POI導出excle(項目)

首先引入依賴(低版本和高版本設置樣式的時候會有區別)

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>4.1.0</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.0</version>
</dependency>

創建ExcelUtils工具類

import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * @author wyc
 * @date 2019/8/2 14:20
 */
public class ExcelUtils {

    private static final Logger logger = LoggerFactory.getLogger(ExcelUtils.class);
    private static final int PAGE_NUM = 50;


    //導出excle
    public void exportExcle(HttpServletResponse response, String fileName, List<Map<String, Object>> list) {
        //標題名字
        String[] title = {"主鍵", "權限", "描述", "插入時間", "是否可用", "父節點", "權限類型", "是否顯示"};
        OutputStream os = null;
        HSSFWorkbook workBook = null;
        try {
            StringBuffer sbBuffer = new StringBuffer();
            sbBuffer.append(fileName + "__");
            sbBuffer.append(doDate2String(new Date()));
            sbBuffer.append(".xls");
            String finallyFileName = sbBuffer.toString();
            os = response.getOutputStream();
            //設置響應頭
            setResponseHeader(response, finallyFileName);
            //生成workBook
            workBook = getHSSFWorkbook(list, title);
            workBook.write(os);
        } catch (IOException e) {
            logger.error("", e);
        } finally {
            try {
                if (workBook != null) {
                    workBook.close();
                }
            } catch (IOException e) {
                logger.error("", e);
            }
            try {
                if (os != null) {
                    os.close();
                }
            } catch (IOException e) {
                logger.error("", e);
            }
        }
    }

    /**
     * 獲取工作簿
     *
     * @param list
     * @param columnMap
     * @return
     * @throws Exception
     */
    public HSSFWorkbook getHSSFWorkbook(List<Map<String, Object>> list, String[] excelHeader) {

        HSSFWorkbook wb = new HSSFWorkbook();
        //對集合進行非空判斷
        if (isEmptyOrNull(list) || isEmptyOrNull(excelHeader)) {
            wb.createSheet();
            return wb;
        }

        int pageNum = PAGE_NUM;//每頁數量
        int size = list.size();//數據數量
        int pages = (size % pageNum > 0) ? (size / pageNum + 1) : (size / pageNum);//導出頁數

//        HSSFCellStyle cellStyle = null;//單元格樣式
        HSSFSheet sheet = null;//頁面

/*        HSSFFont font = wb.createFont();//字體
        font.setFontHeightInPoints((short) 11);//設置字號
        cellStyle = wb.createCellStyle();
        cellStyle.setFont(font);
//        cellStyle.setFillPattern(HSSFCellStyle.FINE_DOTS);
        cellStyle.setFillPattern(FillPatternType.FINE_DOTS);*/

        HSSFRow row = null;//單元格行
        Map<String, Object> dataMap = null;
        for (int j = 0; j < pages; j++) {
            sheet = wb.createSheet();
            //設置sheet的名字
            wb.setSheetName(j, (String.valueOf((j + 1))));

            //設置列寬
            columnWidthSet(sheet, size);
            //創建行
            row = sheet.createRow(0);

            //設置行高
//            row.setHeight((short) 500);

            //設置表頭
            for (int i = 0; i < excelHeader.length; i++) {
                HSSFCell cell = row.createCell(i);
                cell.setCellValue(excelHeader[i]);
                cell.setCellStyle(getTopStyle(wb));
            }
            //填充數據
            for (int i = pageNum * j; i < pageNum * j + pageNum && i < size; i++) {
                //表頭佔幾行,填充數據時就從後面開始填充,後面加的1就是代表表頭佔幾行,佔幾行就加幾
                row = sheet.createRow(i - pageNum * j + 1);

                //設置行高
//                row.setHeight((short) 500);

                //獲取單元格樣式
                HSSFCellStyle cellStyle = getStyle(wb);

                Map<String, Object> map = list.get(i);

                createCell(row, 0, map.get("id") == null ? "/" : map.get("id").toString(), cellStyle);
                createCell(row, 1, map.get("permission") == null ? "/" : map.get("permission").toString(), cellStyle);
                createCell(row, 2, map.get("description") == null ? "/" : map.get("description").toString(), cellStyle);
                createCell(row, 3, map.get("insertDt") == null ? "/" : map.get("insertDt").toString(), cellStyle);
                createCell(row, 4, map.get("available") == null ? "/" : map.get("available").toString(), cellStyle);
                createCell(row, 5, map.get("pid") == null ? "/" : map.get("pid").toString(), cellStyle);
                createCell(row, 6, map.get("type") == null ? "/" : map.get("type").toString(), cellStyle);
                createCell(row, 7, map.get("showStatus") == null ? "/" : map.get("showStatus").toString(), cellStyle);
            }

        }
        return wb;
    }
    /**
     * 創建單元格
     *
     * @param row
     * @param column
     * @param value
     * @param cellStyle
     */
    private void createCell(HSSFRow row, int column, String value, CellStyle cellStyle) {
        HSSFCell cell = row.createCell(column);
        //設置單元格的值
        cell.setCellValue(value);
        if (cellStyle != null) {
            //設置單元格的樣式
            cell.setCellStyle(cellStyle);
        }
    }


    //發送響應流方法
    private void setResponseHeader(HttpServletResponse response, String fileName) {
        try {
            try {
                fileName = new String(fileName.getBytes(), "ISO8859-1");
            } catch (UnsupportedEncodingException e) {
                //TODO 處理異常
                logger.error("", e);
            }
            response.setContentType("application/octet-stream;charset=ISO8859-1");
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
        } catch (Exception ex) {
            //TODO 處理異常
            logger.error("", ex);
        }
    }

    /**
     * 列寬設置
     */
    private void columnWidthSet(HSSFSheet sheet, int size) {
        for (int i = 0; i < size; i++) {
            sheet.setColumnWidth(i, 5000);
        }
    }


    /**
     * 寬度設置,讓列寬隨着導出的列長自動適應(可能不能用)
     */
/*
    private void columnWidthSet(HSSFSheet sheet, int size) {

        // 讓列寬隨着導出的列長自動適應
        for (int colNum = 0; colNum < size; colNum++) {
            int columnWidth = sheet.getColumnWidth(colNum) / 256;
            for (int rowNum = 0; rowNum < sheet.getLastRowNum(); rowNum++) {
                HSSFRow currentRow;
                // 當前行未被使用過
                if (sheet.getRow(rowNum) == null) {
                    currentRow = sheet.createRow(rowNum);
                } else {
                    currentRow = sheet.getRow(rowNum);
                }
                if (currentRow.getCell(colNum) != null) {
                    HSSFCell currentCell = currentRow.getCell(colNum);
                    if (currentCell.getCellType() == CellType.STRING) {
                        int length = currentCell.getStringCellValue()
                                .getBytes().length;
                        if (columnWidth < length) {
                            columnWidth = length;
                        }
                    }
                }
            }
            if (colNum == 0) {
                sheet.setColumnWidth(colNum, (columnWidth - 2) * 256);
            } else {
                sheet.setColumnWidth(colNum, (columnWidth + 4) * 256);
            }
        }
    }
*/


    /**
     * 列頭單元格樣式
     */
    private HSSFCellStyle getTopStyle(HSSFWorkbook workbook) {

        // 設置字體
        HSSFFont font = workbook.createFont();
        // 設置字體大小
        font.setFontHeightInPoints((short) 11);
        // 字體加粗
        font.setBold(true);
        // 設置字體名字
        font.setFontName("Courier New");
        // 設置樣式;
        HSSFCellStyle style = workbook.createCellStyle();
        // 設置底邊框;
        style.setBorderBottom(BorderStyle.THIN);
        // 設置底邊框顏色;
        style.setBottomBorderColor(IndexedColors.BLACK.index);
        // 設置左邊框;
        style.setBorderLeft(BorderStyle.THIN);
        // 設置左邊框顏色;
        style.setLeftBorderColor(IndexedColors.BLACK.index);
        // 設置右邊框;
        style.setBorderRight(BorderStyle.THIN);
        // 設置右邊框顏色;
        style.setRightBorderColor(IndexedColors.BLACK.index);
        // 設置頂邊框;
        style.setBorderTop(BorderStyle.THIN);
        // 設置頂邊框顏色;
        style.setTopBorderColor(IndexedColors.BLACK.index);
        // 在樣式用應用設置的字體;
        style.setFont(font);
        // 設置自動換行;
        style.setWrapText(false);
        // 設置水平對齊的樣式爲居中對齊;
        style.setAlignment(HorizontalAlignment.CENTER);
        // 設置垂直對齊的樣式爲居中對齊;
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        return style;
    }

    /**
     * 列數據信息單元格樣式
     */
    private HSSFCellStyle getStyle(HSSFWorkbook workbook) {
        // 設置字體
        HSSFFont font = workbook.createFont();
        // 設置字體大小
        // font.setFontHeightInPoints((short)10);
        // 字體加粗
        // font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
        // 設置字體名字
        font.setFontName("Courier New");
        // 設置樣式;
        HSSFCellStyle style = workbook.createCellStyle();
        // 設置底邊框;
        style.setBorderBottom(BorderStyle.THIN);
        // 設置底邊框顏色;
        style.setBottomBorderColor(IndexedColors.BLACK.index);
        // 設置左邊框;
        style.setBorderLeft(BorderStyle.THIN);
        // 設置左邊框顏色;
        style.setLeftBorderColor(IndexedColors.BLACK.index);
        // 設置右邊框;
        style.setBorderRight(BorderStyle.THIN);
        // 設置右邊框顏色;
        style.setRightBorderColor(IndexedColors.BLACK.index);
        // 設置頂邊框;
        style.setBorderTop(BorderStyle.THIN);
        // 設置頂邊框顏色;
        style.setTopBorderColor(IndexedColors.BLACK.index);
        // 在樣式用應用設置的字體;
        style.setFont(font);
        // 設置自動換行;
        style.setWrapText(false);
        // 設置水平對齊的樣式爲居中對齊;
        style.setAlignment(HorizontalAlignment.CENTER);
        // 設置垂直對齊的樣式爲居中對齊;
        style.setVerticalAlignment(VerticalAlignment.CENTER);
        return style;
    }


    /**
     * 將日期轉化爲String
     *
     * @param confirmDate
     * @param patten
     * @return
     */
    public static String doDate2String(Date confirmDate, String... patten) {
        if (confirmDate == null) {
            return "";
        }
        SimpleDateFormat sdf = null;
        if (patten == null || patten.length == 0) {
            sdf = new SimpleDateFormat("yyyy-MM-dd");
        } else {
            sdf = new SimpleDateFormat(patten[0]);
        }
        return sdf.format(new Date(confirmDate.getTime()));
    }


    /**
     * 非空判斷
     *
     * @param obj
     * @return
     */
    public boolean isEmptyOrNull(Object obj) {
        if (obj == null) {
            return true;
        }
        if (obj instanceof Map) {
            return ((Map) obj).isEmpty();
        } else if (obj instanceof List) {
            return ((List) obj).isEmpty();
        }
        return obj.toString().isEmpty();
    }


}

controller層

import com.comvee.intelligentp.authority.model.po.AuthorityPO;
import com.comvee.intelligentp.authority.service.AuthorityService;
import com.comvee.intelligentp.common.wrapper.Result;
import com.comvee.intelligentp.export.util.ExcelUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author wyc
 * @date 2019/8/2 15:15
 */
@RestController
@RequestMapping("/web/testExport")
public class TestExportController {
    @Autowired
    private AuthorityService authorityService;
    @RequestMapping("export")
    public Result testExport(HttpServletResponse response){
        //excle文檔的名字
        String fileName = "數據導出";
        //自己實現數據查詢
        List<AuthorityPO> pos = this.authorityService.listAuthority(null, null, null);
        //可以將數據封裝到map集合,也可以封裝到對象裏面(比如封裝到對象裏面就可以直接使用上面的集合pos傳參,工具類裏面要做相應的修改)
        List<Map<String, Object>> list = new ArrayList<>();
        if ( null != pos && pos.size() >0){
            for (AuthorityPO po : pos) {
                Map<String, Object> map = new HashMap<>();
                map.put("id",po.getSid());
                map.put("permission",po.getPermission());
                map.put("description",po.getDescription());
                map.put("insertDt",po.getInsertDt());
                map.put("available",po.getAvailable());
                map.put("pid",po.getPid());
                map.put("type",po.getaType());
                map.put("status",po.getShowStatus());
                list.add(map);
            }
        }
        ExcelUtils excelUtils = new ExcelUtils();
        excelUtils.exportExcle(response,fileName,list);
        return new Result("導出成功");
    }
}