Problemas com EJB

[BLV_DOOM_JAVA]

Oi pessoal!

Eu estou estudando EJB pela apostila do curso FJ31 da Caelum…
Estou no exercicio do capitulo 7 - Aplicação Servidora e cliente…

Fiz o exercicio conforme descrito na apostila e estou tomando esse erro:

Exception in thread "main" javax.ejb.EJBException: java.lang.NullPointerException at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:63) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulInstanceInterceptor.invoke(StatefulInstanceInterceptor.java:83) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulContainer.dynamicInvoke(StatefulContainer.java:335) at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106) at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82) at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:809) at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:608) at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:406) at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:173) at org.jboss.remoting.MicroRemoteClientInvoker.invoke(MicroRemoteClientInvoker.java:163) at org.jboss.remoting.Client.invoke(Client.java:1634) at org.jboss.remoting.Client.invoke(Client.java:548) at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:67) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:53) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulRemoteProxy.invoke(StatefulRemoteProxy.java:139) at $Proxy1.addLivro(Unknown Source) at ClienteCarrinho.main(ClienteCarrinho.java:18) at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:67) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:53) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulRemoteProxy.invoke(StatefulRemoteProxy.java:139) at $Proxy1.addLivro(Unknown Source) at ClienteCarrinho.main(ClienteCarrinho.java:18) Caused by: java.lang.NullPointerException at br.com.caelum.loja.session.CarrinhoBean.addLivro(CarrinhoBean.java:18) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.ExtendedPersistenceContextPropagationInterceptor.invoke(ExtendedPersistenceContextPropagationInterceptor.java:57) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulInstanceInterceptor.invoke(StatefulInstanceInterceptor.java:83) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulContainer.dynamicInvoke(StatefulContainer.java:335) at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106) at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82) at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:809) at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:608) at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:406) at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:173)

Alguém sabe o que pode ser?

Obrigado.

[ErickRAR]

Caused by: java.lang.NullPointerException  
    at br.com.caelum.loja.session.CarrinhoBean.addLivro(CarrinhoBean.java:18)

Você está utilizando algo nesta linha que não está instanciado. Sempre que for utilizar um objeto, ele precisa estar instanciado antes, ou dará [color=red]NullPointerException[/color].

[caio_ferreira]

Deve estar faltando a anotação @EJB no declaração da variável CarrinhoBean, ou a anotação do bean (@Stateful ou @Stateless) na classe CarrinhoBean.

[BLV_DOOM_JAVA]

Deve estar faltando a anotação @EJB no declaração da variável CarrinhoBean, ou a anotação do bean (@Stateful ou @Stateless) na classe CarrinhoBean.

Eis como estão minhas classes…
Realmente não sei o que esta errado…

[code]package br.com.caelum.loja.entity;

import java.io.Serializable;

public class Livro implements Serializable {

private static final long serialVersionUID = 1L;

private String nome;
private double preco;

public String getNome() {
	return nome;
}
public void setNome(String nome) {
	this.nome = nome;
}
public double getPreco() {
	return preco;
}
public void setPreco(double preco) {
	this.preco = preco;
}

@Override
public String toString() {
	return "Livro [nome=" + nome + ", preco=" + preco + "]";
}

}
[/code]

[code]package br.com.caelum.loja.session;

import java.util.List;

import br.com.caelum.loja.entity.Livro;

public interface Carrinho {

void addLivro(Livro livro);
List<Livro> getLivros();
double getTotal();
void finalizaCompra();

}
[/code]

[code]package br.com.caelum.loja.session;

import java.util.List;

import javax.ejb.Remote;
import javax.ejb.Stateful;

import br.com.caelum.loja.entity.Livro;

@Stateful
@Remote(Carrinho.class)
public class CarrinhoBean implements Carrinho {

private List<Livro> livros;
private double total = 10.0;

public void addLivro(Livro livro) {
	System.out.println(livro);
	this.livros.add(livro);
	this.total += livro.getPreco();
	
	// apenas para ver alguma saída no "JBoss"
	System.out.printf("Livro %s adicionado com sucesso!", livro.getNome());
}

public List<Livro> getLivros() {
	return this.livros;
}

public double getTotal() {
	return this.total;
}

public void finalizaCompra() {
	for (Livro livro : this.livros) {
		System.out.println("Comprando livro: " + livro);
	}
}

}
[/code]

[code]import javax.naming.InitialContext;
import javax.naming.NamingException;

import br.com.caelum.loja.entity.Livro;
import br.com.caelum.loja.session.Carrinho;

public class ClienteCarrinho {

public static void main(String[] args) throws NamingException {
	InitialContext ic = new InitialContext();
	Carrinho carrinho = (Carrinho) ic.lookup("fj31-loja-ear/CarrinhoBean/remote");
	
	if(carrinho == null) {
		System.out.println("Esta nulo");
	} else {
		System.out.println("não esta nulo");
		System.out.println(carrinho.getTotal());
	}
	
	Livro livro1 = new Livro();
	livro1.setNome("Fausto");
	livro1.setPreco(45);
	
	System.out.println(livro1);
	
	System.out.println("Entrando do método.");
	carrinho.addLivro(livro1);
	System.out.println("Saindo do método.");
	
	Livro livro2 = new Livro();
	livro2.setNome("Pais e Filhos");
	livro2.setPreco(25);
	
	carrinho.addLivro(livro2);
	
	System.out.println("Total: " + carrinho.getTotal());
	
	carrinho.finalizaCompra();
}

}
[/code]

jndi.properties

java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory java.naming.provider.url=jnp://localhost:1099

Rodando o projeto eu tenho isso aqui:

não esta nulo 10.0 Livro [nome=Fausto, preco=45.0] Entrando do método. Exception in thread "main" javax.ejb.EJBException: java.lang.NullPointerException at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:63) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulInstanceInterceptor.invoke(StatefulInstanceInterceptor.java:83) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulContainer.dynamicInvoke(StatefulContainer.java:335) at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106) at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82) at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:809) at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:608) at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:406) at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:173) at org.jboss.remoting.MicroRemoteClientInvoker.invoke(MicroRemoteClientInvoker.java:163) at org.jboss.remoting.Client.invoke(Client.java:1634) at org.jboss.remoting.Client.invoke(Client.java:548) at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:67) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:53) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulRemoteProxy.invoke(StatefulRemoteProxy.java:139) at $Proxy1.addLivro(Unknown Source) at ClienteCarrinho.main(ClienteCarrinho.java:28) at org.jboss.aspects.remoting.InvokeRemoteInterceptor.invoke(InvokeRemoteInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.ClientTxPropagationInterceptor.invoke(ClientTxPropagationInterceptor.java:67) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.SecurityClientInterceptor.invoke(SecurityClientInterceptor.java:53) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.remoting.IsLocalInterceptor.invoke(IsLocalInterceptor.java:74) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulRemoteProxy.invoke(StatefulRemoteProxy.java:139) at $Proxy1.addLivro(Unknown Source) at ClienteCarrinho.main(ClienteCarrinho.java:28) Caused by: java.lang.NullPointerException at br.com.caelum.loja.session.CarrinhoBean.addLivro(CarrinhoBean.java:20) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.ExtendedPersistenceContextPropagationInterceptor.invoke(ExtendedPersistenceContextPropagationInterceptor.java:57) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulInstanceInterceptor.invoke(StatefulInstanceInterceptor.java:83) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateful.StatefulContainer.dynamicInvoke(StatefulContainer.java:335) at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106) at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82) at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:809) at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:608) at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:406) at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:173)

Por que?
Não sei o que ocorre.

Peço ajuda de vocês.

[ErickRAR]

O erro está quando você faz isso:

carrinho.addLivro(livro1);

Você tem um array em sua classe carrinhoBean que não está instanciado. Você tem que instanciar a lista também:

List<Livro> livros = new ArrayList<Livros>();

Depois disso poderá adicionar os livros sem problema.

[BLV_DOOM_JAVA]

[quote=ErickRAR]O erro está quando você faz isso:

carrinho.addLivro(livro1);

Você tem um array em sua classe carrinhoBean que não está instanciado. Você tem que instanciar a lista também:

List<Livro> livros = new ArrayList<Livros>();

Depois disso poderá adicionar os livros sem problema.[/quote]

Cara…fiquei até com vergonha agora.
Vlw mesmo…

Olhei um monte de coisa e não vi isso.

Vlw…problema resolvido.

To aprendendo EJB agora, mas isso é Java basico…que vergonha.

Vlw mesmo.