Question

我在hibernate项目上做了几个测试用例：

当我打电话

EntityManager em = getEntityManager();
em.find(Foo.class, 1)

我按照预期得到了实体，但是当我调用时：

EntityManager em = getEntityManager();
em.find(Foo.class, 1, LockModeType.WRITE)

我变空了。另外，当我做：

EntityManager em = getEntityManager();
Foo foo = em.find(Foo.class, 1)
em.lock(foo, LockModeType.WRITE);

我正在获取该对象，并且它正如我所期望的那样工作。

编辑：

@javax.persistence.Entity
@Table(name="foo")
static class Foo implements Serializable {
    @Id private Integer id;
    private String code;
    @Version private Integer version;

    public Foo() {
    }
            ........        
}

我的依赖项：

<dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>3.5.5-Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>4.1.0.Final</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>3.5.0-Beta-2</version>
    </dependency>
    <dependency>
        <groupId>jboss</groupId>
        <artifactId>jboss</artifactId>
        <version>4.2.3.GA</version>
        <scope>provided</scope>
    </dependency>

你能给我一点意见吗？

Answer 1

我无法重现。使用以下实体：

@Entity
public class Foo {
    @Id private Integer id;
    private String name;
    @Version private Integer version;
    ...
}

以下代码段正常运作：

EntityManager em = getEntityManager();
Foo foo = em.find(Foo.class, 1, LockModeType.WRITE); 
assertNotNull(foo);
foo.setName("baz");
em.flush();

使用乐观锁定读取和更新实体，版本更新：

10:21:42.223 [main] DEBUG org.hibernate.SQL - select foo0_.id as id25_0_, foo0_.name as name25_0_, foo0_.version as version25_0_ from Foo foo0_ where foo0_.id=?
10:21:42.225 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 1
10:21:42.229 [main] TRACE org.hibernate.type.StringType - returning 'bar' as column: name25_0_
10:21:42.230 [main] TRACE org.hibernate.type.LongType - returning '0' as column: version25_0_
10:21:42.246 [main] DEBUG org.hibernate.SQL - update Foo set name=?, version=? where id=? and version=?
10:21:42.248 [main] TRACE org.hibernate.type.StringType - binding 'baz' to parameter: 1
10:21:42.249 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 2
10:21:42.249 [main] TRACE org.hibernate.type.LongType - binding '1' to parameter: 3
10:21:42.250 [main] TRACE org.hibernate.type.LongType - binding '0' to parameter: 4

使用Hibernate 3.5.5-Final测试。

你不使用相同版本（由于像HHH-5032这样的问题我明确地提到过它）。请尝试使用以下依赖项（您不需要指定对hibernate-core工件的依赖关系，您将获得它的传递性）：

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>4.1.0.Final</version>
</dependency>
<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-entitymanager</artifactId>
    <version>3.5.5-Final</version>
</dependency>
<dependency>
    <groupId>jboss</groupId>
    <artifactId>jboss</artifactId>
    <version>4.2.3.GA</version>
    <scope>provided</scope>
</dependency>

jpa 2 hibernate在EntityManager.find上设置锁定

1 个答案: