFColor.HSSFColorPredefined.RED.getIndex();
                break;
            case "body":
                colorIndex = HSSFColor.HSSFColorPredefined.BLACK.getIndex();
                break;
            default:
                colorIndex = HSSFColor.HSSFColorPredefined.BLACK.getIndex();
        }
        font.setColor(colorIndex);

        //将字体设置应用到当前样式
        columnHeadStyle.setFont(font);

        //水平居中,垂直居中
        columnHeadStyle.setAlignment(HorizontalAlignment.CENTER);
        columnHeadStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        return columnHeadStyle;
    }

    /**
     * 模拟表格数据
     *
     * @return 表格数据
     * @author: leiming5
     */
    private List<List<Object>> generateData() {
    
    

        List<Object> rowOne = Arrays.asList(1, "张三", "男", 18);
        List<Object> rowTwo = Arrays.asList(2, "李四", "女", 19);
        List<Object> rowTree = Arrays.asList(3, "李mao", "女", 21);
        return Arrays.asList(rowOne, rowTwo, rowTree);

    }

    /**
     * 模拟表头字段
     *
     * @return 表头字段
     * @author: leiming5
     */
    private List<List<String>> generateHead() {
    
    

        List<String> headerOne = Arrays.asList("这是标题", "", "", "");
        List<String> headerTwo = Arrays.asList("序号", "姓名", "性别", "年龄");
        return Arrays.asList(headerOne, headerTwo);
    }
}