JSP动态输出Excel及中文乱码的解决

  最近在网上看到一个用java来操纵excel的open source,在weblogic上试用了一下,觉得很不错,特此向大家推荐一下。

  首先去http://www.andykhan.com/jexcelapi/index.html下载最新的JExcelApi,把jxl.jar置于你的classpath中。

  写一个javaBean,利用JExcelApi来动态生成excel文档,我这里写一个最简单的,示意性的。复杂的你可能还要查询数据库什么的。

  ///////////////////////////Test.java///////////////////////////////////////////

  package com.jagie.test;

  import java.io.*;

  import jxl.*;

  import jxl.write.*;

  import jxl.format.*;

  import java.util.*;

  import java.awt.Color;

  public class Test{

   public static void writeExcel(OutputStream os) throws Exception {

  jxl.write.WritableWorkbook wwb = Workbook.createWorkbook(os);

  jxl.write.WritableSheet ws = wwb.createSheet("TestSheet1", 0);

  jxl.write.Label labelC = new jxl.write.Label(0, 0, "我爱中国");

  ws.addCell(labelC);

  jxl.write.WritableFont wfc = new jxl.write.WritableFont(WritableFont.ARIAL,20, WritableFont.BOLD, false,

  UnderlineStyle.NO_UNDERLINE, jxl.format.Colour.GREEN);

  jxl.write.WritableCellFormat wcfFC = new jxl.write.WritableCellFormat(wfc);

  wcfFC.setBackground(jxl.format.Colour.RED);

  labelC = new jxl.write.Label(6, 0, "中国爱我",wcfFC);

  ws.addCell(labelC);

  //写入Exel工作表

  wwb.write();

  //关闭Excel工作薄对象

  wwb.close();

   }

   //最好写一个这样的main方法来测试一下你的这个class是否写好了。

   public static void main(String[] args)throws Exception{

  File f=new File("kk.xls");

  f.createNewFile();

  writeExcel(new FileOutputStream(f));

   }

  }

  写一个jsp,来利用Test这个javabean输出excel文档。

  ///////////////////////////test_excel.jsp//////////////////////////

  <%@page import="com.jagie.test.Test" %>

  <%

   response.reset();

   response.setContentType("application/vnd.ms-excel");

   Test.writeExcel(response.getOutputStream());

  %>

  这样就大功告成了,你用ie访问test_excel.jsp就能在ie里面打开动态生成的excel文档了。一点乱码也没有。

  也许有人会问:response.reset();可不可以不要这一句,我的建议是一定要写,除非你能保证response的buffer里面没有别的东西。

  还有人也许会问:我在jsp开头加上<%@page contentType="application/vnd.ms-excel;charset=GBK" %>这一句,去掉response.setContentType("application/vnd.ms-excel");行不行?回答这个问题很简单,就是查看jsp服务器编译jsp后生成的java代码,如果改成这样,我的welogic7编译test_excel.jsp后生成的java文件的示意性代码是这样的:

  public void _jspService(javax.servlet.http.HttpServletRequest request,

  javax.servlet.http.HttpServletResponse response) throws java.io.IOException,

  javax.servlet.ServletException {

   // declare and set well-known variables:

   javax.servlet.ServletConfig config = getServletConfig();

   javax.servlet.ServletContext application = config.getServletContext();

   javax.servlet.jsp.tagext.Tag _activeTag = null;

   // variables for Tag extension protocol

   Object page = this;

   javax.servlet.jsp.JspWriter out;

   javax.servlet.jsp.PageContext pageContext =

   javax.servlet.jsp.JspFactory.getDefaultFactory().getPageContext(this,

   request, response, null, true, 8192, true);

   response.setHeader("Content-Type", "application/vnd.ms-excel; charset=GBK");

   out = pageContext.getOut();

   JspWriter _originalOut = out;

   javax.servlet.http.HttpSession session = request.getSession(true);

   try { // error page try block

  response.setContentType("application/vnd.ms-excel;charset=GBK");

  out.print("\r\n\r\n\r\n\r\n");

  out.print("\r\n");

  //[ /test_excel.jsp; Line: 6]

  response.reset(); //[ /test_excel.jsp; Line: 7]

  //response.setContentType("application/vnd.ms-excel");

  //[ /test_excel.jsp; Line: 8]

  Test.writeExcel(response.getOutputStream()); //[ /test_excel.jsp; Line: 9]

  } catch (Throwable __ee) {

   while (out != null && out != _originalOut) out = pageContext.popBody();

  ((weblogic.servlet.jsp.PageContextImpl)pageContext).handlePageException((Throwable)__ee);

   }

   //before final close brace...

  }

  很明显,屏蔽response.setContentType("application/vnd.ms-excel");后,在Test.writeExcel(response.getOutputStream());之前,response.reset(); 之后没有设置response contenttype的正确类型,当然输出为乱码了。而正确输出excel的jsp的编译后源码是这样的:

  public void _jspService(javax.servlet.http.HttpServletRequest request,

  javax.servlet.http.HttpServletResponse response) throws java.io.IOException,

  javax.servlet.ServletException

  {

   // declare and set well-known variables:

   javax.servlet.ServletConfig config = getServletConfig();

   javax.servlet.ServletContext application = config.getServletContext();

   javax.servlet.jsp.tagext.Tag _activeTag = null;

   // variables for Tag extension protocol

   Object page = this;

   javax.servlet.jsp.JspWriter out;

   javax.servlet.jsp.PageContext pageContext =

  javax.servlet.jsp.JspFactory.getDefaultFactory().getPageContext(this, request, response, null, true, 8192, true);

   out = pageContext.getOut();

   JspWriter _originalOut = out;

   javax.servlet.http.HttpSession session = request.getSession(true);

   try { // error page try block

  out.print("\r\n");

  //[ /test_excel.jsp; Line: 2]

  response.reset(); //[ /test_excel.jsp; Line: 3]

  response.setContentType("application/vnd.ms-excel"); //[ /test_excel.jsp; Line: 4]

  Test.writeExcel(response.getOutputStream()); //[ /test_excel.jsp; Line: 5]

   } catch (Throwable __ee) {

  while (out != null && out != _originalOut) out = pageContext.popBody();

  ((weblogic.servlet.jsp.PageContextImpl)pageContext).handlePageException((Throwable)__ee);

   }

    //before final close brace...

  }

  大家可以看到在response.reset();之后,Test.writeExcel(response.getOutputStream());之前正确的设置了response的输出内容。所以输出就正常了。

  最后,希望这篇文章能对你有所启发,如有错误之处,敬请批评指正!