Problem with attributes backing bean

[cesar vasde]

You see, I have the following exceptions

excepción 

javax.servlet.ServletException: java.lang.NullPointerException
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:325)


causa raíz 

javax.faces.el.EvaluationException: java.lang.NullPointerException
	javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102)
	com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
	javax.faces.component.UICommand.broadcast(UICommand.java:315)
	javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787)
	javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:928)
	com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
	com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)


causa raíz 

java.lang.NullPointerException
	com.web.vista.UsuarioBean.login(UsuarioBean.java:77)
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	java.lang.reflect.Method.invoke(Unknown Source)
	org.apache.el.parser.AstValue.invoke(AstValue.java:191)
	org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276)
	com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
	javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
	com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
	javax.faces.component.UICommand.broadcast(UICommand.java:315)
	javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:787)
	javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:928)
	com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
	com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
	com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
	javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)

This is the bean

@ManagedBean(name="usuarioBean")
@SessionScoped
public class UsuarioBean implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = 5236524407250186919L;
	private String id;
	private String nombres;
	private String apellidos;
	private int edad;
	private String user;
	private String pass;
	private UsuarioController usuarioController;

//Getters and Setters

public String login(){
		System.out.println("user: "+user);
		System.out.println("pass: "+pass);
		if(user.equals("cesar") && pass.equals("cesar"))
			return "success";
		else
			return "failed";
	}

faces-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<faces-config
    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-facesconfig_2_0.xsd"
    version="2.0">
<managed-bean>
  		<managed-bean-name>usuarioBean</managed-bean-name>
		<managed-bean-class>com.web.vista.UsuarioBean</managed-bean-class>
		<managed-bean-scope>session</managed-bean-scope>
		<managed-property>
			<property-name>usuarioController</property-name>
			<property-class></property-class>
			<value>#{usuarioController}</value>		 
		</managed-property>
  	</managed-bean>
  	<navigation-rule>
  		<from-view-id>/login.xhtml</from-view-id>
  		<navigation-case>
  			<from-action>#{usuarioBean.login}</from-action>
  			<from-outcome>success</from-outcome>
  			<to-view-id>/index.xhtml</to-view-id>
  		</navigation-case>
  		<navigation-case>
  			<from-action>#{usuarioBean.login}</from-action>
  			<from-outcome>failed</from-outcome>
  			<to-view-id>/login.xhtml</to-view-id>
  		</navigation-case>
  	</navigation-rule>
</faces-config>

The values that print in console are:

user: null
pass: null

As you can see, the fields of backing bean are null even though the xhtml page I put some value on them


What do you think is the problem?

[Tim Holloway]

You are getting the NullPointerException because you are attempting to invoke the equals() method on something that you already know is a null string (since you just printed it).

Normally, I'd expect the fields to be set to empty strings as part of the JSF request process, but you didn't include the actual page definition, so I can't tell whether you have your page form setup properly.

Aside from that, the technical name for "user-defined login" is Security Hole.

[naveen gupta]

The values you are entering in the GUI are not getting stored in the variables you defined in the backing bean
Put up some log statements and work in that direction to see why the values are not getting entered in the variables of JSF backing bean
best of luck