Question

我正在使用Hibernate 4.3.0.Final（JPA 2.1）和MySQL 5.5。我想将我的Java枚举映射到具有相应值的MySQL表。所以我的枚举是

public enum Roles
{
    STUDENT("Student"),
    TEACHER("Teacher"),
    …

    Roles(final String name)
    {
        this.name = name;
    }

    private final String name;

    @Override
    public String toString()
    {
        return getName();
    }

    public String getName()
    {
        return this.name;
    }
}

我的表包含

之类的值

+------------------------+------------------------+-------------+
| ID                     | NAME                   | ADMIN_LEVEL |
+------------------------+------------------------+-------------+
| Student                | Student                |           1 |
| Teacher                | Teacher                |          10 |

然后，在代表上表的实体类中，我有

@GenericGenerator(name = "uuid-strategy", strategy = "org.mainco.subco.core.util.subcoUUIDGenerator")
@Entity(name = "sb_role")
public class Role implements Serializable, Comparable<Role>
{

    @Id
    @NotNull
    @GeneratedValue(generator = "uuid-strategy")
    @Column(name = "ID")
    /* the database id of the role */
    private String id;

    @Enumerated(value=EnumType.STRING)
    @Column(name = "NAME")
    /* the String name of the role */
    private Roles name;

然而，当我运行我的应用程序时，我收到如下错误。如何在枚举值和数据库中的列之间强制执行完整性？

java.lang.IllegalArgumentException: Parameter value [Student] did not match expected type [org.mainco.subco.user.domain.Roles (n/a)]
    at org.hibernate.jpa.spi.BaseQueryImpl.validateBinding(BaseQueryImpl.java:885)
    at org.hibernate.jpa.internal.QueryImpl.access$000(QueryImpl.java:80)
    at org.hibernate.jpa.internal.QueryImpl$ParameterRegistrationImpl.bindValue(QueryImpl.java:248)
    at org.hibernate.jpa.spi.BaseQueryImpl.setParameter(BaseQueryImpl.java:631)
    at org.hibernate.jpa.spi.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:179)
    at org.hibernate.jpa.spi.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:49)
    at org.hibernate.jpa.criteria.compile.CriteriaCompiler$1$1.bind(CriteriaCompiler.java:126)
    at org.hibernate.jpa.criteria.CriteriaQueryImpl$1.buildCompiledQuery(CriteriaQueryImpl.java:386)
    at org.hibernate.jpa.criteria.compile.CriteriaCompiler.compile(CriteriaCompiler.java:147)
    at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:736)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:241)
    at com.sun.proxy.$Proxy71.createQuery(Unknown Source)
    at org.mainco.subco.core.repo.AbstractHibernateDAO.findByUniqueConstraint(AbstractHibernateDAO.java:104)
    at org.mainco.subco.user.repo.RoleDaoImpl.findRoleByName(RoleDaoImpl.java:26)
    at org.mainco.subco.user.service.RoleServiceImpl.findByName(RoleServiceImpl.java:43)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:96)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:260)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:94)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
    at com.sun.proxy.$Proxy91.findByName(Unknown Source)
    at org.mainco.subco.resource.service.ResourceServiceIT.testFindById(ResourceServiceIT.java:95)

我对写一个@Converter不感兴趣（有很多值要考虑），除非这是绝对最简单的解决方案。

Answer 1

@Enumerated（值= EnumType.STRING）

使用ENUM的值学生教师

不是括号中的那个，在数据库中，您有以小写字母开头的值在数据库中进行更新以使其大写该列中的所有值，这是最简单的解决方案，它应该工作，并且不会影响数据完整性。 XD。

使用JPA / Hibernate，如何将Java枚举映射到MySQL表中的列？

1 个答案: