版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/linfujian1999/article/details/86594177
关于excel的操作工具网上实在太多,但有两方面原因值得自己写一个:1)简单的导入导出功能的案例大同小异,自己写一个也浪费不了多少时间,2)成熟的git工具类功能过于臃肿,我仅仅需要个导入导出你让我依赖你一个完整的package?
一、核心工具类代码:
package com.roboadvisor.platform.util.excelUtil;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.formula.functions.T;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.util.IOUtils;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.multipart.MultipartFile;
import com.roboadvisor.platform.entity.excelEntity.ExcelFiled;
/**
* excel解析工具
* @author fujian
*
*/
public class ExcelUtil {
/**
* 根据clazz定义的column解析excel文件
* @param excel
* @param clazz
*/
public static <T> List<T> parse(MultipartFile excel, Class<T> clazz) {
try {
File tmpFile = File.createTempFile(excel.getOriginalFilename().substring(0, excel.getOriginalFilename().lastIndexOf(".")), excel.getOriginalFilename().substring(excel.getOriginalFilename().lastIndexOf(".")+1));
excel.transferTo(tmpFile);
Workbook workbook = getWorkBook(tmpFile);
Sheet sheet = workbook.getSheetAt(0);
return parseSheet(sheet, clazz);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
private static Workbook getWorkBook(File file) {
FileInputStream fis = null;
try {
fis = new FileInputStream(file);
if(file.getName().endsWith("xls")) {
return new HSSFWorkbook(fis);
}
if(file.getName().endsWith("xlsx")) {
return new XSSFWorkbook(fis);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
IOUtils.closeQuietly(fis);
}
return null;
}
private static <T> List<T> parseSheet(Sheet sheet, Class<T> clazz) {
List<T> result = new ArrayList<>();
Map<String, Integer> field2ColNum = new HashMap<>();
Field[] fields = clazz.getDeclaredFields();
for(Field field : fields) {
if(!field.isAccessible()) {
field.setAccessible(true);
}
ExcelFiled anno = field.getDeclaredAnnotation(ExcelFiled.class);
if(null != anno) {
field2ColNum.put(field.getName(), anno.columnNum());
}
}
for(int rowNum =1; rowNum<sheet.getLastRowNum(); rowNum++) {
Row row = sheet.getRow(rowNum);
try {
T object = clazz.newInstance();
for(String filedName : field2ColNum.keySet()) {
int cellNum = field2ColNum.get(filedName);
Method method = clazz.getDeclaredMethod("set"+filedName.replaceAll("^\\w", String.valueOf(filedName.charAt(0)).toUpperCase()), String.class);
if(CellType.STRING != row.getCell(cellNum).getCellType()) {
method.invoke(object, String.valueOf(row.getCell(cellNum).getNumericCellValue()).replaceAll("\\.\\d+", ""));
} else {
method.invoke(object, row.getCell(cellNum).getStringCellValue());
}
}
result.add(object);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return result;
}
/**
* 将list中的数据写入excel
* @param list
* @return
*/
public static <T> InputStream exportExcel(List<T> list) {
InputStream excel = null;
if(list.isEmpty()) {
return excel;
}
Workbook workbook = new XSSFWorkbook();
Sheet sheet = workbook.createSheet();
Row headerRow = sheet.createRow(0);
Class<?> clazz = list.get(0).getClass();
Map<String, Integer> field2ColNum = new HashMap<>();
Field[] fields = clazz.getDeclaredFields();
for(Field field : fields) {
if(!field.isAccessible()) {
field.setAccessible(true);
}
ExcelFiled anno = field.getDeclaredAnnotation(ExcelFiled.class);
if(null != anno) {
field2ColNum.put(field.getName(), anno.columnNum());
headerRow.createCell(anno.columnNum()).setCellValue(anno.columnName());
}
}
Set<String> fileds = field2ColNum.keySet();
for(int i=0; i<list.size(); i++) {
Row row = sheet.createRow(i+1);
for(String field : fileds) {
try {
Method method = clazz.getDeclaredMethod("get"+field.replaceAll("^\\w", String.valueOf(field.charAt(0)).toUpperCase()));
String object = String.valueOf(method.invoke(list.get(i)));
row.createCell(field2ColNum.get(field)).setCellValue(object);
} catch (Exception e) {
e.printStackTrace();
}
}
}
for(int i=0; i<fields.length; i++) {
sheet.autoSizeColumn(i);
}
try {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
workbook.write(outputStream);
excel = new ByteArrayInputStream(outputStream.toByteArray());
workbook.close();
return excel;
} catch (Exception e) {
e.printStackTrace();
}
return excel;
}
}
二、与excel中内容对应的实体类上需添加的注解如下:
package com.roboadvisor.platform.entity.excelEntity;
import lombok.Getter;
import lombok.Setter;
@Setter
@Getter
public class ExcelEntity {
private String poolId;
@ExcelFiled(columnName="基金代码", columnNum=0)
private String securityId;
@ExcelFiled(columnName="基金名称", columnNum=1)
private String secName;
@ExcelFiled(columnName="产品类型", columnNum=2)
private String secType;
}
columnName为列名称,中文名称
columnNum为列数,0-based
三、service层调用excel工具类
package com.roboadvisor.platform.service;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.compress.utils.IOUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import com.roboadvisor.platform.entity.excelEntity.ExcelEntity;
import com.roboadvisor.platform.mapper.FileImportMapper;
import com.roboadvisor.platform.util.excelUtil.ExcelUtil;
import com.roboadvisor.platform.util.resultEntity.ResultEntity;
import com.roboadvisor.platform.util.resultEntity.ResultStatus;
@Service
public class FileImportService {
@Autowired
private FileImportMapper mapper;
/**
* excel内容导入db
* @param excel
* @return
*/
public ResultEntity<String> importExcel(MultipartFile excel) {
List<ExcelEntity> entities = ExcelUtil.parse(excel, ExcelEntity.class);
mapper.insertList(entities);
return new ResultEntity<>(ResultStatus.OK);
}
/**
* db内容写入excel
* @param entities
* @throws UnsupportedEncodingException
*/
public void exportExcel(HttpServletResponse response) throws UnsupportedEncodingException {
List<ExcelEntity> list = mapper.getFromDB();
InputStream in = ExcelUtil.exportExcel(list);
response.reset();
response.setContentType("multipart/form-data");
response.setCharacterEncoding("UTF-8");
String fielname = URLEncoder.encode("export-excel.xlsx", "UTF-8");
response.setHeader("Content-Disposition", "attachment; filename=" + fielname);
byte[] buffer = new byte[1024];
int length;
try {
while((length = in.read(buffer)) >0) {
response.getOutputStream().write(buffer, 0, length);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
IOUtils.closeQuietly(in);
}
}
}