POI实现excel的导入导出-[采用反射实现的版本]
前段时间学习了POI实现excel的导入导出-[未采用反射实现的版本]的文章，觉得不采用反射实现非常不合理，在祥哥【我眼中的大佬】的指导下实现了POI实现excel的导入导出-[采用反射实现的版本]的实现。
A、具体的要点如下:
1、采用泛型，增加代码的灵活性和可扩展性；
2、使用适配器模式；
3、使用反射自动执行对应字段的方法；
4、绑定字段的值和表头文字【采用linkedhashmap()】实现；
B、代码
ExcelVO.java
package com.spring.boot.gp4zj.util;
import java.util.List;
import java.util.Map;
/**
* excel导入导出相关的必须信息;
*
* @author xdsm
*
*/
public class ExcelVO {
// 表头列表;
Map workBookHeaderFields = null;
// excel中的数据值对象;
List workBookVos = null;
// 泛型数据对象;
T clazzRes = null;
public List getWorkBookVos() {
return workBookVos;
}
public void setWorkBookVos(List workBookVos) {
this.workBookVos = workBookVos;
}
public Map getWorkBookHeaderFields() {
return workBookHeaderFields;
}
public void setWorkBookHeaderFields(Map workBookHeaderFields) {
this.workBookHeaderFields = workBookHeaderFields;
}
public T getClazzRes() {
return clazzRes;
}
public void setClazzRes(T clazzRes) {
this.clazzRes = clazzRes;
}
}
POIUtils.java
package com.spring.boot.gp4zj.util;
import java.io.FileInputStream;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import com.spring.boot.gp4zj.model.AttenceDetail;
import com.spring.boot.gp4zj.model.ExcelVOMapper;
/**
* Excel操作相关的工具类;
*
* @author:JunZhou
* @Company:LongZheng
* @Email:[email protected]
* @2018年1月16日@下午3:19:25
*/
public class POIUtils2 {
public static void main(String[] args) throws Exception {
/*
* AttenceDetail clazzRes = new AttenceDetail(); // 测试数据;
* ExcelVO excelVo = new ExcelVO();
* excelVo.setClazzRes(clazzRes);
*
* @SuppressWarnings("unused") List workBookHeaderFields = new
* ArrayList(); final Map HEADER_FIELDS = new
* LinkedHashMap(); HEADER_FIELDS.put("考勤日期",
* "attencedTime"); HEADER_FIELDS.put("考勤名称", "attencerName");
* HEADER_FIELDS.put("员工编码", "attencerCode"); HEADER_FIELDS.put("出勤时长",
* "workTimeLen"); HEADER_FIELDS.put("加班时长", "extraTimeLen");
* HEADER_FIELDS.put("合计出勤时长", "totalTimeLen");
* HEADER_FIELDS.put("报工单位", "applyCompany"); HEADER_FIELDS.put("结算单位",
* "payCompany"); HEADER_FIELDS.put("创建人", "creator");
* HEADER_FIELDS.put("出勤人天", "workDayNum"); HEADER_FIELDS.put("加班人天",
* "extraDayNum"); HEADER_FIELDS.put("合计人天", "totalDayNum");
* HEADER_FIELDS.put("是否删除汇总表", "isDelGather");
* HEADER_FIELDS.put("是否确认", "isConfirmed"); HEADER_FIELDS.put("创建时间",
* "createTime"); HEADER_FIELDS.put("修改时间", "editTime"); // 生成测试数据;
* excelVo.setWorkBookHeaderFields(HEADER_FIELDS); List
* workBookVos = TestDataGenerater.attenceDetailTestDatasGenerater(2);
* excelVo.setWorkBookVos(workBookVos); createExcel(excelVo);
*/
String excelPath = "C:/Users/xdsm/Desktop/Excel-900500219.xls";
AttenceDetail attenceDetailClazz = new AttenceDetail();
List attenctDetailList = readExcel(excelPath, attenceDetailClazz);
for (AttenceDetail attenceDetail : attenctDetailList) {
System.out.println(attenceDetail);
}
}
/**
* 创建Excel
*
* @param
*
* @param list
* 数据
*/
@SuppressWarnings({ "unchecked", "unused" })
public static HSSFWorkbook createExcel(ExcelVO excelVo) {
@SuppressWarnings("rawtypes")
Class clazz = excelVo.getClazzRes().getClass();
// 表头信息列表;
List workBookHeaderFields = new ArrayList();
Map headerFields = excelVo.getWorkBookHeaderFields();
// 表格数据信息列表;
List dataList = excelVo.getWorkBookVos();
// 创建一个Excel文件
HSSFWorkbook workbook = new HSSFWorkbook();
// 创建一个工作表
HSSFSheet sheet = workbook.createSheet("考勤明细表");
// 添加表头行
HSSFRow hssfRow = sheet.createRow(0);
// 设置单元格格式居中
HSSFCellStyle cellStyle = workbook.createCellStyle();
cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
// 添加表头内容
// -------第一行第0-2列---------
// 设置表头的相关信息;
int headTitleIndex = 0;
HSSFCell headCell = null;// 此处使用同一个引用对象，可以节省内存;
for (Entry vo : headerFields.entrySet()) {
// 表头的名称字段;
if (headTitleIndex == 0) {
headCell = hssfRow.createCell(headTitleIndex);
headCell.setCellValue(vo.getKey());
headCell.setCellStyle(cellStyle);
} else {
headCell = hssfRow.createCell(headTitleIndex);
headCell.setCellValue(vo.getKey());
headCell.setCellStyle(cellStyle);
}
headTitleIndex++;
}
// 填充数据到工作簿;
for (int i = 0; i < dataList.size(); i++) {
// 创建数据行;
hssfRow = sheet.createRow((int) i + 1);
T attenceDetail = dataList.get(i);
// 创建单元格，并设置值
int fieldVoIndex = 0;
HSSFCell cell = null;// 此处使用同一个引用对象，可以节省内存;
for (Entry vo : headerFields.entrySet()) {
// 字段值取值器;
String fieldVoGetter = "get" + (vo.getValue()).substring(0, 1).toUpperCase()
+ (vo.getValue()).substring(1);
cell = hssfRow.createCell(fieldVoIndex);
// TODO Auto-generated
Method method;
try {
String invokeResultStr = null;
method = clazz.getMethod(fieldVoGetter);
Object methodResult = method.invoke(attenceDetail);
if (methodResult != null) {
invokeResultStr = methodResult.toString();
}
cell.setCellValue(invokeResultStr);
cell.setCellStyle(cellStyle);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// method.invoke(clazz.newInstance());
fieldVoIndex++;
}
}
return workbook;
}
/**
* 接收上传的excel并读取其中的信息;
*
* @throws IllegalAccessException
* @throws Exception
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
public static List readExcel(String excelPath, T clazzRes) throws Exception {
Class clazz = clazzRes.getClass();
List list = new ArrayList();
HSSFWorkbook workbook = null;
try {
// 读取Excel文件
InputStream inputStream = new FileInputStream(excelPath);
workbook = new HSSFWorkbook(inputStream);
inputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
// 循环工作表
for (int numSheet = 0; numSheet < workbook.getNumberOfSheets(); numSheet++) {
HSSFSheet hssfSheet = workbook.getSheetAt(numSheet);
if (hssfSheet == null) {
continue;
}
// 循环行
for (int rowNum = 1; rowNum < hssfSheet.getLastRowNum(); rowNum++) {
HSSFRow hssfRow = hssfSheet.getRow(rowNum);
if (hssfRow == null) {
continue;
}
// 填充数据到行;
Map HEADER_FIELDS = ExcelVOMapper.getAttenceDetailMapper();
HSSFCell cell = null;// 公用cell，节省内存的开销;
// 每行的数据对象;
T dataVo = (T) clazz.newInstance();
int fieldVoIndex = 0;
for (Entry vo : HEADER_FIELDS.entrySet()) {
// 字段值取值器;
String fieldVoSetter = "set" + (vo.getValue()).substring(0, 1).toUpperCase()
+ (vo.getValue()).substring(1);
// TODO Auto-generated
Method method;
try {
cell = hssfRow.getCell(fieldVoIndex);
if (cell == null) {
continue;
}
method = clazz.getMethod(fieldVoSetter, String.class);
String cellValue = cell.getStringCellValue();
/*
* if(cellValue==null||"".equals(cellValue)){ // 空数据列测试;
* if (fieldVoIndex == 1) { throw new
* MyException("员工编码不能为空"); } }
*/
// System.out.println(cellValue);
method.invoke(dataVo, cellValue);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
fieldVoIndex++;
}
list.add(dataVo);
}
}
return list;
}
/**
* 获取指定数据类型的所有声明字段;
*
* @param dataObj:泛型对象;
* @return:返回字段列表【String】;
*/
public static List getAllFields(T dataObj) {
Class dataObjClazz = dataObj.getClass();
Field[] fields = dataObjClazz.getDeclaredFields();
List fieldsList = new ArrayList();
for (int i = 0; i < fields.length; i++) {
String fieldStr = fields[i].toString();
String realFieldStr = fieldStr.substring(fieldStr.lastIndexOf(".") + 1);
fieldsList.add(realFieldStr);
}
return fieldsList;
}
/**
* 获取对象中的所有已声明的方法名;
*
* @param dataObj:泛型对象;
* @return:返回方法列表【String】;
*/
public static List getAllMethods(T dataObj) {
List methodsList = new ArrayList();
Class dataObjClazz = dataObj.getClass();
Method[] methods = dataObjClazz.getDeclaredMethods();
for (int i = 0; i < methods.length; i++) {
String fieldStr = methods[i].toString();
if (fieldStr.contains("get")) {
String realFieldStr = fieldStr.substring(fieldStr.lastIndexOf(".") + 1, fieldStr.lastIndexOf("("));
methodsList.add(realFieldStr);
}
}
return methodsList;
}
/**
* 获取对象中的所有已声明的方法名;
*
* @param dataObj:泛型对象;
* @return:返回方法列表【String】;
*/
public static List getAllSetMethods(T dataObj) {
List methodsList = new ArrayList();
@SuppressWarnings("unused")
Class dataObjClazz = dataObj.getClass();
List methods = getAllFields(dataObj);
for (int i = 0; i < methods.size(); i++) {
String fieldStr = methods.get(i).toString();
String methodName = "set" + fieldStr.substring(0, 1).toUpperCase() + fieldStr.substring(1);
methodsList.add(methodName);
}
return methodsList;
}
}
C、使用要点
1、本工具类的使用前提是所有的字段均采用驼峰命名方式，且前两个字母为小写【因为eclipse自动生成的getter和setter会根据前两个字母进行自适应处理，并非固定模式】
2、本工具类并未对导入数据进行全面的非空或者类型等校验，具体的校验可自行添加。
3、本工具类因为采用的是反射是想，因此执行效率较低;
D、参考文章.
设计模式–观察者模式初探和java Observable模式
EasyPoi教程V1.0