Alibaba的EasyExcel使用心得
目录
前言:
开发前准备：
1、导入依赖
2、导出实体类
1）常用注解
2）注意内容
3、监听器
ExcelMapper
Handler
4、模板文件
5、测试demo
1）调整单元格样式
2）插入图片
最终效果：
项目实战：
1、读Excel
Controller
Service
ServiceImpl
2、写Excel
Controller
Service
ServiceImpl
前言:
EasyExcel是一个基于Java的简单、省内存的读写Excel的开源项目。在尽可能节约内存的情况下支持读写百M的Excel。easyexcel重写了poi对07版Excel的解析，能够原本一个3M的excel用POI sax依然需要100M左右内存降低到几M，并且再大的excel不会出现内存溢出，03版依赖POI的sax模式。在上层做了模型转换的封装，让使用者更加简单方便。
官网：EasyExcel官方文档 - 基于Java的Excel处理工具 | Easy Excel (alibaba.com)
开发前准备：
1、导入依赖
com.alibaba
easyexcel
2.2.3
2、导出实体类
import com.alibaba.excel.annotation.ExcelIgnore;
import com.alibaba.excel.annotation.ExcelProperty;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import java.util.Date;
@Data
@TableName("user")
public class ExcelUserEntityImport {
private static final long serialVersionUID = 1L;
@ExcelProperty(value = "用户名")
private String username;
@ExcelProperty(value = "密码")
private String password;
@ExcelProperty(value = "手机号")
private String phone;
@ExcelProperty("性别标签")
private Integer sex;
@ExcelProperty({"基础信息","年龄"})
private Integer age;
@ExcelProperty({"基础信息","性别"})
private String gender;
@ExcelProperty(value ={"基础信息","地址"})
private String address;
@ExcelIgnore
//@ExcelProperty(converter = DateConverter.class,value = "生日")
private Date birthday;
//忽略导出字段
@ExcelIgnore
private Long id;
@ExcelIgnore
private String hobby;
@ExcelIgnore
private Date creatTime;
@ExcelIgnore
private Date updateTime;
@ExcelIgnore
private Integer isDeleted;
}
1）常用注解
@ExcelProperty(value = "用户名",index=0) ->导出属性名
@ExcelIgnore ->忽略导出的字段
2）注意内容
如果在@ExcelProperty中不指定index的值，index会默认从0开始排版，如果指定顺序，导出的表格则会按照index顺序进行排版。
3、监听器
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
// 有个很重要的点 UserDataListener 不能被spring管理，要每次读取excel都要new,然后里面用到spring可以构造方法传进去
@Slf4j
public class UserDataListener extends AnalysisEventListener {
private static final Logger LOGGER = LoggerFactory.getLogger(ExcelUserEntityImport.class);
/**
* 每隔5条存储数据库，实际使用中可以3000条，然后清理list ，方便内存回收
*/
private static final int BATCH_COUNT = 100;
/**
* 缓存的数据
*/
private List list = new ArrayList<>(BATCH_COUNT);
@Override
public void invoke(ExcelUserEntityImport data, AnalysisContext analysisContext) {
LOGGER.info("解析到一条数据:{}", JSON.toJSONString(data));
String gender = data.getGender();
Integer sex = getSexByGender(gender);
data.setSex(sex);
/**
* 自己要完成的逻辑
* 进行自己功能的实现
*/
list.add(data);
if (list.size() >= BATCH_COUNT) {
// saveData();
// 存储完成清理 list
list = new ArrayList<>(BATCH_COUNT);
}
}
public Integer getSexByGender(String gender) {
switch (gender){
case "男":
return 1;
case "女":
return 2;
case "未知":
return 3;
default:
throw new RuntimeException("性别异常");
}
}
@Override
public void doAfterAllAnalysed(AnalysisContext analysisContext) {
LOGGER.info("所有数据解析完成！");
}
/**
* 自己要完成的逻辑
* 进行自己功能的实现
*/
public void doSome(){}
} ExcelMapper
public interface ExcelMapper extends BaseMapper {
} Handler
import com.alibaba.excel.write.handler.SheetWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteWorkbookHolder;
import org.apache.poi.ss.usermodel.DataValidation;
import org.apache.poi.ss.usermodel.DataValidationConstraint;
import org.apache.poi.ss.usermodel.DataValidationHelper;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddressList;
import java.util.HashMap;
import java.util.Map;
//要在导出时添加到对应的handler中
public class ExcelTemplateHandler implements SheetWriteHandler {
@Override
public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
}
@Override
public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
String[] sexTypes = new String[]{"男", "女", "未知"};
Map mapDropDown = new HashMap<>();
// 3 为导出表格索引，索引冲0开始。 如不在excel导出实体类指定，则按照先后顺序
mapDropDown.put(3, sexTypes);
Sheet sheet = writeSheetHolder.getSheet();
///开始设置下拉框
DataValidationHelper helper = sheet.getDataValidationHelper();//设置下拉框
for (Map.Entry entry : mapDropDown.entrySet()) {
/***起始行、终止行、起始列、终止列**/
CellRangeAddressList addressList = new CellRangeAddressList(1, 1000, entry.getKey(), entry.getKey());
/***设置下拉框数据**/
DataValidationConstraint constraint = helper.createExplicitListConstraint(entry.getValue());
DataValidation dataValidation = helper.createValidation(constraint, addressList);
/*处理Excel兼容性问题
if (dataValidation instanceof XSSFDataValidation) {
dataValidation.setSuppressDropDownArrow(true);
dataValidation.setShowErrorBox(true);
} else {
dataValidation.setSuppressDropDownArrow(false);
}*/
sheet.addValidationData(dataValidation);
}
}
}
4、模板文件
5、测试demo
@Test
@SneakyThrows
public void test() {
/**
* 1、进行模板填充
*/
// 生成Excel路径
String filePath = "a.xlsx";
//模板路径
String templatePath = "temp.xlsx";
ExcelWriter excelWriter = EasyExcel.write(filePath).withTemplate(templatePath).build();
WriteSheet writeSheet = EasyExcel.writerSheet().build();
//代表表格每次都会重新生成新的一行，而不是使用下面的空行。
FillConfig fillConfig = FillConfig.builder().forceNewRow(Boolean.TRUE).build();
// 填充数据
ExcelTemplate template = new ExcelTemplate();
template.setEaddress("河南省xxxx")
.setEbegintime(new Date())
.setEdesc("摸鱼ing")
.setEendtime(new Date())
.setEidcard("41xxxxxxxxxxx")
.setEmajor("电子商务")
.setEmarriage("未婚")
.setEname("小张")
.setEnation("汉")
.setEbirthday(new Date())
.setEpost("天才少女")
.setEgradeationtime(new Date())
.setEschool("xxxx")
.setEsex("女")
.setEworkcom("天庭六部")
.setEsalary(10000000.0)
.setEnative("未知");
//进行字段的填充
excelWriter.fill(template, writeSheet);
//进行模板表格的填充 datal和模板相互对应
//excelWriter.fill(new FillWrapper(template, template, fillConfig, writeSheet);
// 别忘记关闭流
excelWriter.finish();进行测试后发现，单元格相关没有对应格式。
1）调整单元格样式
/**
* 2、进行单元格合并 样式调整
*/
//注意：一定要先把文件创建完后再进行单元格样式设置
FileInputStream inputStream = new FileInputStream(new File(filePath));
XSSFWorkbook workbook = new XSSFWorkbook(inputStream);
XSSFSheet sheet = workbook.getSheetAt(0);
// 合并列 列和行均为0开始
sheet.addMergedRegion(new CellRangeAddress(16, 16, 1, 2));
sheet.addMergedRegion(new CellRangeAddress(16, 16, 3, 4));
sheet.addMergedRegion(new CellRangeAddress(16, 16, 5, 6));
sheet.addMergedRegion(new CellRangeAddress(16, 16, 7, 8));
sheet.addMergedRegion(new CellRangeAddress(16, 16, 9, 10));
sheet.addMergedRegion(new CellRangeAddress(16, 16, 11, 13));
//进行下边框的设置
RegionUtil.setBorderBottom(BorderStyle.THIN,new CellRangeAddress(15, 15, 1, 13),sheet);2）插入图片
/**
* 3、插入图片
*/
// 转换成流
ByteArrayOutputStream byteArrayOut = new ByteArrayOutputStream();
BufferedImage bufferImg = ImageIO.read(new File("note.jpg"));
ImageIO.write(bufferImg, "jpg", byteArrayOut);
XSSFDrawing patriarch = sheet.createDrawingPatriarch();
/**
* new XSSFClientAnchor(0, 0, 0, 0, (short) 11, 2, (short) 12, 6);
* 前4个参数是偏移量，设置为0即可 row1为起始行 row2结束行 前到后不到 (short) 11为起始列 (short) 12 为结束列
* 设置好这些参数就能在指定位置插入图片
*/
XSSFClientAnchor anchor = new XSSFClientAnchor(0, 0, 0, 0, (short) 11, 3, (short) 14, 14);
anchor.setAnchorType(ClientAnchor.AnchorType.DONT_MOVE_AND_RESIZE);
patriarch.createPicture(anchor, workbook.addPicture(byteArrayOut.toByteArray(), HSSFWorkbook.PICTURE_TYPE_JPEG));
String mergeExcelPath="merge.xlsx";
FileOutputStream outputStream = new FileOutputStream(mergeExcelPath);
workbook.write(outputStream);
outputStream.flush();最终效果：
项目实战：
1、读Excel
Controller
@GetMapping("/exportExcel")
@ApiOperation(value = "批量导出基础字段文件", notes = "导出file")
public void exportExcel(HttpServletResponse response, @RequestParam String ids) throws IOException {
List list = Func.toLongList(ids);
userService.exportExcel(response, list);
} Service
void exportExcel(HttpServletResponse response, List list); ServiceImpl
@SneakyThrows
@Override
public void exportExcel(HttpServletResponse response, List list) {
//导出所需数据(自己要的数据)
List userList = baseMapper.selectBatchIds(list);
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
String fileName = URLEncoder.encode("用户数据", "UTF-8");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
EasyExcel.write(response.getOutputStream(), ExcelUserEntityImport.class)
.registerConverter(new LongStringConverter())
//样式的处理类 需要就注册进来.registerWriteHandler(new ExcelTemplateHandler())
.registerWriteHandler(new LongestMatchColumnWidthStyleStrategy())
.sheet("数据导出").doWrite(userList);
} 2、写Excel
Controller
/**
* 上传文件
* @param file 文件
*/
@PostMapping("/uploadFile")
@ApiOperation(value = "上传文件", notes = "传入file")
public R uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
return userService.uploadFile(file);
}Service
R uploadFile(MultipartFile file);ServiceImpl
@Override
public R uploadFile(MultipartFile file) {
List excelList=null;
try {
excelList = read(file.getInputStream(), ExcelUserEntityImport.class, new UserDataListener()).sheet().doReadSync();
} catch (IOException e) {
e.printStackTrace();
}
excelService.saveBatch(excelList);
return R.ok();
} 这样下来就大功告成了！