HTTP Status 404

Question

在地址栏里输入localhost:8080/helloapp能出登录框但是点击之后出现HTTP Status 404 - /helloapp/dispatcher

Answer 1

package mypack;import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import java.io.*;
import java.util.*;@SuppressWarnings("serial")
public class DispatcherServlet extends GenericServlet{
           private String target="/hello.jsp";
@Override
public void service(ServletRequest request, ServletResponse response)
throws ServletException, IOException {
String username=request.getParameter("username");
String password=request.getParameter("password");
request.setAttribute("USER", username);
request.setAttribute("PASSWORD", password);
ServletContext context=getServletContext();
RequestDispatcher dispatcher=context.getRequestDispatcher(target);
dispatcher.forward(request, response);
}}

Answer 2

package mypack;import javax.servlet.*;
import javax.servlet.http.HttpServlet;
import java.io.*;
import java.util.*;@SuppressWarnings("serial")
public class DispatcherServlet extends GenericServlet{
           private String target="/hello.jsp";
@Override
public void service(ServletRequest request, ServletResponse response)
throws ServletException, IOException {
String username=request.getParameter("username");
String password=request.getParameter("password");
request.setAttribute("USER", username);
request.setAttribute("PASSWORD", password);
ServletContext context=getServletContext();
RequestDispatcher dispatcher=context.getRequestDispatcher(target);
dispatcher.forward(request, response);
}}

Answer 3

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <servlet>
     <servlet-name>dispatcher</servlet-name>
     <servlet-class>dispatcher</servlet-class>
 </servlet>
 
 <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/mypack/dispatcher</url-pattern>
 </servlet-mapping>
  <welcome-file-list>
    <welcome-file>login.html</welcome-file>
  </welcome-file-list>
</web-app>

Answer 4

<url-pattern>/mypack/dispatcher</url-pattern>
改成
/mypack/dispatcher

Answer 5

是把你的action=后面那个改成上面的那个试下

Answer 6

The requested resource (/mypack/dispatcher) is not available.
还是不行 我的环境变量是不是配错了？ 现在用的代码是从网上下的书上的源码
 CATALINA_BASE C:\apache-tomcat-6.0.35
 CATALINA_HOME C:\apache-tomcat-6.0.35
 JAVA_HOME C:\Java\jdk1.6.0_10
 classpath .;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar;%CATALINA_HOME%\common\lib\servlet-api.jar
 Path JAVA_HOME%\bin;%JAVA_HOME%\jre\bin

Answer 7

终于搞定了 在服务器里的context.xml 配置一下Context reloadable="true"就可以了