菜鸟紧急求助 初学struts 找不出错误
struts-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd">
<struts-config>
<data-sources />
<form-beans >
<form-bean name="loginForm" type="com.pdsu.cbx.LoginForm "></form-bean>
</form-beans>
<action-mappings >
<action path="/login" type="com.pdsu.cbx.LoginAction" name="loginForm">
<forward name="loginSucess" path="/welcome.jsp"></forward>
<forward name="loginFailure" path="/login.jsp"></forward>
</action>
</action-mappings>
<message-resources parameter="com.yourcompany.struts.ApplicationResources" />
</struts-config>
LoginAction.java
package com.pdsu.cbx;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
public class LoginAction extends Action {
public ActionForward execute(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
LoginForm loginForm=(LoginForm) form;
if(loginForm.getUsername().equals("admin")&&loginForm.getPassword().equals("123")){
return mapping.findForward("loginSucess");
}
else{
return mapping.findForward("loginFailure");
}
}
}
LoginForm.java
package com.pdsu.cbx;
import org.apache.struts.action.ActionForm;
public class LoginForm extends ActionForm {
private String username;
private String password;
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<html>
<head>
<title>My JSP 'login.jsp' starting page</title>
</head>
<body>
<form action="login.do" method="post">
username:<input type="text" name="username" ><br>
password:<input type="password" name="password"/><br>
<input type="submit" value="login"/>
</form>
</body>
</html>
错误提示
HTTP Status 500 -
--------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: java.lang.NullPointerException
org.apache.struts.action.RequestProcessor.processException(RequestProcessor.java:535)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:433)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause
java.lang.NullPointerException
com.pdsu.cbx.LoginAction.execute(LoginAction.java:21)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.22 logs.
[解决办法]
看看你的Action里面，单步进去。。
应该是这个Form得到的是Null
我的异常网推荐解决方案：The server encountered an internal error () that prevented it from fulfilling this request.,http://www.myexception.cn/java-web/317.html
