java 导出excel到客户端（本地）例子 用poi和servlet实现的

http://m.blog.csdn.net/article/details?id=49635837

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <display-name></display-name>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>ExcelExportServlet</servlet-name>
<servlet-class>com.lujinyong.servlet.ExcelExportServlet</servlet-class>
</servlet>
<servlet-name>ExcelExportServlet</servlet-name>
<url-pattern>[color=red]/servlet/ExcelExportServlet[/color]</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>

java
package com.lujinyong.servlet;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
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.HSSFFont;
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;

public class ExcelExportServlet extends HttpServlet {
//访问网址：http://localhost:8080/excelExport/servlet/ExcelExportServlet
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("octets/stream");
// response.addHeader("Content-Disposition", "attachment;filename=test.xls");
String excelName = "学生信息表";
//转码防止乱码
response.addHeader("Content-Disposition", "attachment;filename="+new String( excelName.getBytes("gb2312"), "ISO8859-1" )+".xls");
String[] headers = new String[]{"编号","姓名","年龄","性别"};
try {
OutputStream out = response.getOutputStream();
exportExcel(excelName,headers, getList(), out,"yyyy-MM-dd");
out.close();
System.out.println("excel导出成功！");
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
/**
*
* @Description: 模拟从数据库中查询出来的数据，一般是数据表中的几列
* @Auther: lujinyong
* @Date: 2013-8-22 下午2:53:58
*/
public List<Map<String,Object>> getList(){
List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
for(int i = 0; i<100;i++){
Map<String,Object> map = new HashMap<String, Object>();
map.put("number",1000+i);
map.put("name", "张三"+i);
int age = (int)(Math.random()*100);
do{
age = (int)(Math.random()*100);
}while(age<10||age>15);
map.put("age", age);
map.put("sex", age%2==0?0:1);//获得随机性别
list.add(map);
}
return list;
}
/**
*
* @Description: 生成excel并导出到客户端（本地）
* @Auther: lujinyong
* @Date: 2013-8-22 下午3:05:49
*/
protected void exportExcel(String title,String[] headers,List mapList,OutputStream out,String pattern){
//声明一个工作簿
HSSFWorkbook workbook = new HSSFWorkbook();
//生成一个表格
HSSFSheet sheet = workbook.createSheet(title);
//设置表格默认列宽度为15个字符
sheet.setDefaultColumnWidth(20);
//生成一个样式，用来设置标题样式
HSSFCellStyle style = workbook.createCellStyle();
//设置这些样式
style.setFillForegroundColor(HSSFColor.SKY_BLUE.index);
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);
//生成一个字体
HSSFFont font = workbook.createFont();
font.setColor(HSSFColor.VIOLET.index);
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
//把字体应用到当前的样式
style.setFont(font);
// 生成并设置另一个样式,用于设置内容样式
HSSFCellStyle style2 = workbook.createCellStyle();
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);
// 生成另一个字体
HSSFFont font2 = workbook.createFont();
font2.setBoldweight(HSSFFont.BOLDWEIGHT_NORMAL);
// 把字体应用到当前的样式
style2.setFont(font2);
//产生表格标题行
HSSFRow row = sheet.createRow(0);
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);
}
for (int i=0;i<mapList.size();i++) {
Map<String,Object> map = (Map<String, Object>) mapList.get(i);
row = sheet.createRow(i+1);
int j = 0;
Object value = null;
value=map.get("number");
if(value instanceof Integer){
row.createCell(j++).setCellValue(String.valueOf(value));
}
row.createCell(j++).setCellValue(map.get("name").toString());
value=map.get("age");
if(value instanceof Integer){
row.createCell(j++).setCellValue(String.valueOf(value));
}
row.createCell(j++).setCellValue("0".equals(map.get("sex").toString())?"女":"男");
}
try {
workbook.write(out);
} catch (IOException e) {
e.printStackTrace();
}
}

}