越王勾践的故事200字:关于servlet,以下这段是什么意思?

来源:百度文库 编辑:神马品牌网 时间:2024/05/06 07:12:24
package aaa;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestServlet extends HttpServlet
{
public void service(HttpServletRequest req, HttpServletResponse res)
{
try
{
String fowd = "";

//get the from's data
String parm1 = req.getParameter("name_param1");
String parm2 = req.getParameter("name_param2");

//do some thing

//forword eg
if (fowd.equals("success"))
{
this.forward("/success.jsp",req, res);
}
else if (fowd.equals("failed"))
{
this.forward("/failed.jsp",req, res);
}
else
{
this.forward("/default.jsp",req, res);
}
}
catch(Exception e)
{
//do exception
}
}

protected void forward(String page, HttpServletRequest req, HttpServletResponse res)
{
try
{
RequestDispatcher dispatcher = null;
ServletContext context = getServletContext();
dispatcher = context.getRequestDispatcher(page);
dispatcher.forward(req, res);
}
catch(Exception e)
{

}
}
}
try
{
string fowd = "";
从这里开始是什么意思?
能不能说的详细点?

根据获取的
name_param1
name_param2
分别处理不同操作转向到
success
failed
成功=default.jsp
以及版权保护页

(非专业回答)

哪里不明白?

try
{
String fowd = "";

//get the from's data
String parm1 = req.getParameter("name_param1"); //从request中提取名为"name_param1"的变量的值,赋给param1
String parm2 = req.getParameter("name_param2"); //从request中提取名为"name_param2"的变量的值,赋给param2

//do some thing //这里做的事,可能改变了fowd的值

//forword eg
if (fowd.equals("success")) //如果fowd的值为"success"
{
this.forward("/success.jsp",req, res); //跳转到页面success.jsp(这里调用了下面的foward方法)
}
else if (fowd.equals("failed")) //如果fowd的值为"failed"
{
this.forward("/failed.jsp",req, res); //跳转到页面failed.jsp
}
else ////如果fowd的值不是"success"也不是"failed"
{
this.forward("/default.jsp",req, res); //跳转到页面default.jsp
}
}
catch(Exception e) //处理异常
{
//do exception
}
}

protected void forward(String page, HttpServletRequest req, HttpServletResponse res)
//这是前面页面跳转调用的方法,protected不是什么版权保护,指的是访问级别控制,指这个类的子类可以访问这个方法,甚至这个子类在包外都可以访问。这个就不多讲了。public default protected private这四个访问级别控制搞不清楚,那么你先搞清楚那四个,问现在这个问题就没意义了。
{
try
{
RequestDispatcher dispatcher = null; //创建一个RequestDispatcher实例
ServletContext context = getServletContext(); //创建一个ServletContext实例
dispatcher = context.getRequestDispatcher(page); //给RequestDispatcher实例赋值,用于跳转
dispatcher.forward(req, res); //这里执行了页面跳转
}
catch(Exception e) //处理异常
{

}