excel导出

1.工具类

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.util.CellRangeAddress;
import org.apache.poi.xssf.usermodel.*;

import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

public class ExcelUtil {
    private final static String excel2003L =".xls";    //2003- 版本的excel
    private final static String excel2007U =".xlsx";   //2007+ 版本的excel
    /**
     * Excel导入
     */
    public static  List<List<Object>> getBankListByExcel(InputStream in, String fileName) throws Exception{
        List<List<Object>> list = null;
        //创建Excel工作薄
        Workbook work = getWorkbook(in,fileName);
        if(null == work){
            throw new Exception("创建Excel工作薄为空！");
        }
        Sheet sheet = null;
        Row row = null;
        Cell cell = null;
        list = new ArrayList<List<Object>>();
        //遍历Excel中所有的sheet
        for (int i = 0; i < work.getNumberOfSheets(); i++) {
            sheet = work.getSheetAt(i);
            if(sheet==null){continue;}
            //遍历当前sheet中的所有行
            //包涵头部，所以要小于等于最后一列数,这里也可以在初始值加上头部行数，以便跳过头部
            for (int j = sheet.getFirstRowNum(); j <= sheet.getLastRowNum(); j++) {
                //读取一行
                row = sheet.getRow(j);
                //去掉空行和表头
                if(row==null||row.getFirstCellNum()==j){continue;}
                //遍历所有的列
                List<Object> li = new ArrayList<Object>();
                for (int y = row.getFirstCellNum(); y < row.getLastCellNum(); y++) {
                    cell = row.getCell(y);
                    li.add(getCellValue(cell));
                }
                list.add(li);
            }
        }
        return list;
    }
    /**
     * 描述：根据文件后缀，自适应上传文件的版本
     */
    public static  Workbook getWorkbook(InputStream inStr,String fileName) throws Exception{
        Workbook wb = null;
        String fileType = fileName.substring(fileName.lastIndexOf("."));
        if(excel2003L.equals(fileType)){
            wb = new HSSFWorkbook(inStr);  //2003-
        }else if(excel2007U.equals(fileType)){
            wb = new XSSFWorkbook(inStr);  //2007+
        }else{
            throw new Exception("解析的文件格式有误！");
        }
        return wb;
    }
    /**
     * 描述：对表格中数值进行格式化
     */
    public static  Object getCellValue(Cell cell){
        Object value = null;
        DecimalFormat df = new DecimalFormat("0");  //格式化字符类型的数字
        SimpleDateFormat sdf = new SimpleDateFormat("yyy-MM-dd");  //日期格式化
        DecimalFormat df2 = new DecimalFormat("0.00");  //格式化数字
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_STRING:
                value = cell.getRichStringCellValue().getString();
                break;
            case Cell.CELL_TYPE_NUMERIC:
                if("General".equals(cell.getCellStyle().getDataFormatString())){
                    value = df.format(cell.getNumericCellValue());
                }else if("m/d/yy".equals(cell.getCellStyle().getDataFormatString())){
                    value = sdf.format(cell.getDateCellValue());
                }else{
                    value = df2.format(cell.getNumericCellValue());
                }
                break;
            case Cell.CELL_TYPE_BOOLEAN:
                value = cell.getBooleanCellValue();
                break;
            case Cell.CELL_TYPE_BLANK:
                value = "";
                break;
            default:
                break;
        }
        return value;
    }
    /**
     * 导入Excel表结束
     * 导出Excel表开始
     * @param sheetName 工作簿名称
     * @param clazz  数据源model类型
     * @param objs   excel标题列以及对应model字段名
     * @param map  标题列行数以及cell字体样式
     */
    public static XSSFWorkbook createExcelFile(Class clazz, List objs, Map<Integer, List<ExcelBean>> map, String sheetName) throws 
IllegalArgumentException,IllegalAccessException,InvocationTargetException,
ClassNotFoundException, IntrospectionException, ParseException {
        // 创建新的Excel工作簿
        XSSFWorkbook workbook = new XSSFWorkbook();
        // 在Excel工作簿中建一工作表，其名为缺省值, 也可以指定Sheet名称
        XSSFSheet sheet = workbook.createSheet(sheetName);
        // 以下为excel的字体样式以及excel的标题与内容的创建，下面会具体分析;
        createFont(workbook); //字体样式
        createTableHeader(sheet, map); //创建标题（头）
        createTableRows(sheet, map, objs, clazz); //创建内容
        return workbook;
    }
    private static XSSFCellStyle fontStyle;
    private static XSSFCellStyle fontStyle2;
    public static void createFont(XSSFWorkbook workbook) {
        // 表头
        fontStyle = workbook.createCellStyle();
        XSSFFont font1 = workbook.createFont();
        font1.setBoldweight(XSSFFont.BOLDWEIGHT_BOLD);
        font1.setFontName("黑体");
        font1.setFontHeightInPoints((short) 12);// 设置字体大小
        fontStyle.setFont(font1);
        fontStyle.setBorderBottom(XSSFCellStyle.BORDER_THIN); // 下边框
        fontStyle.setBorderLeft(XSSFCellStyle.BORDER_THIN);// 左边框
        fontStyle.setBorderTop(XSSFCellStyle.BORDER_THIN);// 上边框
        fontStyle.setBorderRight(XSSFCellStyle.BORDER_THIN);// 右边框
        fontStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER); // 居中
        // 内容
        fontStyle2=workbook.createCellStyle();
        XSSFFont font2 = workbook.createFont();
        font2.setFontName("宋体");
        font2.setFontHeightInPoints((short) 10);// 设置字体大小
        fontStyle2.setFont(font2);
        fontStyle2.setBorderBottom(XSSFCellStyle.BORDER_THIN); // 下边框
        fontStyle2.setBorderLeft(XSSFCellStyle.BORDER_THIN);// 左边框
        fontStyle2.setBorderTop(XSSFCellStyle.BORDER_THIN);// 上边框
        fontStyle2.setBorderRight(XSSFCellStyle.BORDER_THIN);// 右边框
        fontStyle2.setAlignment(XSSFCellStyle.ALIGN_CENTER); // 居中
    }
    /**
     * 根据ExcelMapping 生成列头（多行列头）
     *
     * @param sheet 工作簿
     * @param map 每行每个单元格对应的列头信息
     */
    public static final void createTableHeader(XSSFSheet sheet, Map<Integer, List<ExcelBean>> map) {
        int startIndex=0;//cell起始位置
        int endIndex=0;//cell终止位置
        for (Map.Entry<Integer, List<ExcelBean>> entry : map.entrySet()) {
            XSSFRow row = sheet.createRow(entry.getKey());
            List<ExcelBean> excels = entry.getValue();
            for (int x = 0; x < excels.size(); x++) {
                //合并单元格
                if(excels.get(x).getCols()>1){
                    if(x==0){
                        endIndex+=excels.get(x).getCols()-1;
                        CellRangeAddress range=new CellRangeAddress(0,0,startIndex,endIndex);
                        sheet.addMergedRegion(range);
                        startIndex+=excels.get(x).getCols();
                    }else{
                        endIndex+=excels.get(x).getCols();
                        CellRangeAddress range=new CellRangeAddress(0,0,startIndex,endIndex);
                        sheet.addMergedRegion(range);
                        startIndex+=excels.get(x).getCols();
                    }
                    XSSFCell cell = row.createCell(startIndex-excels.get(x).getCols());
                    cell.setCellValue(excels.get(x).getHeadTextName());// 设置内容
                    if (excels.get(x).getCellStyle() != null) {
                        cell.setCellStyle(excels.get(x).getCellStyle());// 设置格式
                    }
                    cell.setCellStyle(fontStyle);
                }else{
                    XSSFCell cell = row.createCell(x);
                    cell.setCellValue(excels.get(x).getHeadTextName());// 设置内容
                    if (excels.get(x).getCellStyle() != null) {
                        cell.setCellStyle(excels.get(x).getCellStyle());// 设置格式
                    }
                    cell.setCellStyle(fontStyle);
                }
            }
        }
    }
    public static void createTableRows(XSSFSheet sheet, Map<Integer, List<ExcelBean>> map, List objs, Class clazz)
            throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, IntrospectionException,
            ClassNotFoundException, ParseException {
        int rowindex = map.size();
        int maxKey = 0;
        List<ExcelBean> ems = new ArrayList<ExcelBean>();
        for (Map.Entry<Integer, List<ExcelBean>> entry : map.entrySet()) {
            if (entry.getKey() > maxKey) {
                maxKey = entry.getKey();
            }
        }
        ems = map.get(maxKey);
        List<Integer> widths = new ArrayList<Integer>(ems.size());
        for (Object obj : objs) {
            XSSFRow row = sheet.createRow(rowindex);
            for (int i = 0; i < ems.size(); i++) {
                ExcelBean em = (ExcelBean) ems.get(i);
                // 获得get方法
                PropertyDescriptor pd = new PropertyDescriptor(em.getPropertyName(), clazz);
                Method getMethod = pd.getReadMethod();
                Object rtn = getMethod.invoke(obj);
                String value = "";
                // 如果是日期类型进行转换
                if (rtn != null) {
                    if (rtn instanceof Date) {
                        value = DateUtils.getDate("yyyy-MM-dd",(Date)rtn);
                    } else if(rtn instanceof BigDecimal){
                        NumberFormat nf = new DecimalFormat("#,##0.00");
                        value=nf.format((BigDecimal)rtn).toString();
                    } else if((rtn instanceof Integer) && (Integer.valueOf(rtn.toString())<0 )){
                        value="--";
                    }else {
                        value = rtn.toString();
                    }
                }
                XSSFCell cell = row.createCell(i);
                cell.setCellValue(value);
                cell.setCellType(XSSFCell.CELL_TYPE_STRING);
                cell.setCellStyle(fontStyle2);
                // 获得最大列宽
                int width = value.getBytes().length * 300;
                // 还未设置，设置当前
                if (widths.size() <= i) {
                    widths.add(width);
                    continue;
                }
                // 比原来大，更新数据
                if (width > widths.get(i)) {
                    widths.set(i, width);
                }
            }
            rowindex++;
        }
        // 设置列宽
        for (int index = 0; index < widths.size(); index++) {
            Integer width = widths.get(index);
            width = width < 2500 ? 2500 : width + 300;
            width = width > 10000 ? 10000 + 300 : width + 300;
            sheet.setColumnWidth(index, width);
        }
    }
}

2.controller调用

import SSM.model.Card;
import SSM.utils.ExcelBean;
import SSM.utils.ExcelUtil;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.*;

/**
 * @author zhouhe
 * @date 2020/7/14 17:06
 */
@Controller
@RequestMapping("/test")
public class Test {

    /**
     * 导出
     * @param request
     * @param response
     */
    @RequestMapping("/list/export")
    public @ResponseBody
    void listexport(HttpServletRequest request, HttpServletResponse response) {
        XSSFWorkbook wb = exportExcelList();
        response.setContentType("application/vnd.ms-excel");
        String filename="流量统计.xlsx";
        try {
            response.setHeader("content-disposition", "attachment;filename="+ URLEncoder.encode(filename, "UTF-8") );
        } catch (UnsupportedEncodingException e1) {
            e1.printStackTrace();
        }
        OutputStream ouputStream = null;
        try {
            ouputStream = response.getOutputStream();
            wb.write(ouputStream);
        } catch (Exception e) {
            throw new RuntimeException("系统异常");
        } finally {
            try {
                ouputStream.flush();
                ouputStream.close();
            } catch (Exception e) {
                throw new RuntimeException("系统异常");
            }
        }
    }
    
    /**
     * 导出excel
     * @return
     */
    public static XSSFWorkbook exportExcelList() {
        try {
            //这个数据可以从数据库中读取
            List<Card> list = new ArrayList<Card>();

            List<ExcelBean> excel = new ArrayList<ExcelBean>();
            Map<Integer, List<ExcelBean>> map = new LinkedHashMap<Integer, List<ExcelBean>>();
            XSSFWorkbook xssfWorkbook = null;
            //设置标题栏
            excel.add(new ExcelBean("卡号", "iccid", 0));
            excel.add(new ExcelBean("当月已用(MB)", "flow", 0));
            excel.add(new ExcelBean("昨日用量(MB)", "yesterdayflow", 0));
            map.put(0, excel);
            String sheetName = "流量统计";
            //调用ExcelUtil的方法

            xssfWorkbook = ExcelUtil.createExcelFile(Card.class, list, map, sheetName);

            return xssfWorkbook;
        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }
}