在一般不管大的或者小的系统中，各家的产品都一样，闲的无聊的时候都喜欢让我们这些程序员导出一些数据出来供他观赏，非说这是必须需求，非做不可，那么我们就只能苦逼的哼哧哼哧的写bug喽。
之前使用POI导出excel需要自己先去创建excel文件，还要创建sheet，写表头，操作起来确实很麻烦，针对产品这种随心而欲的需求我们能不能快速的做完这样一个产品看起来挺简单的功能。
基于这样一个快速开发的场景，我们来看看easyexcel应该如何使用。
首先我们创建一个springboot（版本是 2.1.4.RELEASE）项目，在此就不过多的啰嗦，创建好之后，首先需要引入easyexcel的maven坐标。
<dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>1.1.2-beta5</version></dependency>复制代码
导入好了之后，我们接下来需要创建一个导出的模板类，首先要集成BaseRowModel，set、get省略，@ExcelProperty注解中的value就是表头的信息，index是在第几列，没有加注解的不会导出。
public class OrderExcelBO extends BaseRowModel {@ExcelProperty(value = {"订单ID"}, index = 0)private String id;/*** 订单描述*/@ExcelProperty(value = {"订单描述"}, index = 2)private String description;/*** 订单对应产品id*/@ExcelProperty(value = {"产品ID"}, index = 2)private Integer productId;/*** 支付方式描述，如：apple pay*/@ExcelProperty(value = {"支付方式"}, index = 3)private String payMethod;/*** create_time*/@ExcelProperty(value = {"时间"}, index = 4)private String createTime;/*** update_time*/private String updateTime;/*** 产生订单的用户*/@ExcelProperty(value = {"用户ID"}, index = 5)private Integer userId;/*** 支付状态：0 未支付、1支付成功支付完成、-1支付失败*/@ExcelProperty(value = {"支付状态"}, index = 6)private String status;/*** 订单来源描述，如：ios 安卓*/@ExcelProperty(value = {"手机型号"}, index = 7)private String platform;/*** 订单流水*/@ExcelProperty(value = {"订单流水号"}, index = 8)private String flowNum;/*** 订单金额*/@ExcelProperty(value = {"金额"}, index = 9)private BigDecimal price;// @ExcelProperty(value = {"收据字段"}, index = 10)private String receipt;@ExcelProperty(value = {"APP来源"}, index = 10)private String sources;}复制代码
导出的模板定义好之后，接下来就是一些封装好的工具类的调用
查出我们需要导出的数据；
生成Excel文件名和sheet名称；
直接调用封装好的工具类导出文件即可；
我们来看下导出的效果
如果你的表头比较复杂，那么根据需求，你也可自行定义，例如如下这种复杂的表头，应该如何设置
首先要修改模板类，如果合并的单元格最大为2，那么所有的表格都需要设置为2，不合并的单元格用空字符串填充，需要合并的单元格将合并部分写上相同的名称，并且排列的序号要连续，不能分开。
我们来看下导出的效果，这样就可以满足我们平时开发需要的excel导出功能。简单易上手。
工具类：
import com.alibaba.excel.context.AnalysisContext;import com.alibaba.excel.event.AnalysisEventListener;import java.util.ArrayList;import java.util.List;public class ExcelListener extends AnalysisEventListener {/*** 自定义用于暂时存储data。* 可以通过实例获取该值*/private List<Object> datas = new ArrayList<>();/*** 通过 AnalysisContext 对象还可以获取当前 sheet，当前行等数据*/@Overridepublic void invoke(Object object, AnalysisContext context) {//数据存储到list，供批量处理，或后续自己业务逻辑处理。datas.add(object);//根据业务自行 do somethingdoSomething();/*如数据过大，可以进行定量分批处理if(datas.size()<=100){datas.add(object);}else {doSomething();datas = new ArrayList<Object>();}*/}/*** 根据业务自行实现该方法*/private void doSomething() {}@Overridepublic void doAfterAllAnalysed(AnalysisContext context) {/*datas.clear();解析结束销毁不用的资源*/}public List<Object> getDatas() {return datas;}public void setDatas(List<Object> datas) {this.datas = datas;}}复制代码
import com.alibaba.excel.ExcelReader;import com.alibaba.excel.ExcelWriter;import com.alibaba.excel.metadata.BaseRowModel;import com.alibaba.excel.metadata.Font;import com.alibaba.excel.metadata.Sheet;import com.alibaba.excel.metadata.TableStyle;import com.alibaba.excel.support.ExcelTypeEnum;import com.mochu.exception.ExcelException;import org.apache.poi.poifs.filesystem.FileMagic;import org.apache.poi.ss.usermodel.IndexedColors;import org.springframework.web.multipart.MultipartFile;import javax.servlet.http.HttpServletResponse;import java.io.BufferedInputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.util.List;public class ExcelUtil {/*** 读取 Excel(多个 sheet)** @param excel 文件* @param rowModel 实体类映射，继承 BaseRowModel 类* @return Excel 数据 list*/public static List<Object> readExcel(MultipartFile excel, BaseRowModel rowModel) {ExcelListener excelListener = new ExcelListener();ExcelReader reader = getReader(excel, excelListener);if (reader == null) {return null;}for (Sheet sheet : reader.getSheets()) {if (rowModel != null) {sheet.setClazz(rowModel.getClass());}reader.read(sheet);}return excelListener.getDatas();}/*** 读取某个 sheet 的 Excel** @param excel 文件* @param rowModel 实体类映射，继承 BaseRowModel 类* @param sheetNo sheet 的序号 从1开始* @return Excel 数据 list*/public static List<Object> readExcel(MultipartFile excel, BaseRowModel rowModel, int sheetNo) {return readExcel(excel, rowModel, sheetNo, 1);}/*** 读取某个 sheet 的 Excel** @param excel 文件* @param rowModel 实体类映射，继承 BaseRowModel 类* @param sheetNo sheet 的序号 从1开始* @param headLineNum 表头行数，默认为1* @return Excel 数据 list*/public static List<Object> readExcel(MultipartFile excel, BaseRowModel rowModel, int sheetNo, int headLineNum) {ExcelListener excelListener = new ExcelListener();ExcelReader reader = getReader(excel, excelListener);if (reader == null) {return null;}reader.read(new Sheet(sheetNo, headLineNum, rowModel.getClass()));return excelListener.getDatas();}/*** 导出 Excel ：一个 sheet，带表头** @param response HttpServletResponse* @param list 数据 list，每个元素为一个 BaseRowModel* @param fileName 导出的文件名* @param sheetName 导入文件的 sheet 名* @param object 映射实体类，Excel 模型*/public static void writeExcel(HttpServletResponse response, List<? extends BaseRowModel> list, String fileName,String sheetName, BaseRowModel object) {ExcelWriter writer = new ExcelWriter(getOutputStream(fileName, response), ExcelTypeEnum.XLSX);Sheet sheet = new Sheet(1, 0, object.getClass());sheet.setSheetName(sheetName);TableStyle tableStyle = new TableStyle();tableStyle.setTableContentBackGroundColor(IndexedColors.WHITE);Font font = new Font();font.setFontHeightInPoints((short) 9);tableStyle.setTableHeadFont(font);tableStyle.setTableContentFont(font);sheet.setTableStyle(tableStyle);writer.write(list, sheet);writer.finish();}/*** 导出 Excel ：多个 sheet，带表头** @param response HttpServletResponse* @param list 数据 list，每个元素为一个 BaseRowModel* @param fileName 导出的文件名* @param sheetName 导入文件的 sheet 名* @param object 映射实体类，Excel 模型*/public static ExcelWriterFactory writeExcelWithSheets(HttpServletResponse response,List<? extends BaseRowModel> list, String fileName,String sheetName, BaseRowModel object) {ExcelWriterFactory writer = new ExcelWriterFactory(getOutputStream(fileName, response), ExcelTypeEnum.XLSX);Sheet sheet = new Sheet(1, 0, object.getClass());sheet.setSheetName(sheetName);sheet.setTableStyle(getTableStyle());writer.write(list, sheet);return writer;}/*** 导出融资还款情况表** @param response* @param list* @param fileName* @param sheetName* @param object*/public static void writeFinanceRepayment(HttpServletResponse response, List<? extends BaseRowModel> list,String fileName, String sheetName, BaseRowModel object) {ExcelWriter writer = new ExcelWriter(getOutputStream(fileName, response), ExcelTypeEnum.XLSX);Sheet sheet = new Sheet(1, 0, object.getClass());sheet.setSheetName(sheetName);sheet.setTableStyle(getTableStyle());writer.write(list, sheet);for (int i = 1; i <= list.size(); i += 4) {writer.merge(i, i + 3, 0, 0);writer.merge(i, i + 3, 1, 1);}writer.finish();}/*** 导出文件时为Writer生成OutputStream*/private static OutputStream getOutputStream(String fileName, HttpServletResponse response) {//创建本地文件fileName = fileName + ".xls";try {fileName = new String(fileName.getBytes(), "ISO-8859-1");response.addHeader("Content-Disposition", "filename=" + fileName);return response.getOutputStream();} catch (Exception e) {throw new ExcelException("导出异常！");}}/*** 返回 ExcelReader** @param excel 需要解析的 Excel 文件* @param excelListener new ExcelListener()*/private static ExcelReader getReader(MultipartFile excel, ExcelListener excelListener) {String filename = excel.getOriginalFilename();if (filename == null || (!filename.toLowerCase().endsWith(".xls") && !filename.toLowerCase().endsWith(".xlsx"))) {throw new ExcelException("文件格式错误！");}InputStream inputStream;try {inputStream = new BufferedInputStream(excel.getInputStream());return new ExcelReader(inputStream, null, excelListener, false);} catch (IOException e) {e.printStackTrace();}return null;}/*** 资金收支导出 Excel ：一个 sheet，带表头** @param response HttpServletResponse* @param list 数据 list，每个元素为一个 BaseRowModel* @param fileName 导出的文件名* @param sheetName 导入文件的 sheet 名* @param object 映射实体类，Excel 模型*/public static void exportFundBudgetExcel(HttpServletResponse response, List<? extends BaseRowModel> list,String fileName, String sheetName, BaseRowModel object) throws IOException {ExcelWriter writer = new ExcelWriter(getOutputStream(fileName, response), ExcelTypeEnum.XLSX);Sheet sheet = new Sheet(1, 0, object.getClass());sheet.setSheetName(sheetName);sheet.setTableStyle(getTableStyle());writer.write(list, sheet);writer.merge(2, 3, 0, 0);writer.merge(4, 13, 0, 0);writer.merge(14, 14, 0, 1);writer.finish();}/*** 读取Excel表格数据，封装成实体** @param inputStream* @param clazz* @param sheetNo* @param headLineMun* @return*/public static Object readExcel(InputStream inputStream, Class<? extends BaseRowModel> clazz, Integer sheetNo,Integer headLineMun) {if (null == inputStream) {throw new NullPointerException("the inputStream is null!");}ExcelListener listener = new ExcelListener();ExcelReader reader = new ExcelReader(inputStream, valueOf(inputStream), null, listener);reader.read(new Sheet(sheetNo, headLineMun, clazz));return listener.getDatas();}/*** 根据输入流，判断为xls还是xlsx，该方法原本存在于easyexcel 1.1.0 的ExcelTypeEnum中。*/public static ExcelTypeEnum valueOf(InputStream inputStream) {try {FileMagic fileMagic = FileMagic.valueOf(inputStream);if (FileMagic.OLE2.equals(fileMagic)) {return ExcelTypeEnum.XLS;}if (FileMagic.OOXML.equals(fileMagic)) {return ExcelTypeEnum.XLSX;}throw new ExcelException("excelTypeEnum can not null");} catch (IOException e) {throw new RuntimeException(e);}}/*** 设置全局样式** @return*/private static TableStyle getTableStyle() {TableStyle tableStyle = new TableStyle();tableStyle.setTableContentBackGroundColor(IndexedColors.WHITE);Font font = new Font();font.setBold(true);font.setFontHeightInPoints((short) 9);tableStyle.setTableHeadFont(font);Font fontContent = new Font();fontContent.setFontHeightInPoints((short) 9);tableStyle.setTableContentFont(fontContent);return tableStyle;}}复制代码
import com.alibaba.excel.ExcelWriter;import com.alibaba.excel.metadata.BaseRowModel;import com.alibaba.excel.metadata.Sheet;import com.alibaba.excel.support.ExcelTypeEnum;import java.io.IOException;import java.io.OutputStream;import java.util.List;public class ExcelWriterFactory extends ExcelWriter {private OutputStream outputStream;private int sheetNo = 1;public ExcelWriterFactory(OutputStream outputStream, ExcelTypeEnum typeEnum) {super(outputStream, typeEnum);this.outputStream = outputStream;}public ExcelWriterFactory write(List<? extends BaseRowModel> list, String sheetName, BaseRowModel object) {this.sheetNo++;try {Sheet sheet = new Sheet(sheetNo, 0, object.getClass());sheet.setSheetName(sheetName);this.write(list, sheet);}catch(Exception ex) {ex.printStackTrace();try {outputStream.flush();}catch(IOException e) {e.printStackTrace();}}return this;}@Overridepublic void finish() {super.finish();try {outputStream.flush();}catch(IOException e) {e.printStackTrace();}}}复制代码
由于篇幅原因，如果需要分享Excel导入功能，下方留言。
作者：一个程序员的成长
链接：https://juejin.im/post/5d9de4415188252a923a878f
来源：掘金
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