EasyExcel 批量导出

---

前言

上篇写了数据导入，本文补充一下EasyExcel 批量导出
包括常规excel和复杂excel

一、EasyExcel 导出封装

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.builder.ExcelWriterSheetBuilder;
import com.alibaba.excel.write.handler.WriteHandler;
import com.alibaba.excel.write.metadata.WriteSheet;
import com.google.common.base.Charsets;
import com.gsafety.bg.gsdss.common.contants.CommonConstants;
import com.gsafety.bg.gsdss.common.exception.BusinessException;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.AtomicReference;

/**
 * AbstractExcelView
 */
@Slf4j
public abstract class AbstractExcelView {

    private String excelName;

    private ExcelTypeEnum excelType;

    private HttpServletResponse response;

    public AbstractExcelView(HttpServletResponse response, String excelName, ExcelTypeEnum excelType) {
        this.excelName = excelName;
        this.excelType = excelType;
        this.response = response;
    }

    protected OutputStream prepareResponse(HttpServletResponse response) throws Exception {
        response.setContentType(CommonConstants.CONTENT_TYPE_EXCEL);
        response.setCharacterEncoding(Charsets.UTF_8.name());
        response.setHeader("content-disposition", "attachment;filename=" + URLEncoder.encode(excelName, Charsets.UTF_8.name()) + excelType.getValue());
        return response.getOutputStream();
    }

    public void exportExcel() {
        ExcelWriter excelWriter = null;
        try {
            List> sheets = this.sheets();
            if (CollectionUtils.isEmpty(sheets)) {
                return;
            }
            excelWriter = EasyExcel.write(this.prepareResponse(response)).excelType(excelType).build();
            for (Sheet s : sheets) {
                ExcelWriterSheetBuilder sb = EasyExcel.writerSheet(s.getIndex(), s.getName()).head(s.getClz());
                if (CollectionUtils.isNotEmpty(s.getHandlers())) {
                    List l = s.getHandlers();
                    l.forEach(h -> sb.registerWriteHandler(h));
                }
                if (CollectionUtils.isNotEmpty(this.sheetDynamicHead(s.getIndex()))){
                    sb.head(this.sheetDynamicHead(s.getIndex()));
                }
                excelWriter.write(this.sheetData(s.getIndex()), sb.build());
            }
        } catch (Exception e) {
            log.error(" 导出失败! ", e);
            throw new BusinessException(" 导出失败! ");
        } finally {
            if (Objects.nonNull(excelWriter)) {
                excelWriter.finish();
            }
        }
    }

    public String asyncExport(ThreadPoolTaskExecutor executor) {
        AtomicReference result = new AtomicReference<>(StringUtils.EMPTY);
        ExcelWriter excelWriter = null;
        try {
            List> sheets = this.sheets();
            if (CollectionUtils.isEmpty(sheets)) {
                return result.get();
            }
            excelWriter = EasyExcel.write(this.prepareResponse(response)).excelType(excelType).build();
            WriteSheet[] writeSheets = sheets.stream().map(sheet -> {
                ExcelWriterSheetBuilder sb = EasyExcel.writerSheet(sheet.getIndex(), sheet.getName())
                        .head(sheet.getClz());
                if (CollectionUtils.isNotEmpty(sheet.getHandlers())) {
                    List l = sheet.getHandlers();
                    l.forEach(h -> sb.registerWriteHandler(h));
                }
                if (CollectionUtils.isNotEmpty(this.sheetDynamicHead(sheet.getIndex()))){
                    sb.head(this.sheetDynamicHead(sheet.getIndex()));
                }
                return sb.build();
            }).toArray(WriteSheet[]::new);
            ExcelWriter finalExcelWriter = excelWriter;
            CompletableFuture[] cfs = sheets.stream()
                    .map(sheet -> CompletableFuture.runAsync(
                            () -> {
                                log.info(" 当前sheet {} {} ", sheet.getIndex(), sheet.getName());

                                log.info(" 当前sheet {} ", writeSheets[sheet.getIndex()]);
                                finalExcelWriter.write(this.sheetData(sheet.getIndex()), writeSheets[sheet.getIndex()]);
                            }, executor)
                                    .exceptionally((e) -> {
                                                result.set(sheet.getName() + " 导出失败 ");
                                                log.error(sheet.getName() + " 导出失败 ", e);
                                                return null;
                                            }
                                    )
                    ).toArray(CompletableFuture[]::new);

            CompletableFuture.allOf(cfs).join();
        } catch (Exception e) {
            log.error(" 导出失败! ", e);
            throw new BusinessException(" 导出失败! ");
        } finally {
            if (Objects.nonNull(excelWriter)) {
                excelWriter.finish();
            }
        }
        return result.get();
    }

    protected abstract List> sheets();

    protected abstract List sheetData(int sheetIndex);

    protected List> sheetDynamicHead(int sheetIndex){
        return null;
    }

}

二、食用步骤

1.自定义excel样式

import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.metadata.style.WriteFont;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import org.apache.poi.ss.usermodel.*;

/**
 * @description excel样式策略类
 */

public class ExcelCustomStyleStrategy {

    public static HorizontalCellStyleStrategy getSimpleStyle(){
        // 头的策略
        WriteCellStyle headWriteCellStyle = new WriteCellStyle();
        // 设置对齐
        headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        // 背景色
        headWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE1.getIndex());
        // 字体策略
        WriteFont headWriteFont = new WriteFont();
        headWriteFont.setBold(false);
        headWriteFont.setFontName("微软雅黑");
        headWriteFont.setFontHeightInPoints((short) 12);
        headWriteCellStyle.setWriteFont(headWriteFont);

        // 内容的策略
        WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
        contentWriteCellStyle.setFillPatternType(FillPatternType.SOLID_FOREGROUND);
        // 背景色
        // 这里需要指定 FillPatternType 为FillPatternType.SOLID_FOREGROUND 不然无法显示背景颜色。头默认了 FillPatternType所以可以不指定。
        contentWriteCellStyle.setFillPatternType(FillPatternType.SOLID_FOREGROUND);
        //背景设置白色
        contentWriteCellStyle.setFillForegroundColor(IndexedColors.WHITE1.getIndex());
        // 字体策略
        WriteFont contentWriteFont = new WriteFont();
        //contentWriteFont.setFontHeightInPoints((short) 12);
        contentWriteCellStyle.setWriteFont(contentWriteFont);
        //设置 自动换行
        contentWriteCellStyle.setWrapped(false);
        //设置 垂直居中
        contentWriteCellStyle.setVerticalAlignment(VerticalAlignment.CENTER);
        //设置 水平居中
        contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
        //设置边框样式
        contentWriteCellStyle.setBorderLeft(BorderStyle.THIN);
        contentWriteCellStyle.setBorderTop(BorderStyle.THIN);
        contentWriteCellStyle.setBorderRight(BorderStyle.THIN);
        contentWriteCellStyle.setBorderBottom(BorderStyle.THIN);
        HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
        return horizontalCellStyleStrategy;
    }

}

2.导出数据

import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.style.column.SimpleColumnWidthStyleStrategy;
import com.google.common.collect.Lists;
import com.gsafety.bg.gsdss.common.excel.out.AbstractExcelView;
import com.gsafety.bg.gsdss.common.excel.out.Sheet;
import com.gsafety.bg.sv.controller.excel.strategy.ExcelCustomStyleStrategy;
import com.gsafety.bg.sv.model.dto.resp.AccidentEduExcelResp;

import javax.servlet.http.HttpServletResponse;
import java.util.List;

public class AccidentEduExcelView extends AbstractExcelView<AccidentEduExcelResp> {
	//导出数据list对象 对象属性用@ExcelProperty("事故名称")即可生成表头
    private final List<AccidentEduExcelResp> data;

    public AccidentEduExcelView(HttpServletResponse response, List<AccidentEduExcelResp> data, String excelName) {
        super(response, excelName, ExcelTypeEnum.XLSX);
        this.data = data;
    }
	
	//定义excel样式、sheet名称等
    @Override
    protected List<Sheet<AccidentEduExcelResp>> sheets() {
        return Lists.newArrayList(Sheet.<AccidentEduExcelResp>builder().name("事故警示教育")
                .handlers(Lists.newArrayList(ExcelCustomStyleStrategy.getSimpleStyle(), new SimpleColumnWidthStyleStrategy(30))).clz(AccidentEduExcelResp.class).build());
    }
	
	//指定sheet页
    @Override
    protected List<AccidentEduExcelResp> sheetData(int sheetIndex) {
        return data;
    }

}

    @ApiOperation(value = "列表导出")
    @PostMapping("/v1/list/export")
    public void downLoadList(@RequestBody AccidentEduQO req, HttpServletResponse response) {
    	//查询导出数据list 对象
        List<AccidentEduExcelResp> data = service.list(req);
        new AccidentEduExcelView(response,data,"事故警示教育").exportExcel();
    }

三、复杂excel导出

3.1. 自定义复杂表头

通过重写sheetDynamicHead方法自定义复杂表头
@ExcelProperty(order = 0)注解指定excel列即可填充到指定单元格

import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.style.column.SimpleColumnWidthStyleStrategy;
import com.google.common.collect.Lists;
import com.gsafety.bg.gsdss.common.excel.out.AbstractExcelView;
import com.gsafety.bg.gsdss.common.excel.out.Sheet;
import com.gsafety.bg.sv.controller.excel.strategy.ExcelCustomStyleStrategy;
import com.gsafety.bg.sv.model.dto.resp.AccidentEduSLResp;
import com.gsafety.bg.sv.model.dto.resp.AccidentEduStatisticResp;

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

public class AccidentEduSExcelView extends AbstractExcelView<AccidentEduSLResp> {

    private AccidentEduStatisticResp data;

    private Integer total;

    public AccidentEduSExcelView(HttpServletResponse response, AccidentEduStatisticResp data, String excelName) {
        super(response, excelName, ExcelTypeEnum.XLSX);
        this.data = data;
        this.total = data.getTotal();
    }

    @Override
    protected List<Sheet<AccidentEduSLResp>> sheets() {
        return Lists.newArrayList(Sheet.<AccidentEduSLResp>builder().name("警示教育信息")
                .handlers(Lists.newArrayList(ExcelCustomStyleStrategy.getSimpleStyle(),new SimpleColumnWidthStyleStrategy(30))).clz(AccidentEduSLResp.class).build());
    }

    @Override
    protected List<AccidentEduSLResp> sheetData(int sheetIndex) {
        return data.getList();
    }
	
	//这里是动态表头，需要读取数据库计算数据数量做表头，所以中间走了一层，如果不是动态数据可直接返回sheetDynamicHead(Integer total)方法的内容
    @Override
    protected List<List<String>> sheetDynamicHead(int sheetIndex) {
        return sheetDynamicHead(this.total);
    }

    private List<List<String>> sheetDynamicHead(Integer total){
        List<List<String>> head = Lists.newArrayList();
        head.add(new ArrayList() {{
            add(" ");
            add(" ");
            add(" ");
        }});
        head.add(new ArrayList() {{
            add("参与执法持证人员数");
            add("参与执法持证人员数");
            add("参与执法持证人员数");
        }});
        head.add(new ArrayList() {{
            add("执法检查次数(次)");
            add("合计");
            add("合计");
        }});
        head.add(new ArrayList() {{
            add("执法检查次数(次)");
            add("检查");
            add("检查");
        }});
        head.add(new ArrayList() {{
            add("执法检查次数(次)");
            add("复查");
            add("复查");
        }});
        return head;
    }

}

2. 多sheet

protected List sheets() 方法内返回多个sheet
protected List sheetData(int sheetIndex)方法内指定sheet填充的数据

import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.style.column.SimpleColumnWidthStyleStrategy;
import com.google.common.collect.Lists;
import com.gsafety.bg.emis.base.utils.ExcelCustomStyleStrategy;
import com.gsafety.bg.emis.euip.model.resp.EuipExcelListResp;
import com.gsafety.bg.emis.fpln.model.dto.resp.UavInfoResp;
import com.gsafety.bg.gsdss.common.excel.out.AbstractExcelView;
import com.gsafety.bg.gsdss.common.excel.out.Sheet;

import javax.servlet.http.HttpServletResponse;
import java.util.List;

public class EuipExcelView extends AbstractExcelView {
    private final List<EuipExcelListResp> euip;
    private final List<UavInfoResp> uva;
    
    public EuipExcelView(HttpServletResponse response, List<EuipExcelListResp> euip, List<UavInfoResp> uav, String excelName) {
        super(response, excelName, ExcelTypeEnum.XLSX);
        this.euip = euip;
        this.uva = uav;
    }
    
    @Override
    protected List<Sheet> sheets() {
        return Lists.newArrayList(Sheet.<EuipExcelListResp>builder().name("通讯装备信息")
                        .index(0)
                        .handlers(Lists.newArrayList(ExcelCustomStyleStrategy.getSimpleStyle(), new SimpleColumnWidthStyleStrategy(30))).clz(EuipExcelListResp.class).build(),
                Sheet.<UavInfoResp>builder().name("无人机信息").index(1)
                        .handlers(Lists.newArrayList(ExcelCustomStyleStrategy.getSimpleStyle(), new SimpleColumnWidthStyleStrategy(30))).clz(UavInfoResp.class).build());
        
    }
    
    @Override
    protected List sheetData(int sheetIndex) {
        if (0 == sheetIndex) {
            return euip;
        } else {
            return uva;
        }
    }
    
}