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();              }          }                }