javax.persistence.EntityManager.merge()方法的使用及代码示例

x33g5p2x  于2022-01-18 转载在 其他  
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本文整理了Java中javax.persistence.EntityManager.merge()方法的一些代码示例，展示了EntityManager.merge()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。EntityManager.merge()方法的具体详情如下：
包路径：javax.persistence.EntityManager
类名称：EntityManager
方法名：merge

EntityManager.merge介绍

[英]Merge the state of the given entity into the current persistence context.
[中]将给定实体的状态合并到当前持久性上下文中。

代码示例

代码示例来源：origin: stackoverflow.com

@Stateless
public class BookService {

  @PersistenceContext
  private EntityManager em;

  public List<Book> list() {
    return em.createQuery("FROM Book", Book.class).getResultList();
  }

  public Book find(Integer id) {
    return em.find(Book.class, id);
  }

  public Integer save(Book book) {
    em.persist(book);
    return book.getId();
  }

  public void update(Book book) {
    em.merge(book);
  }

  public void delete(Book book) {
    em.remove(em.contains(book) ? book : em.merge(book));
  }

}

代码示例来源：origin: kiegroup/optaplanner

protected <S extends Score, E extends AbstractTestJpaEntity<S>> void findAssertAndChangeScore(
    Class<E> jpaEntityClass, Long id, S oldScore, S newScore) {
  try {
    transactionManager.begin();
    EntityManager em = entityManagerFactory.createEntityManager();
    E jpaEntity = em.find(jpaEntityClass, id);
    em.persist(jpaEntity);
    assertEquals(oldScore, jpaEntity.getScore());
    jpaEntity.setScore(newScore);
    jpaEntity = em.merge(jpaEntity);
    transactionManager.commit();
  } catch (NotSupportedException | SystemException | RollbackException | HeuristicRollbackException | HeuristicMixedException e) {
    throw new RuntimeException("Transaction failed.", e);
  }
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager em = getEntityManager();
  // Revision 1
  em.getTransaction().begin();
  BasicTestEntity1 entity = new BasicTestEntity1( "str1", 1 );
  em.persist( entity );
  em.getTransaction().commit();
  id = entity.getId();
  // Revision 2 - both properties (str1 and long1) should be marked as modified.
  em.getTransaction().begin();
  entity = em.find( BasicTestEntity1.class, entity.getId() );
  entity.setStr1( "str2" );
  entity = em.merge( entity );
  em.flush();
  entity.setLong1( 2 );
  entity = em.merge( entity );
  em.flush();
  em.getTransaction().commit();
  em.close();
}

代码示例来源：origin: Impetus/Kundera

public void testMerge(boolean useSameEm)
{
  EntityManager em = emf.createEntityManager();
  StudentCouchDBChar student = em.find(StudentCouchDBChar.class, getMaxValue(char.class));
  Assert.assertNotNull(student);
  Assert.assertEquals(getMaxValue(short.class), student.getAge());
  Assert.assertEquals(getMaxValue(String.class), student.getName());
  student.setName("Kuldeep");
  em.merge(student);
  if (!useSameEm)
  {
    em.close();
    em = emf.createEntityManager();
  }
  StudentCouchDBChar newStudent = em.find(StudentCouchDBChar.class, getMaxValue(char.class));
  Assert.assertNotNull(newStudent);
  Assert.assertEquals(getMaxValue(short.class), newStudent.getAge());
  Assert.assertEquals("Kuldeep", newStudent.getName());
}

代码示例来源：origin: Impetus/Kundera

/**
 * Test merge.
 */
private void testMerge()
{
  Person p = em.find(Person.class, "101");
  p.setPersonName("karthik");
  em.merge(p);
  em.clear();
  Person p1 = em.find(Person.class, "101");
  Assert.assertNotNull(p1);
  Assert.assertEquals("karthik", p1.getPersonName());
}

代码示例来源：origin: Impetus/Kundera

/**
 * Test update.
 */
private void testUpdate()
{
  PersonMTM p1 = em.find(PersonMTM.class, "p1");
  p1.setPersonName("Devender");
  em.merge(p1);
  em.clear();
  PersonMTM p = em.find(PersonMTM.class, "p1");
  Assert.assertEquals("Devender", p.getPersonName());
}

代码示例来源：origin: Impetus/Kundera

public void testMerge(boolean useSameEm)
{
  EntityManager em = emf.createEntityManager();
  StudentCouchDBDate student = em.find(StudentCouchDBDate.class, getMaxValue(Date.class));
  Assert.assertNotNull(student);
  Assert.assertEquals(getMaxValue(short.class), student.getAge());
  Assert.assertEquals(getMaxValue(String.class), student.getName());
  student.setName("Kuldeep");
  em.merge(student);
  if (!useSameEm)
  {
    em.close();
    em = emf.createEntityManager();
  }
  StudentCouchDBDate newStudent = em.find(StudentCouchDBDate.class, getMaxValue(Date.class));
  Assert.assertNotNull(newStudent);
  Assert.assertEquals(getMaxValue(short.class), newStudent.getAge());
  Assert.assertEquals("Kuldeep", newStudent.getName());
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager em = getEntityManager();
  // Revision 1
  em.getTransaction().begin();
  StrTestEntity entity = new StrTestEntity( "x" );
  em.persist( entity );
  em.getTransaction().commit();
  id = entity.getId();
  // Revision 2
  em.getTransaction().begin();
  entity = em.find( StrTestEntity.class, entity.getId() );
  entity.setStr( "y" );
  entity = em.merge( entity );
  em.getTransaction().commit();
  em.close();
}

代码示例来源：origin: hibernate/hibernate-orm

private void saveUpdateAndRemoveEntity(EntityManager entityManager, Integer id) {
    EntityTransaction transaction = entityManager.getTransaction();

    transaction.begin();
    IntNoAutoIdTestEntity entity = new IntNoAutoIdTestEntity( 0, id );
    entityManager.persist( entity );
    assertEquals( id, entity.getId() );
    transaction.commit();

    transaction.begin();
    entity = entityManager.find( IntNoAutoIdTestEntity.class, id );
    entity.setNumVal( 1 );
    entity = entityManager.merge( entity );
    assertEquals( id, entity.getId() );
    transaction.commit();

    transaction.begin();
    entity = entityManager.find( IntNoAutoIdTestEntity.class, id );
    assertNotNull( entity );
    entityManager.remove( entity );
    transaction.commit();
  }
}

代码示例来源：origin: Impetus/Kundera

/**
 * Test merge.
 */
private void testMerge()
{
  Person p = em.find(Person.class, "101");
  p.setPersonName("karthik");
  em.merge(p);
  em.clear();
  Person p1 = em.find(Person.class, "101");
  Assert.assertNotNull(p1);
  Assert.assertEquals("karthik", p1.getPersonName());
}

代码示例来源：origin: Impetus/Kundera

public void testMerge(boolean useSameEm)
{
  EntityManager em = emf.createEntityManager();
  StudentMongoTimestamp student = em.find(StudentMongoTimestamp.class, getMaxValue(Timestamp.class));
  Assert.assertNotNull(student);
  Assert.assertEquals(getMaxValue(short.class), student.getAge());
  Assert.assertEquals(getMaxValue(String.class), student.getName());
  student.setName("Kuldeep");
  em.merge(student);
  if (!useSameEm)
  {
    em.close();
    em = emf.createEntityManager();
  }
  StudentMongoTimestamp newStudent = em.find(StudentMongoTimestamp.class, getMaxValue(Timestamp.class));
  Assert.assertNotNull(newStudent);
  Assert.assertEquals(getMaxValue(short.class), newStudent.getAge());
  Assert.assertEquals("Kuldeep", newStudent.getName());
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager em = getEntityManager();
  // Revision 1 - add
  em.getTransaction().begin();
  ObjectUserTypeEntity entity = new ObjectUserTypeEntity( "builtInType1", "stringUserType1" );
  em.persist( entity );
  em.getTransaction().commit();
  id = entity.getId();
  // Revision 2 - modify
  em.getTransaction().begin();
  entity = em.find( ObjectUserTypeEntity.class, entity.getId() );
  entity.setUserType( 2 );
  entity = em.merge( entity );
  em.getTransaction().commit();
  // Revision 3 - remove
  em.getTransaction().begin();
  entity = em.find( ObjectUserTypeEntity.class, entity.getId() );
  em.remove( entity );
  em.getTransaction().commit();
  em.close();
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager em = getEntityManager();
  // Revision 1 - Adding two entities
  em.getTransaction().begin();
  StrTestEntity ste1 = new StrTestEntity( "x" );
  StrTestEntity ste2 = new StrTestEntity( "y" );
  em.persist( ste1 );
  em.persist( ste2 );
  steId1 = ste1.getId();
  steId2 = ste2.getId();
  em.getTransaction().commit();
  // Revision 2 - Adding first and removing second entity
  em.getTransaction().begin();
  ste1 = em.find( StrTestEntity.class, steId1 );
  ste2 = em.find( StrTestEntity.class, steId2 );
  ste1.setStr( "z" );
  em.remove( ste2 );
  em.getTransaction().commit();
  // Revision 3 - Modifying and removing the same entity.
  em.getTransaction().begin();
  ste1 = em.find( StrTestEntity.class, steId1 );
  ste1.setStr( "a" );
  em.merge( ste1 );
  em.remove( ste1 );
  em.getTransaction().commit();
}

代码示例来源：origin: Impetus/Kundera

/**
 * Test merge.
 */
private void testMerge()
{
  Person p = em.find(Person.class, "101");
  p.setPersonName("karthik");
  em.merge(p);
  em.clear();
  Person p1 = em.find(Person.class, "101");
  Assert.assertNotNull(p1);
  Assert.assertEquals("karthik", p1.getPersonName());
}

代码示例来源：origin: Impetus/Kundera

public void testMerge(boolean useSameEm)
{
  EntityManager em = emf.createEntityManager();
  StudentBytePrimitive student = em.find(StudentBytePrimitive.class, getMaxValue(byte.class));
  Assert.assertNotNull(student);
  Assert.assertEquals(getMaxValue(short.class), student.getAge());
  Assert.assertEquals(getMaxValue(String.class), student.getName());
  student.setName("Kuldeep");
  em.merge(student);
  if (!useSameEm)
  {
    em.close();
    em = emf.createEntityManager();
  }
  StudentBytePrimitive newStudent = em.find(StudentBytePrimitive.class, getMaxValue(byte.class));
  Assert.assertNotNull(newStudent);
  Assert.assertEquals(getMaxValue(short.class), newStudent.getAge());
  Assert.assertEquals("Kuldeep", newStudent.getName());
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager em = getEntityManager();
  // Revision 1
  em.getTransaction().begin();
  StrTestEntity emptyEntity = new StrTestEntity( "" );
  em.persist( emptyEntity );
  StrTestEntity nullEntity = new StrTestEntity( null );
  em.persist( nullEntity );
  em.getTransaction().commit();
  emptyId = emptyEntity.getId();
  nullId = nullEntity.getId();
  em.close();
  em = getEntityManager();
  // Should not generate revision after NULL to "" modification and vice versa on Oracle.
  em.getTransaction().begin();
  emptyEntity = em.find( StrTestEntity.class, emptyId );
  emptyEntity.setStr( null );
  em.merge( emptyEntity );
  nullEntity = em.find( StrTestEntity.class, nullId );
  nullEntity.setStr( "" );
  em.merge( nullEntity );
  em.getTransaction().commit();
  em.close();
}

代码示例来源：origin: hibernate/hibernate-orm

owning1 = em.find( ManyToOneOwning.class, owning1.getId() );
em.remove( owning1 );
em.getTransaction().commit();
owning2 = em.find( ManyToOneOwning.class, owning2.getId() );
owning2.setData( "data2modified" );
em.merge( owning2 );
em.getTransaction().commit();

代码示例来源：origin: Impetus/Kundera

public void testMerge(boolean useSameEm)
{
  EntityManager em = emf.createEntityManager();
  StudentCouchDBBigDecimal student = em.find(StudentCouchDBBigDecimal.class, getMaxValue(BigDecimal.class));
  Assert.assertNotNull(student);
  Assert.assertEquals(getMaxValue(short.class), student.getAge());
  Assert.assertEquals(getMaxValue(String.class), student.getName());
  student.setName("Kuldeep");
  em.merge(student);
  if (!useSameEm)
  {
    em.close();
    em = emf.createEntityManager();
  }
  StudentCouchDBBigDecimal newStudent = em.find(StudentCouchDBBigDecimal.class, getMaxValue(BigDecimal.class));
  Assert.assertNotNull(newStudent);
  Assert.assertEquals(getMaxValue(short.class), newStudent.getAge());
  Assert.assertEquals("Kuldeep", newStudent.getName());
}

代码示例来源：origin: hibernate/hibernate-orm

@Test
@Priority(10)
public void initData() {
  EntityManager entityManager = getOrCreateEntityManager();
  try {
    // Revision 1
    SimpleEntity se = new SimpleEntity();
    se.setData( "data" );
    entityManager.getTransaction().begin();
    entityManager.persist( se );
    entityManager.getTransaction().commit();
    entityManager.clear();
    entityId = se.getId();
    // Revision 2
    entityManager.getTransaction().begin();
    se = entityManager.find( SimpleEntity.class, se.getId() );
    se.setData( "data2" );
    entityManager.merge( se );
    entityManager.getTransaction().commit();
    // Revision 3
    entityManager.getTransaction().begin();
    se = entityManager.find( SimpleEntity.class, se.getId() );
    entityManager.remove( se );
    entityManager.getTransaction().commit();
  }
  finally {
    entityManager.close();
  }
}

代码示例来源：origin: hibernate/hibernate-orm

final Simple simple = entityManager.find( Simple.class, 1 );
  simple.getEmbeddedMap().put( "3", "Three" );
  entityManager.merge( simple );
} );
  final Simple simple = entityManager.find( Simple.class, 1 );
  simple.getEmbeddedMap().remove( "1" );
  simple.getEmbeddedMap().remove( "2" );
  entityManager.merge( simple );
} );
  final Simple simple = entityManager.find( Simple.class, 1 );
  simple.getEmbeddedMap().remove( "3" );
  simple.getEmbeddedMap().put( "3", "Three-New" );
  entityManager.merge( simple );
} );
  final Simple simple = entityManager.find( Simple.class, 1 );
  simple.getEmbeddedMap().clear();
  entityManager.merge( simple );
} );

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