ExportExcel

package com.yulong.ecms.common;

import java.io.IOException;
import java.io.OutputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFClientAnchor;
import org.apache.poi.hssf.usermodel.HSSFComment;
import org.apache.poi.hssf.usermodel.HSSFFont;
import org.apache.poi.hssf.usermodel.HSSFPatriarch;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
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.HSSFColor;
import org.apache.struts2.ServletActionContext;

/**
* 利用开源组件POI3.0.2动态导出EXCEL
* @author zhangfuwei
* @version v1.0
* @param <T>
* 应用泛型，代表任意一个符合javabean风格的类
* 注意这里为了简单起见，boolean型的属性xxx的get器方式为getXxx(),而不是isXxx()
* byte[]表jpg格式的图片数据
*/
public class ExportExcel<T> {

/**
* 这是一个通用的方法，利用了JAVA的反射机制，可以将放置在JAVA集合中并且符号一定条件的数据以EXCEL 的形式输出到指定IO设备上
* @param title
*  表格标题名
* @param headers
*  表格属性列名数组
* @param fields
* 要输出对象列对应的字段         
* @param dataset
*  需要显示的数据集合,集合中一定要放置符合javabean风格的类的对象。此方法支持的
* javabean属性的数据类型有基本数据类型及String,Date,byte[](图片数据)
* @param pattern
* 如果有时间数据，设定输出格式。默认为"yyy-MM-dd"
* @throws IOException
*/
@SuppressWarnings("unchecked")
public void exportExcel(String title, String[] headers, String[] fields,
Collection<T> dataset, String pattern) throws IOException {

HttpServletResponse response = ServletActionContext.getResponse();
OutputStream out = response.getOutputStream();
SimpleDateFormat sf = new SimpleDateFormat("yyy-MM-dd-HHmmss");
String filename = title + "(" + sf.format(new Date()) + ")" + ".xls";
response.setHeader("Content-Disposition", "attachment; filename="+ new String(filename.getBytes("GBK"), "ISO8859-1"));
response.setHeader("Connection", "close");
response.setHeader("Content-Type", "application/octet-stream");

HSSFWorkbook workbook = new HSSFWorkbook();// 声明一个工作薄
HSSFSheet sheet = workbook.createSheet(title);// 生成一个表格
sheet.setDefaultColumnWidth(15);// 设置表格默认列宽度为15个字节

HSSFCellStyle style = workbook.createCellStyle();// 生成一个样式
style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);// 设置这些样式
style.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);

HSSFFont font = workbook.createFont(); // 生成一个字体
font.setColor(HSSFColor.VIOLET.index);
font.setFontHeightInPoints((short) 12);
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);

style.setFont(font);// 把字体应用到当前的样式

HSSFCellStyle style2 = workbook.createCellStyle(); // 生成并设置另一个样式
style2.setFillForegroundColor(HSSFColor.LIGHT_YELLOW.index);
style2.setFillPattern(HSSFCellStyle.SOLID_FOREGROUND);
style2.setBorderBottom(HSSFCellStyle.BORDER_THIN);
style2.setBorderLeft(HSSFCellStyle.BORDER_THIN);
style2.setBorderRight(HSSFCellStyle.BORDER_THIN);
style2.setBorderTop(HSSFCellStyle.BORDER_THIN);
style2.setAlignment(HSSFCellStyle.ALIGN_CENTER);
style2.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

HSSFFont font2 = workbook.createFont();// 生成另一个字体
font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);

style2.setFont(font2);// 把字体应用到当前的样式

HSSFPatriarch patriarch = sheet.createDrawingPatriarch();// 声明一个画图的顶级管理器
HSSFComment comment = patriarch.createComment(new HSSFClientAnchor(0,0, 0, 0, (short) 4, 2, (short) 6, 5));// 定义注释的大小和位置,详见文档

comment.setString(new HSSFRichTextString("可以在POI中添加注释！"));// 设置注释内容
comment.setAuthor("fonder");// 设置注释作者，当鼠标移动到单元格上是可以在状态栏中看到该内容.

HSSFRow row = sheet.createRow(0);// 产生表格标题行
for (int i = 0; i < headers.length; i++) {
HSSFCell cell = row.createCell(i);
cell.setCellStyle(style);
HSSFRichTextString text = new HSSFRichTextString(headers[i]);
cell.setCellValue(text);
}

Iterator<T> it = dataset.iterator();// 遍历集合数据，产生数据行
int index = 0;
while (it.hasNext()) {
index++;
row = sheet.createRow(index);
T t = (T) it.next();

for (int i = 0; i < fields.length; i++) {// 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值
HSSFCell cell = row.createCell(i);
cell.setCellStyle(style2);
String fieldName = fields[i];
String getMethodName = "get"+ fieldName.substring(0, 1).toUpperCase()+ fieldName.substring(1);
try {
Class tCls = t.getClass();
Method getMethod = tCls.getMethod(getMethodName,new Class[] {});
Object value = getMethod.invoke(t, new Object[] {});

String textValue = null;// 判断值的类型后进行强制类型转换
if (value instanceof Boolean) {
textValue = String.valueOf(value);
} else if (value instanceof Date) {
if(null==pattern||"".equals(pattern)) pattern="yyyy-MM-dd";
SimpleDateFormat sdf = new SimpleDateFormat(pattern);
textValue = sdf.format(value);
} else if (value instanceof byte[]) {
row.setHeightInPoints(60);// 有图片时，设置行高为60px;
sheet.setColumnWidth(i, (short) (35.7 * 80));// 设置图片所在列宽度为80px,注意这里单位的一个换算
byte[] bsValue = (byte[]) value;
HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0,1023, 255, (short) 6, index, (short) 6, index);
anchor.setAnchorType(2);
patriarch.createPicture(anchor, workbook.addPicture(bsValue, HSSFWorkbook.PICTURE_TYPE_JPEG));
} else {// 其它数据类型都当作字符串简单处理
if (null != value) {
textValue = value.toString();
} else {
textValue = "";
}
}
cell.setCellValue(textValue);//赋值
} catch (SecurityException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
} catch(Exception e){
e.printStackTrace();
} finally {
}
}

}
//输出
workbook.write(out);
out.flush();
out.close();
}

}