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里面打開動態生成的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里面沒有別的東西。

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服務器編譯jsp后生成的java代碼，如果改成這樣，我的welogic7編譯test_excel.jsp后生成的java文件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");后，在Test.writeExcel(response.getOutputStream());之前，response.reset(); 之后沒有設置response contenttype的正確類型，當然輸出為亂碼了。而正確輸出excel的jsp的編譯后源碼是這樣的:

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