JSP動態輸出Excel及中文亂碼的解決

來源:互聯網
上載者:User

  最近在網上看到一個用java來操縱excel的open source,在weblogic上試用了一下,覺得很不錯,特此向大家推薦一下。

  首先去http://www.andykhan.com/jexcelapi/index.html下載最新的JExcelApi,把jxl.jar置於你的classpath中。

  寫一個javaBean,利用JExcelApi來動態產生excel文檔,我這裡寫一個最簡單的,示意性的。複雜的你可能還要查詢資料庫什麼的。

///////////////////////////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, "我愛中國");
  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, "中國愛我",wcfFC);
  ws.addCell(labelC);
  //寫入Exel工作表
  wwb.write();
  //關閉Excel工作薄對象
  wwb.close();
 }

 //最好寫一個這樣的main方法來測試一下你的這個class是否寫好了。
 public static void main(String[] args)throws Exception{
  File f=new File("kk.xls");
  f.createNewFile();
  writeExcel(new FileOutputStream(f));
 }
}

  寫一個jsp,來利用Test這個javabean輸出excel文檔。

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

<%@page import="com.jagie.test.Test" %>
<%
 response.reset();
 response.setContentType("application/vnd.ms-excel");
 Test.writeExcel(response.getOutputStream());
%>

  這樣就大功告成了,你用ie訪問test_excel.jsp就能在ie裡面開啟動態產生的excel文檔了。一點亂碼也沒有。

  也許有人會問:response.reset();可不可以不要這一句,我的建議是一定要寫,除非你能保證response的buffer裡面沒有別的東西。

  還有人也許會問:我在jsp開頭加上<%@page contentType="application/vnd.ms-excel;charset=GBK" %>這一句,去掉response.setContentType("application/vnd.ms-excel");行不行?回答這個問題很簡單,就是查看jsp伺服器編譯jsp後產生的java代碼,如果改成這樣,我的welogic7編譯test_excel.jsp後產生的java檔案的示意性代碼是這樣的:

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...
}

  很明顯,屏蔽response.setContentType("application/vnd.ms-excel");後,在Test.writeExcel(response.getOutputStream());之前,response.reset(); 之後沒有設定response contenttype的正確類型,當然輸出為亂碼了。而正確輸出excel的jsp的編譯後源碼是這樣的:

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();之後,Test.writeExcel(response.getOutputStream());之前正確的設定了response的輸出內容。所以輸出就正常了。

  最後,希望這篇文章能對你有所啟發,如有錯誤之處,敬請批評指正!

相關文章

聯繫我們

該頁面正文內容均來源於網絡整理,並不代表阿里雲官方的觀點,該頁面所提到的產品和服務也與阿里云無關,如果該頁面內容對您造成了困擾,歡迎寫郵件給我們,收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容,歡迎發送郵件至: info-contact@alibabacloud.com 進行舉報並提供相關證據,工作人員會在 5 個工作天內聯絡您,一經查實,本站將立刻刪除涉嫌侵權內容。

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.