Foreword:
The code can be copied and pasted. The main functions include Excel template download, Excel-based data import, and Excel data export.
Just modify some details according to the actual situation. The results will be displayed at the end. You can check the results first to see if they are what you want.
One minute on stage and 60 seconds off stage. If you don’t like it, don’t complain.
If you find it useful, please give it a like and follow.
Create a new SpringBoot project and introduce the following dependencies
Note: This dependency has been integrated with poi and poi-ooxm and does not need to be introduced separately.
<!-- EasyExcel -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>2.2.7</version>
</dependency>
Data import and export execution principles and ideas:
Client logic:
-
data import
用户先下载模板，根据模板填入数据，然后点击上传； -
Data output
用户在界面选择需要导出的数据（导出条件），点击导出。
Backend development logic:
-
Template download
利用easyExcel生成文件，然后将文件放进响应流中，同时设置响应头为文件下载，浏览器收到响应之后，回去解析流中的内容，然后进行下载。 -
File Upload
用在填写好Excel内容之后，会以文件上传的形式，将文件上传到服务端，此时，我们只需要利用EasyExcel将文件流中的数据读出来即可。 -
Data output
后台在接收到用户的数据导出请求之后，会根据请求中的筛选条件，查询对应数据，再将对应的数据填充进对应的导出模板中，以流的形式响应给浏览器。其实和模板下载的差不错，只是模板下载没有数据，数据导出有数据而已。
Code implementation
Note: The following code is compiled by me according to the specific business. There may be shortcomings. Welcome to give me advice!
Drop-down box strategy
If there is no such requirement, this type can be omitted.
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.*;
import org.apache.poi.ss.util.CellRangeAddressList;
import java.util.Map;
import java.util.TreeMap;
/**
* 这个类的作用主要是给列增加下拉框
* 主要是为了方便用户填写数据
*/
public class CustomSheetWriteHandler implements SheetWriteHandler {
/**
* 存放下拉内容的集合
* key为列的下标， value为下拉内容数组
*/
private final Map<Integer, String[]> map = new TreeMap<>();
/**
* 工作簿下标，从0开始
*/
private int index = 0;
/**
* 给多少行添加下拉框，这里默认给2000行
*/
private final int batchSize = 2000;
@Override
public void beforeSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
}
/**
* 宝藏在此：如果下拉框内容总的长度超过255，会导致Cell有下拉框，但是下拉内容显示不了，
* 这时我们可以新建一个sheet，将其隐藏，然后将里面的内容引用到我们的下拉框列就可以。
* 值得细品
* @param writeWorkbookHolder
* @param writeSheetHolder
*/
@Override
public void afterSheetCreate(WriteWorkbookHolder writeWorkbookHolder, WriteSheetHolder writeSheetHolder) {
// excel下标从0开始，这里第二列的下拉选择内容
map.put(1, new String[]{
"下拉内容一", "下拉内容二"});
// excel下标从0开始，这里第三列的下拉选择内容
map.put(3, new String[]{
"北京市", "上海市", "重庆市", "天津市"});
DataValidationHelper helper = writeSheetHolder.getSheet().getDataValidationHelper();
map.forEach((k, v) -> {
// 创建sheet，突破下拉框255的限制
// 获取一个workbook
Workbook workbook = writeWorkbookHolder.getWorkbook();
// 定义sheet的名称
String sheetName = "sheet" + k;
// 1.创建一个隐藏的sheet 名称为 proviceSheet
Sheet proviceSheet = workbook.createSheet(sheetName);
// 从第二个工作簿开始隐藏
this.index++;
// 设置隐藏
workbook.setSheetHidden(this.index, true);
// 2.循环赋值（为了防止下拉框的行数与隐藏域的行数相对应，将隐藏域加到结束行之后）
for (int i = 0, length = v.length; i < length; i++) {
// i:表示你开始的行数 0表示你开始的列数
proviceSheet.createRow(i).createCell(0).setCellValue(v[i]);
}
Name category1Name = workbook.createName();
category1Name.setNameName(sheetName);
// 4 $A$1:$A$N代表 以A列1行开始获取N行下拉数据
category1Name.setRefersToFormula(sheetName + "!$A$1:$A$" + (v.length));
// 5 将刚才设置的sheet引用到你的下拉列表中,1表示从行的序号1开始（开始行，通常行的序号为0的行是表头），50表示行的序号50（结束行），表示从行的序号1到50，k表示开始列序号和结束列序号
CellRangeAddressList addressList = new CellRangeAddressList(1, batchSize, k, k);
DataValidationConstraint constraint8 = helper.createFormulaListConstraint(sheetName);
DataValidation dataValidation3 = helper.createValidation(constraint8, addressList);
// 阻止输入非下拉选项的值
dataValidation3.setErrorStyle(DataValidation.ErrorStyle.STOP);
dataValidation3.setShowErrorBox(true);
dataValidation3.setSuppressDropDownArrow(true);
dataValidation3.createErrorBox("提示", "此值与单元格定义格式不一致");
// validation.createPromptBox("填写说明：","填写内容只能为下拉数据集中的单位，其他单位将会导致无法入仓");
writeSheetHolder.getSheet().addValidationData(dataValidation3);
});
}
}
Annotation strategy
Add annotation to the table header. If you don’t have this requirement, you don’t need to do it
import com.alibaba.excel.write.handler.RowWriteHandler;
import com.alibaba.excel.write.metadata.holder.WriteSheetHolder;
import com.alibaba.excel.write.metadata.holder.WriteTableHolder;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.ss.usermodel.Comment;
import org.apache.poi.ss.usermodel.Drawing;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFClientAnchor;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
/**
* 自定义拦截器.新增注释,第一行头加批注
* 这个类的作用主要是给表头添加批注
*/
@Slf4j
public class CommentWriteHandler implements RowWriteHandler {
@Override
public void beforeRowCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Integer rowIndex, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterRowCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {
}
@Override
public void afterRowDispose(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, Row row, Integer relativeRowIndex, Boolean isHead) {
Sheet sheet = writeSheetHolder.getSheet();
Drawing<?> drawingPatriarch = sheet.createDrawingPatriarch();
// 在第一行 第二列创建一个批注
Comment comment1 =
drawingPatriarch.createCellComment(new XSSFClientAnchor(0, 0, 0, 0, (short)0, 0, (short)1, 1));
// 输入批注信息
comment1.setString(new XSSFRichTextString("批注1"));
// 将批注添加到单元格对象中
sheet.getRow(0).getCell(0).setCellComment(comment1);
Comment comment2 =
drawingPatriarch.createCellComment(new XSSFClientAnchor(0, 0, 0, 0, (short)1, 0, (short)2, 1));
// 输入批注信息
comment2.setString(new XSSFRichTextString("批注2"));
// 将批注添加到单元格对象中
sheet.getRow(0).getCell(1).setCellComment(comment2);
Comment comment3 =
drawingPatriarch.createCellComment(new XSSFClientAnchor(0, 0, 0, 0, (short)2, 0, (short)3, 1));
// 输入批注信息
comment3.setString(new XSSFRichTextString("批注3"));
// 将批注添加到单元格对象中
sheet.getRow(0).getCell(2).setCellComment(comment3);
}
}
Data reading monitoring
When importing data, the program parses and reads the data, it is necessary! ! !
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.Setter;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
/**
* Excel数据解析监听器， 数据解析方法异步执行
* @param <T> Excel中数据的类型
*/
@Getter
@Setter
@NoArgsConstructor
public class ExcelListener<T> extends AnalysisEventListener<T> {
// 加入一个判断标签，判断数据是否已经读取完
private volatile boolean retryLock = false;
// 解析完成后的数据集合, 监听对象初始化之后，立即初始化集合对象
private final List<T> dataList = new ArrayList<>();
// 每次最多导入条数
private final int batchSize = 2000;
/**
* 获取解析后的数据集合， 如果数据还没有被解析完成，会对读取该集合的线程进行阻塞，直到数据读取完成之后，进行解锁。
* 如果一次导入数据超过batchSize条，则以抛异常的形式阻止导入数据
* @return 解析后的数据集合
*/
public List<T> getDataList() {
while (true){
if (retryLock){
if (dataList.size() > batchSize){
// 手动清空数据内存数据，减少内存消耗
dataList.clear();
throw new RuntimeException("一次最多导入"+ batchSize +"条数据");
} else {
return dataList;
}
}
}
}
/**
* Excel每解析一行数据，就会调用一次该方法
* @param data
* one row value. Is is same as {@link AnalysisContext#readRowHolder()}
* @param context
* analysis context
*/
@Override
public void invoke(T data, AnalysisContext context) {
dataList.add(data);
}
/**
* 读取表头内容
* @param headMap 表头部数据
* @param context 数据解析上下文
*/
@Override
public void invokeHeadMap(Map<Integer, String> headMap, AnalysisContext context) {
//System.out.println("表头：" + headMap);
}
/**
* 流中的数据解析完成之后，就会调用此方法
* @param context
*/
@Override
public void doAfterAllAnalysed(AnalysisContext context) {
// 数据解析完成，解锁
retryLock = true;
}
/**
* 解析过程如果发生异常，会调用此方法
* @param exception
* @param context
*/
@Override
public void onException(Exception exception, AnalysisContext context){
throw new RuntimeException("Excel数据异常，请检查或联系管理员！");
}
}
Excel tool class
Encapsulates a unified Excel operation entrance
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.write.metadata.WriteSheet;
import com.alibaba.excel.write.metadata.WriteTable;
import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.metadata.style.WriteFont;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
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.net.URLEncoder;
import java.util.List;
@Slf4j
public class ExcelUtil {
/**
* 导出数据为excel文件
*
* @param filename 文件名称
* @param dataResult 集合内的bean对象类型要与clazz参数一致
* @param clazz 集合内的bean对象类型要与clazz参数一致
* @param response HttpServlet响应对象
*/
public static void export(String filename, List<?> dataResult, Class<?> clazz, HttpServletResponse response) {
response.setStatus(200);
OutputStream outputStream = null;
ExcelWriter excelWriter = null;
try {
if (StringUtils.isBlank(filename)) {
throw new RuntimeException("'filename' 不能为空");
}
String fileName = filename.concat(".xlsx");
response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "utf-8"));
outputStream = response.getOutputStream();
// 根据不同的策略生成不同的ExcelWriter对象
if (dataResult == null){
excelWriter = getTemplateExcelWriter(outputStream);
} else {
excelWriter = getExportExcelWriter(outputStream);
}
WriteTable writeTable = EasyExcel.writerTable(0).head(clazz).needHead(true).build();
WriteSheet writeSheet = EasyExcel.writerSheet(fileName).build();
// 写出数据
excelWriter.write(dataResult, writeSheet, writeTable);
} catch (Exception e) {
log.error("导出excel数据异常：", e);
throw new RuntimeException(e);
} finally {
if (excelWriter != null) {
excelWriter.finish();
}
if (outputStream != null) {
try {
outputStream.flush();
outputStream.close();
} catch (IOException e) {
log.error("导出数据关闭流异常", e);
}
}
}
}
/**
* 根据不同策略生成不同的ExcelWriter对象， 可根据实际情况修改
* @param outputStream 数据输出流
* @return 模板下载ExcelWriter对象
*/
private static ExcelWriter getTemplateExcelWriter(OutputStream outputStream){
return EasyExcel.write(outputStream)
.registerWriteHandler(new CommentWriteHandler()) //增加批注策略
.registerWriteHandler(new CustomSheetWriteHandler()) //增加下拉框策略
.registerWriteHandler(getStyleStrategy()) //字体居中策略
.build();
}
/**
* 根据不同策略生成不同的ExcelWriter对象， 可根据实际情况修改
* @param outputStream 数据输出流
* @return 数据导出ExcelWriter对象
*/
private static ExcelWriter getExportExcelWriter(OutputStream outputStream){
return EasyExcel.write(outputStream)
.registerWriteHandler(getStyleStrategy()) //字体居中策略
.build();
}
/**
* 设置表格内容居中显示策略
* @return
*/
private static HorizontalCellStyleStrategy getStyleStrategy(){
WriteCellStyle headWriteCellStyle = new WriteCellStyle();
//设置背景颜色
headWriteCellStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
//设置头字体
WriteFont headWriteFont = new WriteFont();
headWriteFont.setFontHeightInPoints((short)13);
headWriteFont.setBold(true);
headWriteCellStyle.setWriteFont(headWriteFont);
//设置头居中
headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
// 内容策略
WriteCellStyle writeCellStyle = new WriteCellStyle();
// 设置内容水平居中
writeCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
return new HorizontalCellStyleStrategy(headWriteCellStyle, writeCellStyle);
}
/**
* 根据Excel模板，批量导入数据
* @param file 导入的Excel
* @param clazz 解析的类型
* @return 解析完成的数据
*/
public static List<?> importExcel(MultipartFile file, Class<?> clazz){
if (file == null || file.isEmpty()){
throw new RuntimeException("没有文件或者文件内容为空！");
}
List<Object> dataList = null;
BufferedInputStream ipt = null;
try {
InputStream is = file.getInputStream();
// 用缓冲流对数据流进行包装
ipt = new BufferedInputStream(is);
// 数据解析监听器
ExcelListener<Object> listener = new ExcelListener<>();
// 读取数据
EasyExcel.read(ipt, clazz,listener).sheet().doRead();
// 获取去读完成之后的数据
dataList = listener.getDataList();
} catch (Exception e){
log.error(String.valueOf(e));
throw new RuntimeException("数据导入失败！" + e);
}
return dataList;
}
}
Create an import data template class
It can be understood that this class is an agreement between us and the customer. The program generates the corresponding Excel file based on this template class, and the customer imports the data based on the Excel file. Fill in. Then the user uploads the filled Excel file to our program, and we have to parse and read the data filled in by the user based on this template class.
Based on actual business adjustments, the above tool class will generate the corresponding Excel file based on the provided template.
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.annotation.write.style.ColumnWidth;
import lombok.Data;
import lombok.experimental.Accessors;
import javax.validation.constraints.NotEmpty;
import java.io.Serializable;
/**
* 数据导入的Excel模板实体
*/
@Data
public class ImportExcelVo implements Serializable {
private static final long serialVersionUID = 1L;
@ColumnWidth(20)
@ExcelProperty(value = "公司名称", index = 0)
private String name;
@ColumnWidth(20)
@ExcelProperty(value = "公司联系电话", index = 1)
private String phone;
@ColumnWidth(28)
@ExcelProperty(value = "公司统一社会信用代码", index = 2)
private String creditCode;
@ColumnWidth(15)
@ExcelProperty(value = "区域", index = 3)
private String province;
@ColumnWidth(15)
@ExcelProperty(value = "公司法人", index = 4)
private String legalPerson;
@ExcelProperty(value = "备注", index = 5)
private String remark;
}
Create a data export template
Present the fields that users can see based on this template.
Based on actual business adjustments, the above tool class will generate the corresponding Excel file based on the provided template.
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.annotation.write.style.ColumnWidth;
import lombok.Data;
import lombok.experimental.Accessors;
import java.io.Serializable;
/**
* 资质信息导出实体
*/
@Data // Lombok注解，用于生成getter setter
@Accessors(chain = true) //Lombok注解，链式赋值使用
public class ExportExcelVo implements Serializable {
private static final long serialVersionUID = 1L;
@ColumnWidth(25)
@ExcelProperty(value = "企业名称", index = 0)
private String name;
@ColumnWidth(25)
@ExcelProperty(value = "社会统一信用代码", index = 1)
private String creditCode;
@ColumnWidth(15)
@ExcelProperty(value = "曾用名", index = 2)
private String formerName;
@ColumnWidth(15)
@ExcelProperty(value = "公司法人", index = 3)
private String legalPerson;
@ExcelProperty(value = "区域", index = 4)
private String province;
@ExcelProperty(value = "录入时间", index = 5)
private String createTime;
@ColumnWidth(15)
@ExcelProperty(value = "公司股东", index = 6)
private String stockholder;
@ExcelProperty(value = "企业联系方式", index = 7)
private String contact;
}
Web interface
import lombok.extern.slf4j.Slf4j;
import com.xxx.xxx.domain.vo.ExportExcelVo;
import com.xxx.xxx.domain.vo.ImportExcelVo;
import com.xxx.xxx.util.CommonResponse;
import com.xxx.xxx.util.ExcelUtil;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletResponse;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
/**
* 事件控制器
*/
@Slf4j
@RestController
@RequestMapping("/api/excel")
public class ExcelController {
/**
* excel模板下载
*/
@RequestMapping(value = "/template", method = RequestMethod.GET)
public CommonResponse<String> template(HttpServletResponse response){
String fileName = "导入模板下载" + System.currentTimeMillis();
try {
ExcelUtil.export(fileName, null, ImportExcelVo.class, response);
} catch (Exception e) {
return CommonResponse.error("模板下载失败" + e.getMessage());
}
return CommonResponse.success("模板下载成功！");
}
/**
* Excel批量导入数据
* @param file 导入文件
*/
@RequestMapping(value = "/import", method = RequestMethod.POST)
public CommonResponse<String> importEvents(MultipartFile file){
try {
List<?> list = ExcelUtil.importExcel(file, ImportExcelVo.class);
System.out.println(list);
return CommonResponse.success("数据导入完成");
} catch (Exception e) {
return CommonResponse.error("数据导入失败！" + e.getMessage());
}
}
/**
* excel数据导出
* @param size 导出条数， 也可以是用户需要导出数据的条件
* @return
*/
@RequestMapping(value = "/export", method = RequestMethod.GET)
public CommonResponse<String> export(Long size, HttpServletResponse response){
// 模拟根据条件在数据库查询数据
ArrayList<ExportExcelVo> excelVos = new ArrayList<>();
for (int i = 1; i <= size; i++) {
ExportExcelVo excelVo = new ExportExcelVo();
excelVo.setContact(String.valueOf(10000000000L + i));
excelVo.setName("公司名称" + i);
excelVo.setCreditCode("社会性用代码" + i);
excelVo.setProvince("地区" + i);
excelVo.setLegalPerson("法人" + i);
excelVo.setFormerName("曾用名" + i);
excelVo.setStockholder("投资人" + i);
excelVo.setCreateTime(new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒").format(new Date()));
excelVos.add(excelVo);
}
String fileName = "数据导出" + System.currentTimeMillis();
try {
ExcelUtil.export(fileName, excelVos, ExportExcelVo.class, response);
} catch (Exception e) {
return CommonResponse.error("数据导出成功" + e.getMessage());
}
return CommonResponse.success("数据导出失败！");
}
}
Result display
Template download
The browser accesses the template download interface, and then parses it based on the content returned by the interface
Data import
Fill in the data in the downloaded template
Use PostMan to upload files
Data export
Browser access data export interface
