JSP动态输出Excel及中文乱码的解决

JSP编程 2016-11-10

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!

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