Hibernate验证器：Nosuchmethodexception

Question

我正在为练习做一个reddit克隆，并为唯一用户名添加了自定义验证。 我一直都会得到此例外（当用户名是唯一的，并且在不是时也是如此）：

2022-05-03 16:08:21.466 ERROR 11516 --- [nio-8080-exec-5] 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

java.lang.NoSuchMethodException: com.reddit.validation.UniqueUsernameValidator.<init>()
    at java.base/java.lang.Class.getConstructor0(Class.java:3349) ~[na:na]
    at java.base/java.lang.Class.getConstructor(Class.java:2151) ~[na:na]
    at org.hibernate.validator.internal.util.privilegedactions.NewInstance.run(NewInstance.java:41) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorFactoryImpl.run(ConstraintValidatorFactoryImpl.java:43) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorFactoryImpl.getInstance(ConstraintValidatorFactoryImpl.java:28) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ClassBasedValidatorDescriptor.newInstance(ClassBasedValidatorDescriptor.java:84) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.AbstractConstraintValidatorManagerImpl.createAndInitializeValidator(AbstractConstraintValidatorManagerImpl.java:89) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintValidatorManagerImpl.getInitializedValidator(ConstraintValidatorManagerImpl.java:117) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.getInitializedConstraintValidator(ConstraintTree.java:136) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.SimpleConstraintTree.validateConstraints(SimpleConstraintTree.java:54) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.constraintvalidation.ConstraintTree.validateConstraints(ConstraintTree.java:75) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.doValidateConstraint(MetaConstraint.java:130) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.metadata.core.MetaConstraint.validateConstraint(MetaConstraint.java:123) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateMetaConstraint(ValidatorImpl.java:555) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForSingleDefaultGroupElement(ValidatorImpl.java:518) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForDefaultGroup(ValidatorImpl.java:488) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateConstraintsForCurrentGroup(ValidatorImpl.java:450) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validateInContext(ValidatorImpl.java:400) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.validator.internal.engine.ValidatorImpl.validate(ValidatorImpl.java:172) ~[hibernate-validator-6.2.3.Final.jar:6.2.3.Final]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:116) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreInsert(BeanValidationEventListener.java:80) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.action.internal.EntityInsertAction.preInsert(EntityInsertAction.java:214) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:100) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:604) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.engine.spi.ActionQueue.lambda$executeActions$1(ActionQueue.java:478) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:684) ~[na:na]
    at org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:475) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:344) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:40) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.event.service.internal.EventListenerGroupImpl.fireEventOnEachListener(EventListenerGroupImpl.java:107) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1407) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:489) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3290) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2425) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:449) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:183) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:40) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:281) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:101) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:562) ~[spring-orm-5.3.18.jar:5.3.18]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:743) ~[spring-tx-5.3.18.jar:5.3.18]
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:711) ~[spring-tx-5.3.18.jar:5.3.18]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:654) ~[spring-tx-5.3.18.jar:5.3.18]
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:407) ~[spring-tx-5.3.18.jar:5.3.18]
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.18.jar:5.3.18]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.18.jar:5.3.18]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.18.jar:5.3.18]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:698) ~[spring-aop-5.3.18.jar:5.3.18]
    at com.reddit.service.UserDetailServiceImpl$$EnhancerBySpringCGLIB$$9f92bba9.saveUser(<generated>) ~[classes/:na]
    at com.reddit.controller.MainController.signupForm(MainController.java:51) ~[classes/: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:205) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:681) ~[tomcat-embed-core-9.0.60.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.60.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:327) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:115) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:81) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:122) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:116) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:126) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:81) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:109) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:149) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:219) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:213) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:103) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:89) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.header.HeaderWriterFilter.doHeadersAfter(HeaderWriterFilter.java:90) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:75) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:110) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:80) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:55) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:336) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:211) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:183) ~[spring-security-web-5.6.2.jar:5.6.2]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:354) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:267) ~[spring-web-5.3.18.jar:5.3.18]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:889) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1743) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

instrulyusername

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Constraint(validatedBy = UniqueUsernameValidator.class)
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.FIELD)
public @interface UniqueUsername {
    String message() default "There is already a user with this username.";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

userveImpositor

import com.reddit.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

@Component
public class UniqueUsernameValidator implements ConstraintValidator<UniqueUsername, String> {

    private final UserService userService;

    @Autowired
    public UniqueUsernameValidator(UserService userService) {
        this.userService = userService;
    }

    @Override
    public void initialize(UniqueUsername constraintAnnotation) {

    }

    @Override
    public boolean isValid(String value, ConstraintValidatorContext constraintValidatorContext) {
        return userService.isUsernameAlreadyInUse(value);
    }
}

问题是当我运行该应用程序并尝试注册时，

import javax.persistence.*;
import javax.validation.constraints.Email;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.Size;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

@Entity
@Table(name = "users")
public class User {

    @Id
    @GeneratedValue
    private Long id;
    private String firstName;
    private String lastName;
    @NotEmpty
    @Size(min = 10)
    //@UniqueEmail
    private String email;
    @NotEmpty
    @Size(min = 3, max = 16, message = "is required")
    @UniqueUsername
    private String username;
    @NotEmpty
    @Size(min = 6, max = 100)
    private String password;
    private String country;
    private Date registrationDate = new Date();
    private boolean enabled = false;

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "user", orphanRemoval = true)
    private List<Post> posts = new ArrayList<>();

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "user", orphanRemoval = true)
    private List<Comment> comments = new ArrayList<>();

    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    private List<Subreddit> subreddits = new ArrayList<>();

    public User() {
    }

    public User(String firstName, String lastName, String email, String username, String password, String country, boolean enabled) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.email = email;
        this.username = username;
        this.password = password;
        this.country = country;
        this.enabled = enabled;
    }

    // setters & getters
}

userviceimpositor

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Lazy;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.Collection;
import java.util.Collections;
import java.util.Optional;

@Service
public class UserDetailServiceImpl implements UserService {

    private final UserRepository userRepository;
    private final PasswordEncoder passwordEncoder;

    @Autowired
    public UserDetailServiceImpl(UserRepository userRepository, @Lazy PasswordEncoder passwordEncoder) {
        this.userRepository = userRepository;
        this.passwordEncoder = passwordEncoder;
    }

    // . . .

    @Transactional
    public boolean isUsernameAlreadyInUse(String username) {
        return userRepository.existsUserByUsername(username);
    }
}

我

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import java.util.Optional;

@Repository
public interface UserRepository extends CrudRepository<User, Long> {

    Optional<User> findUserByUsername(String username);
    boolean existsUserByUsername(String username);
    boolean existsUserByEmail(String email);
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com</groupId>
    <artifactId>reddit</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>redditclone</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.thymeleaf.extras</groupId>
            <artifactId>thymeleaf-extras-springsecurity5</artifactId>
        </dependency>
        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.19.1</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

尝试过的其他类似

1. 帖子 到验证器类，
2. 使用现场注入
3. @component使用localValidatorFactoryBean
4. 添加一个空构造函数添加了一个空构造函数
5. ，添加了验证 - api依赖关系，
6. 添加了Javaee-api依赖关系，

但没有一个解决问题。

任何帮助都将不胜感激，因为我现在已经持续了两天了。