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!
