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标题: Jsp 实例应用-用jsp动态输出excel文档和中文乱码问题的解决 [打印本页]

作者: awagink    时间: 2008-3-25 22:28
标题: Jsp 实例应用-用jsp动态输出excel文档和中文乱码问题的解决
  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 c %>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。




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