easyexcel基于模板生成报表

对比了一下 easyexcel ，jxls , poi-tl 等工具，感觉各有千秋。

做个笔记，有需要的同学可以进行参考

github地址：https://github.com/alibaba/easyexcel

1、先定义模板

2、上代码

package com.luo.easyexcel.demos;

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.Head;
import com.alibaba.excel.metadata.data.WriteCellData;
import com.alibaba.excel.write.handler.CellWriteHandler;

import com.alibaba.excel.write.metadata.WriteSheet;
import com.alibaba.excel.write.metadata.fill.FillConfig;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
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.util.CellRangeAddress;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.*;

public class BasicTest {

    public static void main(String[] args) {
        ExcelWriter excelWriter = EasyExcel.write("D:\\result.xlsx", User.class)
                .withTemplate("D:\\template.xlsx")
                .registerWriteHandler(new FillRowMergeStrategy())
                .autoCloseStream(false)
                .build();
        WriteSheet writeSheet = EasyExcel.writerSheet().build();
        FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();
        Map<String, Object> params = new HashMap<>(8);
        params.put("spr", "张三");
        params.put("spsj", LocalDateTime.now());
        params.put("cjr", "李四");
        params.put("cjsj", LocalDateTime.now());
        excelWriter.fill(params, writeSheet);
        excelWriter.fill(getData(), fillConfig, writeSheet);
        // 完成写入
        excelWriter.finish();
    }


    private static class FillRowMergeStrategy implements CellWriteHandler {
        /** 需要进行单元格合并的列数组 **/
        private int mergeColumnIndex = 0;

        private int mergeRowIndex = 4;

        /**
         * 在每个单元格写入完成后执行，适合做样式、合并、校验等操作
         * @param writeSheetHolder 当前 sheet 的上下文信息（如当前行、sheet 对象等）
         * @param writeTableHolder 表格相关上下文（通常不常用）
         * @param cellDataList 当前单元格的数据集合（包含样式、值等）
         * @param cell
         * @param head 表头信息
         * @param relativeRowIndex 当前行在数据中的索引（从 0 开始）
         * @param isHead 是否是表头
         */
        @Override
        public void afterCellDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<WriteCellData<?>> cellDataList, Cell cell, Head head, Integer relativeRowIndex, Boolean isHead) {
            int curRowIndex = cell.getRowIndex();
            int curColIndex = cell.getColumnIndex();
            if (curRowIndex > mergeRowIndex) {
                if (curColIndex == mergeColumnIndex) {
                    mergeWithPrevRow(writeSheetHolder, cell, curRowIndex, curColIndex);
                }
            }
        }

        /**
         * 当前单元格向上合并
         *
         * @param writeSheetHolder
         * @param cell
         *            当前单元格
         * @param curRowIndex
         *            当前行
         * @param curColIndex
         *            当前列
         */
        private void mergeWithPrevRow(WriteSheetHolder writeSheetHolder, Cell cell, int curRowIndex, int curColIndex) {
            Object curData = getCellValue(cell);
            Row preRow = cell.getSheet().getRow(curRowIndex - 1);
            if (preRow == null) {
                // 当获取不到上一行数据时，使用缓存sheet中数据
                preRow = writeSheetHolder.getCachedSheet().getRow(curRowIndex - 1);
            }
            Cell preCell = preRow.getCell(curColIndex);
            Object preData =  getCellValue(preCell);
            // 将当前单元格数据与上一个单元格数据比较
            boolean same = preData.equals(curData);
            if (same) {
                Sheet sheet = writeSheetHolder.getSheet();
                List<CellRangeAddress> mergeRegions = sheet.getMergedRegions();
                boolean isMerged = false;
                for (int i = 0; i < mergeRegions.size() && !isMerged; i++) {
                    CellRangeAddress cellRangeAddr = mergeRegions.get(i);
                    // 若上一个单元格已经被合并，则先移出原有的合并单元，再重新添加合并单元
                    if (cellRangeAddr.isInRange(curRowIndex - 1, curColIndex)) {
                        sheet.removeMergedRegion(i);
                        cellRangeAddr.setLastRow(curRowIndex);
                        sheet.addMergedRegion(cellRangeAddr);
                        isMerged = true;
                    }
                }
                // 若上一个单元格未被合并，则新增合并单元
                if (!isMerged) {
                    CellRangeAddress cellRangeAddress = new CellRangeAddress(curRowIndex - 1, curRowIndex, curColIndex, curColIndex);
                    sheet.addMergedRegion(cellRangeAddress);
                }
            }
        }

        // 获取单元格值
        private Object getCellValue(Cell cell) {
            switch (cell.getCellType()) {
                case STRING:
                    return cell.getStringCellValue();
                case NUMERIC:
                    return cell.getNumericCellValue();
                case BOOLEAN:
                    return cell.getBooleanCellValue();
                default:
                    return null;
            }
        }
    }


    /**
     * 测试数据
     */
    private static List<User> getData() {
        List<User> userList = new ArrayList<>();
        for (int i = 1; i <= 10; i++) {
            if (i > 5) {
                userList.add(new User("张三" + i,"男", "北京"+i, LocalDate.now(), "17745528756", "xxxxxxx", 18));
            }else if (i > 3){
                userList.add(new User("张三" + i,"男", "北京"+i, LocalDate.now(), "17745528756", "xxxxxxx", 19));
            }else {
                userList.add(new User("张三" + i,"男", "北京"+i, LocalDate.now(), "17745528756", "xxxxxxx", 20));
            }
        }
        return userList;
    }
}

效果如下