spring rest中的

Question

@ExceptionHandler(ConstraintViolationException.class)
@ResponseStatus(HttpStatus.BAD_REQUEST)
public @ResponseBody
ExceptionResponseDTO hiberAnnotationExceptionHandler(ConstraintViolationException exception) {
    return  new ExceptionResponseDTO("Entity is null or we are out of range!", exception.getMessage(), ExceptionMapper.INSTANCE.exceptionToExceptionDTO(exception));
}

@Entity
public class Device {

    @Id
    @Column(name="name", nullable = false)
    private String Name;

    @Column(name = "send_date")
    @NotNull
    private Date sendDate;
}

Device d = new Device();
d.setName("sdsdsd");
d.setSendDate(null);
deviceRepository.save(d);

结果，我收到下一个异常：

[dispatcherServlet]:？-servlet.service（）对于servlet[dispatcherServlet]在路径[]的上下文中抛出异常[请求处理失败；嵌套异常是org.springframework.transaction.transactionsystemException：无法提交JPA事务；嵌套异常是javax.persistence.rollbackException：提交事务时出错]具有根原因javax.Validation.ConstraintViolationException：在组[javax.Validation.groups.default]的更新期间对类[com.entity.device]的验证失败Validation.constraints.notnull.message}‘}]

因此，您可以从stacktrace中看到，我首先接收TransactionSystemException，因此，我的ExceptionHandler方法（hiberAnnotationExceptionHandler）不调用。所以我的问题是如何模拟这个异常（ConstraintViolationException）？提前谢了。

Answer 1

TransactionSystemException的原因

1. hibernate实体管理器负责抛出所有hibernate异常

如果进入代码AbstractEntityManagerImpl.convert（）方法，您将看到默认情况下它不处理任何特定的异常，如ConstraintViolution，而是在PersistenceException中抛出和包装。

1. 首先注册一个JPA方言，它可以截获这些HibernateException，并在事务管理器bean中封装成特定的spring异常，就像这样。

 <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory"/>
    <property name="jpaDialect" ref="jpaDialect"/>
</bean>

<bean id="jpaDialect" class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>

HibernateJpaDealion捕获这些异常，并将其转换为spring特定的异常，如下所示

if (ex instanceof ConstraintViolationException) {
          ConstraintViolationException jdbcEx = (ConstraintViolationException) ex;
          return new DataIntegrityViolationException(ex.getMessage()  + "; SQL [" + jdbcEx.getSQL() +
                  "]; constraint [" + jdbcEx.getConstraintName() + "]", ex);
      }

<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
      <property name="packagesToScan" value="com.pack.model" />
        <property name="persistenceUnitManager" ref="persistenceUnitManager"/>
        <property name="persistenceUnitName" value="entityManager"/>
        <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/>
    </bean>    <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>

@ExceptionHandler(dataIntegrityViolationException.class)