从test.jsp到test_jsp.java(文件分析)

最新推荐文章于 2022-11-13 14:34:53 发布

原创最新推荐文章于 2022-11-13 14:34:53 发布 · 1.7k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#null #import #jsp #integer #application #vector

J2SE 专栏收录该内容

34 篇文章

订阅专栏

本文介绍了一个具体的JSP页面实现方式，该页面通过继承HttpJspBase类并实现JspSourceDependent接口，处理请求和响应。文章展示了如何使用静态初始化块来管理依赖项，并详细解释了_jspService方法的工作原理。

test_jsp.java中源码：
这个类是final类继承了org.apache.jasper.runtime.HttpJspBase类，实现了org.apache.jasper.runtime.JspSourceDependent接口
public final class test_jsp extends org.apache.jasper.runtime.HttpJspBase
    implements org.apache.jasper.runtime.JspSourceDependent

如果在jsp中有"include"语句，则会在java中用静态初始化块来创建Vector，并添加数据。
例如：
private static java.util.Vector _jspx_dependants;

static {
    _jspx_dependants = new java.util.Vector(1);
    _jspx_dependants.add("/test/../../common/commheader.jsp");
}

public java.util.List getDependants() {
    return _jspx_dependants;
}

方法_jspService用来处理request及给出回应response
public void _jspService(HttpServletRequest request, HttpServletResponse response)
        throws java.io.IOException, ServletException

import javax.servlet.*;

import javax.servlet.http.*;

import javax.servlet.jsp.*;

import com.midi.VendorActionEntrance;

import com.midi.IVendorConstants;

public final class test_jsp extends org.apache.jasper.runtime.HttpJspBase

implements org.apache.jasper.runtime.JspSourceDependent {

private static java.util.Vector _jspx_dependants;

static {

_jspx_dependants = new java.util.Vector(1);

_jspx_dependants.add("/caraudit/jsp/biz/warehouse/../../common/commheader.jsp");

}

public java.util.List getDependants() {

return _jspx_dependants;

}

public void _jspService(HttpServletRequest request, HttpServletResponse response)

throws java.io.IOException, ServletException {

JspFactory _jspxFactory = null;

PageContext pageContext = null;

HttpSession session = null;

ServletContext application = null;

ServletConfig config = null;

JspWriter out = null;

Object page = this;

JspWriter _jspx_out = null;

try {

_jspxFactory = JspFactory.getDefaultFactory();

response.setContentType("text/html;charset=gb2312");

pageContext = _jspxFactory.getPageContext(this, request, response,

null, true, 8192, true);

application = pageContext.getServletContext();

config = pageContext.getServletConfig();

session = pageContext.getSession();

out = pageContext.getOut();

_jspx_out = out;

out.write(" ");

response.setHeader("Cache-Control","no-store"); //HTTP 1.1

response.setHeader("Pragma","no-cache"); //HTTP 1.0

response.setDateHeader ("Expires", 0); //prevents caching at the proxy server

out.write(" ");

out.write(' ');

String strUrl = (String) request.getParameter("srcUrl");

VendorActionEntrance vae = new VendorActionEntrance();

vae.doPost(request, response);

Integer iAf = (Integer) request.getAttribute(IVendorConstants.AFFECTEDROW);

if (iAf.intValue() == -1) {

response.sendRedirect("../../common/error.jsp");

return;

}

out.write(" <html> <head> <title>test.jsp</title> </head> <body>test </body> </html> ");

} catch (Throwable t) {

if (!(t instanceof SkipPageException)){

out = _jspx_out;

if (out != null && out.getBufferSize() != 0)

out.clearBuffer();

if (pageContext != null) pageContext.handlePageException(t);

}

} finally {

if (_jspxFactory != null) _jspxFactory.releasePageContext(pageContext);

}