struts jxl导出Excel

struts2配置文件

<?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>
        <package name="vclassenroll" extends="json-default" namespace="/vclassenroll">
            <action name="op/*" class="com.xxx.action.VclassEnrollOperateAction" method="{1}">
                <result name="excel" type="stream">  
                <param name="contentType">  
                    application/vnd.ms-excel  
                </param>  
                <param name="inputName">excelStream</param>  
                <param name="contentDisposition">  
                   filename="${fileName}.xls"
                </param>  
                <param name="bufferSize">1024</param>  
            </result>
            </action>
        </package>
</struts>

struts2对应的action

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Random;
import javax.annotation.Resource;

public class VclassEnrollOperateAction extends BaseAction {
    private static final long serialVersionUID = -941593970307742358L;
    @Resource
    private VclassEnrollService vclassEnrollService;
    private VclassEnroll vclassEnroll;
    private String classId;
    private InputStream excelStream;
    private String fileName;

    public String exportExcel() {
        if(vclassEnroll == null){
            vclassEnroll = new VclassEnroll();
        }
        if(StringUtils.isNotNull(classId)){
            vclassEnroll.setVclass_id(Integer.parseInt(classId));
            List<VclassEnroll> list = vclassEnrollService.getList(vclassEnroll);
            // 将OutputStream转化为InputStream
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            List<String> columns = new ArrayList<String>();
            columns.add("序号");
            columns.add("姓名");
            columns.add("年级");
            columns.add("班级");
            columns.add("电话");
            String cname ="";
            if(list != null && list.size() > 0){
                cname = list.get(0).getCname();
            }

            JxlExcelUtils.getExcelStream(out, list, "报名记录-"+cname, columns);
            excelStream =  new ByteArrayInputStream(out.toByteArray());
            fileName = createFileName();
        }
        return "excel";

    }



     /** 
     * 以年月日时分秒毫秒+4位随机数的格式来创建一个文件名，不带扩展名 
     * @return 文件名 
     */  
    public static String createFileName() {  
        StringBuffer sb = new StringBuffer();  
        Date date = new Date();  
        //获取年月日时分秒  
        sb.append(new SimpleDateFormat("yyyyMMddHHmmss").format(date));  
        //毫秒  
        String milli = String.valueOf(date.getTime() % 1000);  
        while (milli.length() < 3) {  
            milli = "0" + milli;  
        }  
        sb.append(milli);  
        //四位随机数  
        String rondom = String.valueOf(new Random().nextInt(10000));  
        while (rondom.length() < 4) {  
            rondom = "0" + rondom;  
        }  
        sb.append(rondom);  
        return sb.toString();  
    }  

}

工具类

import java.io.ByteArrayOutputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpServletResponse;
import jxl.SheetSettings;
import jxl.Workbook;
import jxl.format.Alignment;
import jxl.format.Colour;
import jxl.format.VerticalAlignment;
import jxl.write.Label;
import jxl.write.WritableCellFormat;
import jxl.write.WritableFont;
import jxl.write.WritableSheet;
import jxl.write.WritableWorkbook;
public class JxlExcelUtils {

    /** 
     * @author  
     * @param objData 导出内容数组 
     * @param sheetName 导出工作表的名称 
     * @param columns 导出Excel的表头数组 
     * @return 
     */  
    public static int getExcelStream(ByteArrayOutputStream os, List<VclassEnroll> list, String sheetName,List<String> columns) {  
        int flag = 0;  
        //声明工作簿jxl.write.WritableWorkbook  
        WritableWorkbook workbook;  
        try {  
            //根据传进来的file对象创建可写入的Excel工作薄  

            workbook = Workbook.createWorkbook(os);  

            /* 
             * 创建一个工作表、sheetName为工作表的名称、"0"为第一个工作表 
             * 打开Excel的时候会看到左下角默认有3个sheet、"sheet1、sheet2、sheet3"这样 
             * 代码中的"0"就是sheet1、其它的一一对应。 
             * createSheet(sheetName, 0)一个是工作表的名称，另一个是工作表在工作薄中的位置 
             */  
            WritableSheet ws = workbook.createSheet(sheetName, 0);  

            SheetSettings ss = ws.getSettings();  
            ss.setVerticalFreeze(1);//冻结表头  

            WritableFont font1 =new WritableFont(WritableFont.createFont("微软雅黑"), 10 ,WritableFont.BOLD);  
            WritableFont font2 =new WritableFont(WritableFont.createFont("微软雅黑"), 9 ,WritableFont.NO_BOLD);  
            WritableCellFormat wcf = new WritableCellFormat(font1);  
            WritableCellFormat wcf2 = new WritableCellFormat(font2);  
            WritableCellFormat wcf3 = new WritableCellFormat(font2);//设置样式，字体  

            //创建单元格样式  
            //WritableCellFormat wcf = new WritableCellFormat();  

            //背景颜色  
            wcf.setBackground(jxl.format.Colour.YELLOW);  
            wcf.setAlignment(Alignment.CENTRE);  //平行居中  
            wcf.setVerticalAlignment(VerticalAlignment.CENTRE);  //垂直居中  
            wcf3.setAlignment(Alignment.CENTRE);  //平行居中  
            wcf3.setVerticalAlignment(VerticalAlignment.CENTRE);  //垂直居中  
            wcf3.setBackground(Colour.LIGHT_ORANGE);  
            wcf2.setAlignment(Alignment.CENTRE);  //平行居中  
            wcf2.setVerticalAlignment(VerticalAlignment.CENTRE);  //垂直居中  

            /* 
             * 这个是单元格内容居中显示 
             * 还有很多很多样式 
             */  
            wcf.setAlignment(Alignment.CENTRE);  

            //判断一下表头数组是否有数据  
            if (columns != null && columns.size() > 0) {  

                //循环写入表头  
                for (int i = 0; i < columns.size(); i++) {  

                    /* 
                     * 添加单元格(Cell)内容addCell() 
                     * 添加Label对象Label() 
                     * 数据的类型有很多种、在这里你需要什么类型就导入什么类型 
                     * 如：jxl.write.DateTime 、jxl.write.Number、jxl.write.Label 
                     * Label(i, 0, columns[i], wcf) 
                     * 其中i为列、0为行、columns[i]为数据、wcf为样式 
                     * 合起来就是说将columns[i]添加到第一行(行、列下标都是从0开始)第i列、样式为什么"色"内容居中 
                     */  
                    ws.addCell(new Label(i, 0, columns.get(i), wcf));  
                }  

                //判断表中是否有数据  
                if (list != null && list.size() > 0) {  
                    //循环写入表中数据  
                    for (int i = 0; i < list.size(); i++) { 
                        int j = i+1;
                        ws.addCell(new Label(0, j, i+""));
                        ws.addCell(new Label(1, j, list.get(i).getStu_name()));
                        ws.addCell(new Label(2, j, list.get(i).getGradeid()+""));
                        ws.addCell(new Label(3, j, list.get(i).getClassid()+""));
                        ws.addCell(new Label(4, j, list.get(i).getTelephone()+""));
                    }  
                }else{  
                    flag = -1;  
                }  

                //写入Exel工作表  
                workbook.write();  

                //关闭Excel工作薄对象   
                workbook.close();  

                //关闭流  
                os.flush();  
                os.close();  

                os =null;  
            }  
        }catch (IllegalStateException e) {  
            System.err.println(e.getMessage());  
        }  
        catch (Exception ex) {  
            flag = 0;  
            ex.printStackTrace();  
        }  

        return flag;  
    }  

}