EJB

package de.test.gwt;
import javax.ejb.Remote;

@Remote
public interface SampleBeanRemote {

    public String hello(String name) throws Exception;
    public String[] getNames();
    public String createCompany(String text) throws Exception;
    public Company getCompany();

}




package de.test.gwt;

import java.util.List;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;

@Stateless
public class SampleBean implements SampleBeanRemote {

    private @PersistenceContext
    EntityManager entityManager;

    public SampleBean() {
    }

    public String createCompany(String text) throws Exception {
        if (entityManager.find(Company.class, text) != null) {
            throw new Exception("Name bereits vorhanden");
        } else {

            Company company = new Company(text);

            Adress adress1 = new Adress("Google Street View Street 3");

            Adress adress2 = new Adress("Elch Street 23");

            company.addAdress(adress1);
            company.addAdress(adress2);

            entityManager.persist(company);

            return company.getName();
        }
    }


    public Company getCompany() {
        Query query = entityManager
                .createQuery("Select c from Company c");

        @SuppressWarnings("unchecked")
        List<Company> companyList = (List<Company>) query
                .getResultList();

        return companyList.get(0);
    }
}




package de.test.gwt;

import java.io.Serializable;
import java.util.Collection;
import java.util.Vector;

import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.OneToMany;

@Entity
public class Company implements Serializable{

    private static final long serialVersionUID = 1L;

    @Id
    private String name;
    @OneToMany(cascade={CascadeType.PERSIST})
    private Collection<Adress> adresses = new Vector<Adress>();


    public Company(){

    }

    public Company(String name){
        this.setName(name);
    }

    public void addAdress(Adress adress) {
        adresses.add(adress);
    }

    public Collection<Adress> getAdress() {
        return adresses;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

}



package de.test.gwt;

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Adress implements Serializable{


    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String street;

    public Adress() {

    }

    public Adress(String street) {
        this.street = street;
    }

    public void setName(String street) {
        this.street = street;
    }

    public String getName() {
        return street;
    }

    public void setId(int id) {
        this.id = id;
    }

    public int getId() {
        return id;
    }

}