自己封装的POI + Struts2 实现Excel导出工具包

1、注解

package lml.excel.annotation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * @author MerryGrass
 * 自定义注解
 */

@Retention(RetentionPolicy.RUNTIME)
public @interface PropertyAnnotation
{
	/**
	 * 属性名称描述 （默认值为 "Unknown"）
	 * @return String
	 */
	String PropertyName() default "Unknown";
	
	/**
	 * 属性索引键 （默认值为 "-1"）
	 * @return int
	 */
	int PropertySortKey() default -1;
}

2、接口

/**
 * 
 */
package lml.excel.service;

import java.util.List;


public interface CreateExcel {
	
	/**
	 * 创建一个sheet
	 * @param sheetName
	 * 			sheet名字
	 */
	public void createSheet(String sheetName);
	
	/**
	 * 创建一行	
	 */
	public void createRow();
	
	/**
	 * 创建一个单元格
	 * @param cellNum
	 * 			单元格所属位置
	 */
	public void createCell(int cellNum);
	
	/**
	 * 设置一个单元格内容
	 * @param data
	 * 			单元格内容
	 * @param cellNum
	 * 			单元格所属位置
	 */
	public void setCell(String data, int cellNum);
	
	/**
 	 * 设置标题内容
 	 * @param title
 	 * 			标题
 	 * @return CreateExcel
 	 */
	public CreateExcel setTitle(String title);
	
	/**
	 * 设置表头内容
	 * @return CreateExcel
	 */
	public CreateExcel setHead();
	
	/**
	 * 设置单元格内容
	 * @param datas
	 * 			单元格数据
	 * @return CreateExcel
	 */
	public CreateExcel setCellData(List<?> datas) throws Exception;
}

/**
 * 
 */
package lml.excel.service;

import java.util.List;

public interface ExcelInfo {
	
	
 	/**
 	 * 获取表头数据
 	 * @return String[] 表头数据所组成的数组
 	 */
	public List<String> getHeaders();
	
	/**
	 * 获取有效属性所对应的值
	 * @param obj
	 * 			对象
	 * @param methodName
	 * 			方法名
	 * @return String
	 */
	public String getContent(Object obj, String methodName) throws Exception;
	
}

package lml.excel.service;

import java.io.InputStream;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;


public interface ExcelService {
	
	/**
	 * 获取Excel
	 * @param clazz
	 * 			类名
	 * @param datas
	 * 			数据
	 * @param title
	 * 			标题
	 * @return
	 */
	public InputStream getExcelInputStream(String clazz, List<?> datas, String title,List<String> fieldsName) throws Exception;
	
	/**
	 * 创建Excel
	 * @param clazz
	 * 			类名
	 * @param datas
	 * 			数据
	 * @param title
	 * 			标题
	 * @return
	 */
	public HSSFWorkbook createExcel(String clazz, List<?> datas, String title,List<String> fieldsName) throws Exception;
}

3、实现类

package lml.excel.service.impl;

import java.util.List;

import lml.excel.service.CreateExcel;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.Region;

public class CreateExcelImpl implements CreateExcel {

	private HSSFWorkbook wb = null;
	private HSSFSheet sheet = null;
	private HSSFRow row = null;
	private HSSFCell cell = null;
	private ExcelInfoImpl excelInfo = null;
	private int rowNum = 0; //当前需要创建的行数，初始化为0
	
	/**
	 * 初始化HSSFWorkbook，并默认创建一个sheet
	 * @param className
	 * 			类的全路径
	 */
	public CreateExcelImpl(String className,List<String> fieldsName){
		wb = new HSSFWorkbook();
		createSheet("sheet1");
		excelInfo = new ExcelInfoImpl(className,fieldsName);
	}
	
	/**
	 * 创建一个单元格
	 * @param cellNum
	 * 			单元格所属位置
	 */
	public void createCell(int cellNum) {
		cell = row.createCell((short)cellNum);

	}

	/**
	 * 创建一行，并把当前行加1	
	 */
	public void createRow() {
		row = sheet.createRow(rowNum);
		rowNum++;
	}

	/**
	 * 创建一个sheet
	 * @param sheetName
	 * 			sheet名字
	 */
	public void createSheet(String sheetName) {
		sheet = wb.createSheet(sheetName);

	}

	/**
	 * 设置一个单元格内容
	 * @param data
	 * 			单元格内容
	 * @param cellNum
	 * 			单元格所属位置
	 */
	public void setCell(String data, int cellNum) {
		createCell(cellNum);
		cell.setEncoding(HSSFCell.ENCODING_UTF_16);
		cell.setCellValue(data);
	}

	/**
	 * 设置单元格内容
	 * @param datas
	 * 			单元格数据
	 * @return 当前对象
	 */
	public CreateExcelImpl setCellData(List<?> datas) throws Exception{
		List<String> list = excelInfo.getPropertys();
		
		for(int j = 0; j < datas.size(); j++){
			Object obj = datas.get(j);
			createRow();
			for(int i = 0; i < list.size(); i++){
				setCell(excelInfo.getContent(obj, list.get(i)),i);
			}
		}
		return this;
	}

	/**
	 * 设置表头内容
	 * @return 当前对象
	 */
	public CreateExcelImpl setHead() {
		List<String> datas = excelInfo.getPropertyNames();
		if(datas.size() == 0){
			datas = excelInfo.getHeaders();
		}
		createRow();
		for(int i = 0; i < datas.size(); i++){
			setCell((String)datas.get(i), i);
		}
		return this;
	}

	/**
 	 * 设置标题内容
 	 * @param title
 	 * 			标题
 	 * @return 当前对象
 	 */
	public CreateExcelImpl setTitle(String title) {
		this.createRow();
		this.createCell(0);
		
		HSSFFont titlefont = wb.createFont();
		titlefont.setFontName("Arial");
		titlefont.setBoldweight(titlefont.BOLDWEIGHT_BOLD);
		titlefont.setFontHeight((short)400);
		HSSFCellStyle titleStyle = wb.createCellStyle();
		titleStyle.setFont(titlefont);
		titleStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		cell.setCellStyle(titleStyle);
		cell.setEncoding(HSSFCell.ENCODING_UTF_16);
		
		cell.setCellValue(title);
		sheet.addMergedRegion(new Region(0, (short)0, 1, (short)(excelInfo.getNum()-1)));
		rowNum++;
		return this;
	}

	/**
	 * 获取HSSFWorkbook
	 * @return HSSFWorkbook
	 */
	public HSSFWorkbook getWb() {
		return wb;
	}

}

package lml.excel.service.impl;

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 lml.excel.annotation.PropertyAnnotation;
import lml.excel.service.ExcelInfo;

/**
 * 获取相应类实例的有效信息
 *
 */
@SuppressWarnings("unchecked")
public class ExcelInfoImpl implements ExcelInfo {

	private Class clazz = null;
	
	//有效属性个数
	private int num = 0;
	
	//有效属性数组
	private List<String> propertys = new ArrayList<String>();
	
	//有效属性信息数组
	List<String> propertyNames = new ArrayList<String>();
	
//	需导出字段
	List<String> fieldsName = new ArrayList<String>();
	
	//有效属性排序键
//	List<Integer> sortKey = new ArrayList<Integer>();
	
	/**
	 * 得到类实例
	 * @param className
	 * 			类的全路径
	 */
	public ExcelInfoImpl(String className,List<String> fieldsName){
		this.fieldsName = fieldsName;
		try{
			clazz = Class.forName(className);
		}catch(Exception e){
			e.printStackTrace();
		}
		
	}
	
	/**
	 * 获取有效属性所对应的值
	 * @param methodName
	 * 			有效属性
	 * @return String 
	 */
	@SuppressWarnings("unchecked")
	public String getContent(Object obj, String methodName) throws Exception {
		String realMethodName = "get" + methodName.substring(0,1).toUpperCase() + methodName.substring(1);
		Method method = clazz.getMethod(realMethodName, new Class[]{});
		if(null == method.invoke(obj, new Object[]{}) || "".equals(method.invoke(obj, new Object[]{}))){
			return "";
		}else{
			return method.invoke(obj, new Object[]{}).toString();
		}
	}

	/**
 	 * 获取表头数据
 	 * @return String[] 表头数据所组成的数组
 	 */
	@SuppressWarnings("unchecked")
	public List<String> getHeaders() {
		//得到类实例的所有属性
		Field[] fields = clazz.getDeclaredFields();
		//属性信息
		String propertyName = "";
		
		int PropertySortKey = 0;
		
		Map mapPropertys = new HashMap();
		
		Map mapPropertyNames = new HashMap();
		
		boolean flag = false;
		//通过循环比较得到有效属性
		
		if(0 != this.fieldsName.size()){
			for(int i = 0;i < fields.length;i++){
				if(null == fields[i].getAnnotation(PropertyAnnotation.class)){
					continue;
				}
				propertyName = fields[i].getAnnotation(PropertyAnnotation.class).PropertyName();
				for(String str : fieldsName){
					if(str.equals(propertyName)){
						propertys.add(fields[i].getName());
						propertyNames.add(propertyName);
					}
				}
			}
		}else{
			//通过循环比较得到有效属性
			for(int i = 0; i < fields.length; i++){	
				//得到相应属性的信息
					if(null == fields[i].getAnnotation(PropertyAnnotation.class)){
						continue;
					}
					
				propertyName = fields[i].getAnnotation(PropertyAnnotation.class).PropertyName();
				PropertySortKey = fields[i].getAnnotation(PropertyAnnotation.class).PropertySortKey();
				//判断是否为有效属性
				if(null != propertyName){
					if(!flag){
						if(PropertySortKey == -1){
							if("Unknown".equals(propertyName)){
								propertys.add(fields[i].getName());
								propertyNames.add(fields[i].getName());
							}else{
								propertys.add(fields[i].getName());
								propertyNames.add(propertyName);
							}
						}else{
							flag = true;
						}
					}
					if(flag){
						if("Unknown".equals(propertyName)){
							mapPropertys.put(PropertySortKey, fields[i].getName());
							mapPropertyNames.put(PropertySortKey, fields[i].getName());
						}else{
							mapPropertys.put(PropertySortKey, fields[i].getName());
							mapPropertyNames.put(PropertySortKey, propertyName);
						}
					}
					
				}
			}
			if(flag){
				sortPropertys(mapPropertys,mapPropertyNames);
			}
		}
		return propertyNames;
	}
	
	//有效属性排序

  	public void sortPropertys(Map mapPropertys, Map mapPropertyNames){
		
		for(int i = 1; i <= mapPropertys.size(); i++){
			propertys.add((String)mapPropertys.get(i));
			propertyNames.add((String)mapPropertyNames.get(i));
		}
		
	}

	/**
	 * 获取有效属性数组
	 * @return
	 */
	public List<String> getPropertys() {
		return propertys;
	}

	/**
	 * 获取有效属性信息
	 * @return
	 */
	public List<String> getPropertyNames() {
		return propertyNames;
	}

	/**
	 * 获取有效属性个数
	 * @return
	 */
	public int getNum() {
		num = getPropertys().size();
		if(num == 0){
			getHeaders();
			num = getPropertys().size();
		}
		return num;
	}
	
	
	
}

package lml.excel.service.impl;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import lml.excel.service.ExcelService;

/**
 * 创建并获取Excel的服务类
 *
 */
public class ExcelServiceImpl implements ExcelService {

	/**
	 * 创建Excel
	 * @param clazz
	 * 			类名
	 * @param datas
	 * 			数据
	 * @param title
	 * 			标题
	 * @return
	 */
	public HSSFWorkbook createExcel(String clazz, List<?> datas, String title,List<String> fieldsName) throws Exception{
		CreateExcelImpl createExcel = new CreateExcelImpl(clazz,fieldsName); 
		//创建标题、表头、以及单元格数据
		createExcel.setTitle(title).setHead().setCellData(datas);
		
		return createExcel.getWb();
	}

	/**
	 * 获取Excel
	 * @param clazz
	 * 			类名
	 * @param datas
	 * 			数据
	 * @param title
	 * 			标题
	 * @return
	 */
	public InputStream getExcelInputStream(String clazz, List<?> datas,
			String title,List<String> fieldsName) throws Exception {
		
		ByteArrayOutputStream os = new ByteArrayOutputStream();
		
		try
		{	
			createExcel(clazz, datas, title,fieldsName).write(os);
		}
		catch (IOException e)
		{
			e.printStackTrace();
		}
		
		byte[] content = os.toByteArray();
		
		InputStream is = new ByteArrayInputStream(content);
		
		return is;
	}

	
}

4、Demo Action

package lml.sf.pojo.action;

import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import lml.base.BaseDAO;
import lml.excel.service.impl.ExcelServiceImpl;
import lml.sf.pojo.V_SF_STUINFO;

import com.opensymphony.xwork2.ActionSupport;

public class STUINFOAction extends ActionSupport {
	private String filename;
	private String Tempstr;
	private List<String> fieldsName = new ArrayList<String>();
	
	private InputStream downStream;
	
	public String getFilename() {
		try {
			filename = new String(filename.getBytes(),"ISO8859-1");
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return filename + ".xls";
	}
	public void setFilename(String filename) {
		this.filename = filename;
	}
	public List<String> getFieldsName() {
		return fieldsName;
	}
	public void setFieldsName(List<String> fieldsName) {
		this.fieldsName = fieldsName;
	}
	
	public InputStream getDownStream() throws Exception{
		return downStream;
	}
	public void setDownStream(InputStream downStream) {
		this.downStream = downStream;
	}
	public String getTempstr() {
		return Tempstr;
	}
	public void setTempstr(String tempstr) {
		Tempstr = tempstr;
	}
	
	
	
	public String initExcel(){
		return SUCCESS;
	}
	
	@Override
	public String execute() throws Exception {
		return "excelinit";
	}
	
	public String doexport() throws Exception{
		if(null != Tempstr && !"".equals(Tempstr)){
			String[] strArray = Tempstr.split(",");
			for(int i=0;i<strArray.length;i++){
				if(null != strArray[i] && !"".equals(strArray[i])){
					this.fieldsName.add(strArray[i]);
				}
			}
			this.filename = "收费学生信息";
			BaseDAO DAO = new BaseDAO();
			List<V_SF_STUINFO> datas = new ArrayList<V_SF_STUINFO>();
			datas = DAO.getAll(V_SF_STUINFO.class);
			ExcelServiceImpl excel = new ExcelServiceImpl();
			this.downStream = excel.getExcelInputStream("lml.sf.pojo.V_SF_STUINFO", datas, "收费学生信息导出Excel_Demo",fieldsName);
			return SUCCESS;
		}
		return ERROR;
	}
	
	public String ioexport() throws Exception{
		this.filename = "收费学生信息";
		BaseDAO DAO = new BaseDAO();
		List<V_SF_STUINFO> datas = new ArrayList<V_SF_STUINFO>();
		datas = DAO.getAll(V_SF_STUINFO.class);
		ExcelServiceImpl excel = new ExcelServiceImpl();
		this.downStream = excel.getExcelInputStream("lml.sf.pojo.V_SF_STUINFO", datas, "收费学生信息导出Excel_Demo",new ArrayList<String>());
		return SUCCESS;
	}
	
	
}

5、struts.xml 配置

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
	<constant name="struts.custom.il8n.resources" value="message"></constant>
	<constant name="struts.i18n.encoding" value="UTF-8"></constant>
	<package name="excel" extends="struts-default">
		<action name="Export" class="lml.sf.pojo.action.STUINFOAction">
			<result name="excelinit">/STUINFO.jsp</result>
		</action>
		<action name="Ioexport" class="lml.sf.pojo.action.STUINFOAction" method="doexport">
			<result name="success" type="stream">
				<param name="contentType">application/vnd.ms-excel</param>
				<param name="contentDisposition">attachment;filename=${filename}</param>
				<param name="inputName">downStream</param>
			</result>
			<result name="error">/STUINFO.jsp</result>
		</action>
	</package>
</struts>

package lml.sf.pojo;

import lml.excel.annotation.PropertyAnnotation;

/**
 * @author 报到收费学生信息视图
 * @hibernate.class table="V_SF_STUINFO"
 */
public class V_SF_STUINFO {
	/**
	 * 学生ID
	 * 
	 * @hibernate.id generator-class="assigned"
	 */
	@PropertyAnnotation(PropertyName="学生ID",PropertySortKey=1)
	private String STUID;

	/**
	 * 学生姓名
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="学生姓名",PropertySortKey=2)
	private String XM;

	/**
	 * 学生学号
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="学生学号",PropertySortKey=3)
	private String XH;
	/**
	 * 学生性别
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="学生性别",PropertySortKey=4)
	private Integer XB;

	/**
	 * 出生年月
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="出生年月",PropertySortKey=5)
	private String CSNY;

	/**
	 * 籍贯
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="籍贯",PropertySortKey=6)
	private String JG;
	/**
	 * 民族
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="民族",PropertySortKey=7)
	private String MZ;
	/**
	 * 政治面貌
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="政治面貌",PropertySortKey=8)
	private String ZZMM;
	/**
	 * 家庭住址
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="家庭住址",PropertySortKey=9)
	private String JTZZ;
	/**
	 * 邮政编码
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="邮政编码",PropertySortKey=10)
	private String YZBM;
	/**
	 * 个人电话
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="个人电话",PropertySortKey=11)
	private String GRDH;
	/**
	 * 家庭电话
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="家庭电话",PropertySortKey=12)
	private String JTDH;

	/**
	 * 是否走读
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="是否走读",PropertySortKey=13)
	private Integer ISZD = new Integer(0);
	/**
	 * 年级代码
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="年级代码",PropertySortKey=14)
	private String NJDM;
	/**
	 * 年级名称
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="年级名称",PropertySortKey=15)
	private String NJMC;
	/**
	 * 所属班级ID
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="所属班级ID",PropertySortKey=16)
	private String BJDM;

	/**
	 * 所属班级名字
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="所属班级名称",PropertySortKey=17)
	private String BJMC;

	/**
	 * 所属专业ID
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="所属专业ID",PropertySortKey=18)
	private String ZYDM;
	/**
	 * 所属专业名字
	 * 
	 * @hibernate.property
	 */
	@PropertyAnnotation(PropertyName="所属专业名字",PropertySortKey=19)
	private String ZYMC;
	

	public V_SF_STUINFO() {
	}

	public String getSTUID() {
		return STUID;
	}

	public void setSTUID(String stuid) {
		STUID = stuid;
	}

	public String getXM() {
		return XM;
	}

	public void setXM(String xm) {
		XM = xm;
	}

	public String getXH() {
		return XH;
	}

	public void setXH(String xh) {
		XH = xh;
	}

	public String getCSNY() {
		return CSNY;
	}

	public void setCSNY(String csny) {
		CSNY = csny;
	}

	public String getJG() {
		return JG;
	}

	public void setJG(String jg) {
		JG = jg;
	}

	public String getMZ() {
		return MZ;
	}

	public void setMZ(String mz) {
		MZ = mz;
	}

	public String getGRDH() {
		return GRDH;
	}

	public void setGRDH(String grdh) {
		GRDH = grdh;
	}

	public String getJTDH() {
		return JTDH;
	}

	public void setJTDH(String jtdh) {
		JTDH = jtdh;
	}

	public Integer getISZD() {
		if (ISZD == null) {
			return 0;
		} else {
			return ISZD;
		}
	}

	public void setISZD(Integer iszd) {
		ISZD = iszd;
	}

	public String getNJDM() {
		return NJDM;
	}

	public void setNJDM(String njdm) {
		NJDM = njdm;
	}

	public String getNJMC() {
		return NJMC;
	}

	public void setNJMC(String njmc) {
		NJMC = njmc;
	}

	public String getBJDM() {
		return BJDM;
	}

	public void setBJDM(String bjdm) {
		BJDM = bjdm;
	}

	public String getBJMC() {
		return BJMC;
	}

	public void setBJMC(String bjmc) {
		BJMC = bjmc;
	}

	public String getZYDM() {
		return ZYDM;
	}

	public void setZYDM(String zydm) {
		ZYDM = zydm;
	}

	public String getZYMC() {
		return ZYMC;
	}

	public void setZYMC(String zymc) {
		ZYMC = zymc;
	}

	public String getZZMM() {
		return ZZMM;
	}

	public void setZZMM(String zzmm) {
		ZZMM = zzmm;
	}

	public String getJTZZ() {
		return JTZZ;
	}

	public void setJTZZ(String jtzz) {
		JTZZ = jtzz;
	}

	public String getYZBM() {
		return YZBM;
	}

	public void setYZBM(String yzbm) {
		YZBM = yzbm;
	}

	public Integer getXB() {
		return XB;
	}

	public void setXB(Integer xb) {
		XB = xb;
	}

}