Struts

<?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">
<filter>
<filter-name>f1</filter-name>
<filter-class>org.apache.struts2.dispatcher
.FilterDispatcher
</filter-class>
</filter>
<filter-mapping>
<filter-name>f1</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>

<%@taglib uri="/struts-tags" prefix="s"%>
<s:form action="login">
<s:textfield name="name" label="Name"/>
<s:password name="password" 
label="Password"/>
<s:submit value="Login"/>
</s:form>

<!DOCTYPE struts PUBLIC 
"-//Apache Software Foundation
//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<package name="demo">
<result-types>
<result-type name="dispatcher"
class="mypack.MyResult" default="true"/>
</result-types>
<interceptors>
<interceptor name="paramSetter" 
class="mypack.MyInterceptor"/>
</interceptors>
<action name="login" class="mypack.LoginAction">
<interceptor-ref name="paramSetter"/>
<result name="success">/hello.jsp</result>
<result name="failure">/relogin.jsp</result>
</action>
</package>
</struts>

package mypack;
import javax.servlet.*;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2
.ActionInvocation;
import com.opensymphony.xwork2.Result;
public class MyResult implements Result {
private String page;
public static final String DEFAULT_PARAM="page";
public void execute(ActionInvocation ai) 
	throws Exception {
ServletRequest request=ServletActionContext
	.getRequest();
ServletResponse response=ServletActionContext
	.getResponse();
RequestDispatcher rd=request
	.getRequestDispatcher(page);
rd.forward(request,response);
}
public void setPage(String page) {
this.page = page;
}
}

package mypack;
import java.util.Enumeration;
import javax.servlet.ServletRequest;
import org.apache.struts2
.ServletActionContext;
import com.opensymphony.xwork2
.ActionInvocation;
import com.opensymphony.xwork2
.interceptor.Interceptor;
import com.opensymphony.xwork2
.util.ValueStack;
public class MyInterceptor implements
	Interceptor {
public void destroy() { }
public void init() { }
public String intercept(ActionInvocation ai)
	throws Exception {
ServletRequest request=ServletActionContext
	.getRequest();
ValueStack vs=ai.getStack();
Enumeration<String> e=request
	.getParameterNames();
while(e.hasMoreElements())
{
String pName=e.nextElement();
System.out.println(pName+"\t"+pValue);
vs.setValue(pName,pValue );
}String str=ai.invoke();
return str;
}

}

package mypack;
public class LoginAction {
private String name,password;
public String execute(){
if(name.startsWith("a")&&password
	.startsWith("b"))
return "success";
else
return "failure";
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}

<%@taglib uri="/struts-tags" prefix="s"%>
<b>Welcome, <s:property value="name"/></b>

<b>Invalid UserName and Password !</b>
<jsp:include page="index.jsp"/>