:index-group: Proxy Beans
:jbake-type: page
:jbake-status: status=published
= Implementação dinâmica de DAO

Muitos aspectos dos Data Access Objects (DAOs) são muito repetitivos e
boiler plate. Como um recurso divertido e experimental, o TomEE suporta
implementar dinamicamente uma interface que é vista como tendo métodos padrão no estilo DAO.

A interface deve ser anotada com @PersistenceContext para definir
qual EntityManager usar.

Os métodos devem respeitar estas convenções:

* void save(Foo foo): persistir foo
* Foo update(Foo foo): merge foo
* void delete(Foo foo): remover foo, se foo for desconectado, ele tenta
anexá-lo.
* Collection|Foo namedQuery(String name[, Map<String, ?> params, int
first, int max]): executar a consulta nomeada chamada name, params contém
ligações, first e max são usadas para paginação. Últimos três parâmetros
são opcionais.
* Collection|Foo nativeQuery(String name[, Map<String, ?> params, int
first, int max]): executar a consulta nativa chamada name, params contém
ligações, first e max são usadas para paginação. Últimos três parâmetros
são opcionais.
* Collection|Foo query(String value [, Map<String, ?> params, int first,
int max]): executar a consulta colocada como primeiro parâmetro, params contém
ligações, first e max são usadas para paginação. Últimos três parâmetros
são opcionais.
* Collection findAll([int first, int max]): Encontre todos os Foo, os parâmetros são
usado para paginação.
* Collection findByBar1AndBar2AndBar3(<bar 1 type> bar1, <bar 2 type>
bar2, bar3 [, int first, int max]): encontre todos os Foo com campo especificado
valores para bar1, bar2, bar3.

O localizador dinâmico pode ter pode ter quantas constantes de campo você quiser. Para
String like é usado e para outro tipo igual é usado.

== Exemplo

=== User

....
package org.superbiz.dynamic;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;

@Entity
@NamedQueries({
        @NamedQuery(name = "dynamic-ejb-impl-test.query", query = "SELECT u FROM User AS u WHERE u.name LIKE :name"),
        @NamedQuery(name = "dynamic-ejb-impl-test.all", query = "SELECT u FROM User AS u")
})
public class User {
    @Id
    @GeneratedValue
    private long id;
    private String name;
    private int age;

    public long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }
}
....

=== UserDao

....
package org.superbiz.dynamic;


import javax.ejb.Stateless;
import javax.persistence.PersistenceContext;
import java.util.Collection;
import java.util.Map;

@Stateless
@PersistenceContext(name = "dynamic")
public interface UserDao {
    User findById(long id);

    Collection<User> findByName(String name);

    Collection<User> findByNameAndAge(String name, int age);

    Collection<User> findAll();

    Collection<User> findAll(int first, int max);

    Collection<User> namedQuery(String name, Map<String, ?> params, int first, int max);

    Collection<User> namedQuery(String name, int first, int max, Map<String, ?> params);

    Collection<User> namedQuery(String name, Map<String, ?> params);

    Collection<User> namedQuery(String name);

    Collection<User> query(String value, Map<String, ?> params);

    void save(User u);

    void delete(User u);

    User update(User u);
}
....

=== persistence.xml

....
<persistence version="2.0"
             xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="
      http://java.sun.com/xml/ns/persistence
      http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">
  <persistence-unit name="dynamic" transaction-type="JTA">
    <jta-data-source>jdbc/dynamicDB</jta-data-source>
    <class>org.superbiz.dynamic.User</class>
    <properties>
      <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
    </properties>
  </persistence-unit>
</persistence>
....

=== DynamicUserDaoTest

....
package org.superbiz.dynamic;

import junit.framework.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import javax.ejb.EJBException;
import javax.ejb.Stateless;
import javax.ejb.embeddable.EJBContainer;
import javax.naming.Context;
import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.PersistenceContext;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import static junit.framework.Assert.assertEquals;
import static junit.framework.Assert.assertNotNull;
import static junit.framework.Assert.assertTrue;

public class DynamicUserDaoTest {
    private static UserDao dao;
    private static Util util;

    @BeforeClass
    public static void init() throws Exception {
        final Properties p = new Properties();
        p.put("jdbc/dynamicDB", "new://Resource?type=DataSource");
        p.put("jdbc/dynamicDB.JdbcDriver", "org.hsqldb.jdbcDriver");
        p.put("jdbc/dynamicDB.JdbcUrl", "jdbc:hsqldb:mem:moviedb");
        p.put("jdbc/dynamicDB.UserName", "sa");
        p.put("jdbc/dynamicDB.Password", "");

        final Context context = EJBContainer.createEJBContainer(p).getContext();
        dao = (UserDao) context.lookup("java:global/dynamic-dao-implementation/UserDao");
        util = (Util) context.lookup("java:global/dynamic-dao-implementation/Util");

        util.init(); // init database
    }

    @Test
    public void simple() {
        User user = dao.findById(1);
        assertNotNull(user);
        assertEquals(1, user.getId());
    }

    @Test
    public void findAll() {
        Collection<User> users = dao.findAll();
        assertEquals(10, users.size());
    }

    @Test
    public void pagination() {
        Collection<User> users = dao.findAll(0, 5);
        assertEquals(5, users.size());

        users = dao.findAll(6, 1);
        assertEquals(1, users.size());
        assertEquals(7, users.iterator().next().getId());
    }

    @Test
    public void persist() {
        User u = new User();
        dao.save(u);
        assertNotNull(u.getId());
        util.remove(u);
    }

    @Test
    public void remove() {
        User u = new User();
        dao.save(u);
        assertNotNull(u.getId());
        dao.delete(u);
        try {
            dao.findById(u.getId());
            Assert.fail();
        } catch (EJBException ee) {
            assertTrue(ee.getCause() instanceof NoResultException);
        }
    }

    @Test
    public void merge() {
        User u = new User();
        u.setAge(1);
        dao.save(u);
        assertEquals(1, u.getAge());
        assertNotNull(u.getId());

        u.setAge(2);
        dao.update(u);
        assertEquals(2, u.getAge());

        dao.delete(u);
    }

    @Test
    public void oneCriteria() {
        Collection<User> users = dao.findByName("foo");
        assertEquals(4, users.size());
        for (User user : users) {
            assertEquals("foo", user.getName());
        }
    }

    @Test
    public void twoCriteria() {
        Collection<User> users = dao.findByNameAndAge("bar-1", 1);
        assertEquals(1, users.size());

        User user = users.iterator().next();
        assertEquals("bar-1", user.getName());
        assertEquals(1, user.getAge());
    }

    @Test
    public void query() {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("name", "foo");

        Collection<User> users = dao.namedQuery("dynamic-ejb-impl-test.query", params, 0, 100);
        assertEquals(4, users.size());

        users = dao.namedQuery("dynamic-ejb-impl-test.query", params);
        assertEquals(4, users.size());

        users = dao.namedQuery("dynamic-ejb-impl-test.query", params, 0, 2);
        assertEquals(2, users.size());

        users = dao.namedQuery("dynamic-ejb-impl-test.query", 0, 2, params);
        assertEquals(2, users.size());

        users = dao.namedQuery("dynamic-ejb-impl-test.all");
        assertEquals(10, users.size());

        params.remove("name");
        params.put("age", 1);
        users = dao.query("SELECT u FROM User AS u WHERE u.age = :age", params);
        assertEquals(3, users.size());
    }

    @Stateless
    public static class Util {
        @PersistenceContext
        private EntityManager em;

        public void remove(User o) {
            em.remove(em.find(User.class, o.getId()));
        }

        public void init() {
            for (int i = 0; i < 10; i++) {
                User u = new User();
                u.setAge(i % 4);
                if (i % 3 == 0) {
                    u.setName("foo");
                } else {
                    u.setName("bar-" + i);
                }
                em.persist(u);
            }
        }
    }
}
....

== Executando

....
-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running org.superbiz.dynamic.DynamicUserDaoTest
Apache OpenEJB 4.0.0-beta-1    build: 20111002-04:06
http://tomee.apache.org/
INFO - openejb.home = /Users/dblevins/examples/dynamic-dao-implementation
INFO - openejb.base = /Users/dblevins/examples/dynamic-dao-implementation
INFO - Using 'javax.ejb.embeddable.EJBContainer=true'
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Configuring Service(id=jdbc/dynamicDB, type=Resource, provider-id=Default JDBC Database)
INFO - Found EjbModule in classpath: /Users/dblevins/examples/dynamic-dao-implementation/target/classes
INFO - Found EjbModule in classpath: /Users/dblevins/examples/dynamic-dao-implementation/target/test-classes
INFO - Beginning load: /Users/dblevins/examples/dynamic-dao-implementation/target/classes
INFO - Beginning load: /Users/dblevins/examples/dynamic-dao-implementation/target/test-classes
INFO - Configuring enterprise application: /Users/dblevins/examples/dynamic-dao-implementation
INFO - Configuring Service(id=Default Stateless Container, type=Container, provider-id=Default Stateless Container)
INFO - Auto-creating a container for bean UserDao: Container(type=STATELESS, id=Default Stateless Container)
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean org.superbiz.dynamic.DynamicUserDaoTest: Container(type=MANAGED, id=Default Managed Container)
INFO - Configuring PersistenceUnit(name=dynamic)
INFO - Auto-creating a Resource with id 'jdbc/dynamicDBNonJta' of type 'DataSource for 'dynamic'.
INFO - Configuring Service(id=jdbc/dynamicDBNonJta, type=Resource, provider-id=jdbc/dynamicDB)
INFO - Adjusting PersistenceUnit dynamic <non-jta-data-source> to Resource ID 'jdbc/dynamicDBNonJta' from 'null'
INFO - Enterprise application "/Users/dblevins/examples/dynamic-dao-implementation" loaded.
INFO - Assembling app: /Users/dblevins/examples/dynamic-dao-implementation
INFO - PersistenceUnit(name=dynamic, provider=org.apache.openjpa.persistence.PersistenceProviderImpl) - provider time 417ms
INFO - Jndi(name="java:global/dynamic-dao-implementation/UserDao!org.superbiz.dynamic.UserDao")
INFO - Jndi(name="java:global/dynamic-dao-implementation/UserDao")
INFO - Jndi(name="java:global/dynamic-dao-implementation/Util!org.superbiz.dynamic.DynamicUserDaoTest$Util")
INFO - Jndi(name="java:global/dynamic-dao-implementation/Util")
INFO - Jndi(name="java:global/EjbModule346613126/org.superbiz.dynamic.DynamicUserDaoTest!org.superbiz.dynamic.DynamicUserDaoTest")
INFO - Jndi(name="java:global/EjbModule346613126/org.superbiz.dynamic.DynamicUserDaoTest")
INFO - Created Ejb(deployment-id=UserDao, ejb-name=UserDao, container=Default Stateless Container)
INFO - Created Ejb(deployment-id=Util, ejb-name=Util, container=Default Stateless Container)
INFO - Created Ejb(deployment-id=org.superbiz.dynamic.DynamicUserDaoTest, ejb-name=org.superbiz.dynamic.DynamicUserDaoTest, container=Default Managed Container)
INFO - Started Ejb(deployment-id=UserDao, ejb-name=UserDao, container=Default Stateless Container)
INFO - Started Ejb(deployment-id=Util, ejb-name=Util, container=Default Stateless Container)
INFO - Started Ejb(deployment-id=org.superbiz.dynamic.DynamicUserDaoTest, ejb-name=org.superbiz.dynamic.DynamicUserDaoTest, container=Default Managed Container)
INFO - Deployed Application(path=/Users/dblevins/examples/dynamic-dao-implementation)
WARN - Meta class "org.superbiz.dynamic.User_" for entity class org.superbiz.dynamic.User can not be registered with following exception "java.security.PrivilegedActionException: java.lang.ClassNotFoundException: org.superbiz.dynamic.User_"
WARN - Query "SELECT u FROM User AS u WHERE u.name LIKE :name" is removed from cache  excluded permanently. Query "SELECT u FROM User AS u WHERE u.name LIKE :name" is not cached because it uses pagination..
Tests run: 9, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 2.471 sec

Results :

Tests run: 9, Failures: 0, Errors: 0, Skipped: 0
....