Spring Boot ConstraintViolationException 适用于创建但不适用于更新答案

【问题标题】：Spring Boot ConstraintViolationException works on create but not on updateSpring Boot ConstraintViolationException 适用于创建但不适用于更新
【发布时间】：2019-08-01 06:18:44
【问题描述】：

我在 Spring Boot 中有一个模型，对字段有正则表达式约束

@Entity(name = "foo")
public class Foo {

     //primary key id and other fields

     @Pattern(regexp="^[0-9]{10}", message="length must be 10")  
     @Column(name = "mobile_number", nullable = false)
     private String mobileNumber;

}

我还有一个异常处理程序

 @Order(Ordered.HIGHEST_PRECEDENCE)
 @ControllerAdvice
 public class RestExceptionHandler extends ResponseEntityExceptionHandler {

    // other exception handlers

    @ExceptionHandler(javax.validation.ConstraintViolationException.class)
    protected ResponseEntity<Object> handleConstraintViolation(javax.validation.ConstraintViolationException ex) {
        ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST);
        apiError.setMessage("Validation Error");
        apiError.addValidationErrors(ex.getConstraintViolations());
        return buildResponseEntity(apiError);
    }
}

现在，当我使用不正确的手机号码模式创建 Foo 的新实例时，ConstraintViolationException 被抛出，我收到消息 Validation Error。但是，当我尝试使用不正确的手机号码更新 Foo 的现有实例时，不会触发此异常。相反，我收到以下错误：

11:28:30.357 [http-nio-8080-exec-6] ERROR o.a.c.c.C.[.[.[.[dispatcherServlet] - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.transaction.TransactionSystemException: Could not commit JPA transaction; nested exception is javax.persistence.RollbackException: Error while committing the transaction] with root cause
javax.validation.ConstraintViolationException: Validation failed for classes [com.example.app.model.Foo] during update time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='length must be 10', propertyPath=mobileNumber, rootBeanClass=class com.example.app.model.Foo, messageTemplate='length must be 10'}
]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:140)
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreUpdate(BeanValidationEventListener.java:88)
    at org.hibernate.action.internal.EntityUpdateAction.preUpdate(EntityUpdateAction.java:248)
    at org.hibernate.action.internal.EntityUpdateAction.execute(EntityUpdateAction.java:119)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:604)
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:478)
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:356)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1454)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:511)
    at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3283)
    at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2479)
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473)

为什么它在创建时起作用但在更新时不起作用？我们是否需要添加一些配置来检查约束违规以进行更新？另外，如何让消息“长度必须为 10”而不是“验证错误”显示？我似乎无法通过handleConstraintViolation 方法访问@Pattern 中定义的消息。

【问题讨论】：

标签： java spring-boot exception constraints

【解决方案1】：

尝试在进入方法前添加@Valid注解，只有注解过的实体字段，持久化后才生效。

@Valid 在进入方法之前验证对象。

【讨论】：

【解决方案2】：

为参数添加@Valid注释，为类添加@Validated。
对于打印，一条消息将此异常句柄添加到@ContollerAdvice

@ExceptionHandler(MethodArgumentTypeMismatchException.class)
        @ResponseStatus(HttpStatus.BAD_REQUEST)
        public String handleException(MethodArgumentTypeMismatchException exception) {
            return exception.getName() + " should be of type " + exception.getRequiredType().getName();
        }

【讨论】：