Hibernate 5字节码增强关联管理只在一个方向上工作

Question

我有2个JPA实体像这样映射:

@MappedSuperclass
public class AbstractEntity {
    private static final String INCREMENT_STRATEGY = "increment";
    private static final String INCREMENT_ID_GENERATOR_NAME = "INCREMENT_ID_GENERATOR";
    
    @Id
    @GenericGenerator(name = INCREMENT_ID_GENERATOR_NAME, strategy = INCREMENT_STRATEGY)
    @GeneratedValue(generator = INCREMENT_ID_GENERATOR_NAME)
    private Long id;
    public AbstractEntity() {
        super();
    }
    
    public Long getId() {
        return id;
    }
}
@Entity
public class Department extends AbstractEntity{
    
    
    @OneToMany(cascade = CascadeType.ALL, mappedBy = "department")
    private List<Employee> employees = new ArrayList<Employee>();
    public void setEmployees(List<Employee> employees) {
        this.employees = employees;
    }
    
    public List<Employee> getEmployees() {
        return employees;
    }
}
@Entity
public class Employee extends AbstractEntity {
    @ManyToOne(optional = true, cascade= CascadeType.ALL)
    @JoinColumn(name = "DEPARTMENT_ID")
    private Department department;
    public void setDepartment(Department department) {
        this.department = department;
    }
    public Department getDepartment() {
        return department;
    }
}

所有类都使用hibernate增强maven插件进行字节码增强:

<build>
    <plugins>
        <plugin>
            <groupId>org.hibernate.orm.tooling</groupId>
            <artifactId>hibernate-enhance-maven-plugin</artifactId>
            <version>5.2.2.Final</version>
            <dependencies>
                <dependency>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-entitymanager</artifactId>
                    <version>5.2.2.Final</version>
                </dependency>
            </dependencies>
            <configuration>
                <enableDirtyTracking>true</enableDirtyTracking>
                <enableLazyInitialization>true</enableLazyInitialization>
                <enableAssociationManagement>true</enableAssociationManagement>
            </configuration>
        </plugin>
    </plugins>
</build>

我运行两个测试来验证增强类是否正常工作:

@Test
public void test1() {
    Department department = new Department();
    Employee employee = new Employee();
    department.getEmployees().add(employee);
    assertThat(employee.getDepartment(), is(not(nullValue())));
}
@Test
public void test2() {
    Department department = new Department();
    Employee employee = new Employee();
    employee.setDepartment(department);
    assertThat(department.getEmployees().size(), is(1));
    assertThat(department.getEmployees().get(0), is(employee));
}

只有第二个测试成功通过，因此当关联通过父节点的集合操作时，子节点的父节点字段没有更新，而在Hibernate ORM 5.2.3中。最终用户指南

字节码增强的双向关联管理通过管理"另一边"使第一个示例工作。当一方被操纵时，双向关联的。

此处引用"第一个例子";

204。错误的正常Java用法

为什么在我的test1的情况下，关联管理不工作?我做错了什么?

Answer 1

在单元测试中，可能会发生类没有增强的情况，特别是当您在IDE中运行它们时。

确保增强的类包含在您在进行测试的项目中导入的不同模块中。

或者您可以运行增强过程，验证类已被增强，然后再运行单元测试。

总而言之，我猜您可能正在运行实体类的未增强版本。

无论如何，我不认为这个功能真的是必要的。同步关联的两端是可行的方法，它只需要您提供addChild和removeChild方法。

Answer 2

跟踪Andrei的JIRA问题，我了解到:

来触发关联管理，在某些情况下必须有* many字段的更改，即使它与相同的集合。不跟踪集合本身的更改。

所以，而不是:

customer.getInventories().add( customerInventory );

需要调用setter:

Collection<CustumerInventory> inventories = customer.getInventories();
inventories.add( customerInventory ); 
custumer.setInventories( inventories );