java - 如何使 spring data jpa 生成的方法在空参数上抛出异常

Question

我有这个服务方法，它调用一个由 spring 生成的 repo 方法:

服务方式:

 public User findUserByEmail(String email) {
        try {
            Assert.notNull(email,"email is null!");
            Optional<User> userOptional = userRepo.findUserDAOByEmail(email);
            return userOptional.orElseThrow();
        } 
        catch (...){
            ...
        }
    }

repo :

public interface UserRepo extends JpaRepository<User, Long> {
    Optional<User> findUserByEmail(String email);
}

我希望 repo 方法像它的 friend 一样抛出 IllegalArgumentException (使用 Jparepository 开箱即用的方法)，但它接受了 null 参数“email”并在数据库中搜索它，返回的结果是不存在这样的用户(p.s.:在我的模式中电子邮件被限制为不为空)

所以我做了Assert.notNull(email,"email is null!");

但我想知道是否有更好的方法来验证“email”不为空？

Answer 1

也可以像这样对参数施加约束 -

@Validated
@Repository
public interface UserRepo extends JpaRepository<User, Long> {
    Optional<User> findUserByEmail(@NotNull String email);
}

@Validated 使 Spring 能够调用各种验证约束。

工作示例

---

gradle依赖

    compile 'org.springframework.boot:spring-boot-starter'
    compile 'org.springframework.boot:spring-boot-starter-web'
    compile 'org.springframework.boot:spring-boot-starter-validation'
    compile 'org.springframework.boot:spring-boot-starter-data-jpa'
    compile("mysql:mysql-connector-java:8.0.16")

UserRepository.java

@Validated
@Repository
public interface UserRepository extends JpaRepository<User, Integer> {
    Optional<User> findUserByName(@NotEmpty String name);
}

控制台输出

javax.validation.ConstraintViolationException: findUserByName.name: must not be empty
    at org.springframework.validation.beanvalidation.MethodValidationInterceptor.invoke(MethodValidationInterceptor.java:117) ~[spring-context-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at com.sun.proxy.$Proxy88.findUserByName(Unknown Source) ~[na:na]
    at com.test.validation.controller.UserController.get(UserController.java:18) ~[main/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.2.RELEASE.jar:5.2.2.RELEASE]