JSR303自定义validation器被调用两次

我正在使用Spring MVC创建一个网站，并且为了持久性我使用Spring Data JPA和Hibernate 4作为我的JPA提供者。 目前正在使用Hibernate Validator处理validation。 我有一个问题，我的validation器被调用两次，我无法弄清楚为什么。 这是一个问题的主要原因是因为第二轮，依赖关系没有自动连接到validation器，我得到一个空指针exception。 以下是导致失败的呼叫序列：

1. 提交注册表单，首先调用NotDefaultSectValidator并成功完成用户对象上的“whereDidYouHearAboutUs”字段。
2. 接下来调用UniqueUsernameValidator并成功完成“用户名”字段validation。
3. 控制器上的’addUserFromForm’方法启动，并在bindingResults对象中找不到任何错误。
4. 然后在UserService类上调用’addUser’方法。 此方法到达’userRepository.save（user）;’行 但之后不要立即运行’print.ln’行。 单步执行此行将返回到“NotDefaultSectValidator”断点。 这是第二次完成，我重新输入第二个validation器’UniqueUsernameValidator’。 这里我得到一个空指针exception，因为出于某种原因，Spring第二次无法在DAO中自动assembly。

任何人都可以阐明为什么validation器被调用两次，特别是为什么要跨越’userRepository.save（user）;’ 回到这些validation器？

非常感谢

这是我的user.java类

package com.dating.domain; import java.util.HashSet; import java.util.Set; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.PrePersist; import javax.persistence.PreUpdate; import javax.persistence.Table; import javax.persistence.Transient; import javax.validation.constraints.Pattern; import javax.validation.constraints.Size; import org.hibernate.annotations.Type; import org.hibernate.validator.constraints.Email; import org.hibernate.validator.constraints.NotEmpty; import org.joda.time.LocalDate; import org.springframework.format.annotation.DateTimeFormat; import com.dating.annotation.NotDefaultSelect; import com.dating.annotation.UniqueUsername; @Entity @Table(name = "dating.user") public class User { @Id @Column(name = "id") @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(name = "username", unique = true) @NotEmpty @Pattern(regexp = "^[a-zA-Z0-9]*$") @UniqueUsername private String username; @Column(name = "password", nullable = false) @NotEmpty @Size(min = 8) private String password; @Column(name = "first_name", nullable = false) @NotEmpty private String firstName; @Column(name = "last_name", nullable = false) @NotEmpty private String lastName; @Transient private String fullName; @Column(name = "email", nullable = false) @NotEmpty @Email private String email; @Column(name = "gender", nullable = false) @NotEmpty private String gender; @Column(name = "date_of_birth", nullable = false) @Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDate") @DateTimeFormat(pattern = "dd/MM/yyyy") private LocalDate dateOfBirth; @Column(name = "join_date", nullable = false) @Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDate") private LocalDate joinDate; @Column(name = "where_did_you_hear_about_us", nullable = false) @NotDefaultSelect private String whereDidYouHearAboutUs; @Column(name = "enabled") private boolean enabled; @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL) @JoinTable(name = "dating.user_roles", joinColumns = { @JoinColumn(name = "user_id", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "role_id", nullable = false, updatable = false) }) private Set roles = new HashSet(); @Column(name = "created_time", nullable = false) @Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDate") private LocalDate createdTime; @Column(name = "modification_time", nullable = false) @Type(type = "org.jadira.usertype.dateandtime.joda.PersistentLocalDate") private LocalDate modificationTime; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public String getFullName() { return firstName + " " + lastName; } public void setFullName(String fullName) { this.fullName = fullName; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } public String getGender() { return gender; } public void setGender(String gender) { this.gender = gender; } public LocalDate getDateOfBirth() { return dateOfBirth; } public void setDateOfBirth(LocalDate dateOfBirth) { this.dateOfBirth = dateOfBirth; } public LocalDate getJoinDate() { return joinDate; } public void setJoinDate(LocalDate joinDate) { this.joinDate = joinDate; } public String getWhereDidYouHearAboutUs() { return whereDidYouHearAboutUs; } public void setWhereDidYouHearAboutUs(String whereDidYouHearAboutUs) { this.whereDidYouHearAboutUs = whereDidYouHearAboutUs; } public boolean isEnabled() { return enabled; } public void setEnabled(boolean enabled) { this.enabled = enabled; } public Set getRoles() { return roles; } public void setRoles(Set roles) { this.roles = roles; } public void addRole(Role role) { roles.add(role); } public LocalDate getCreatedTime() { return createdTime; } public void setCreatedTime(LocalDate createdTime) { this.createdTime = createdTime; } public LocalDate getModificationTime() { return modificationTime; } public void setModificationTime(LocalDate modificationTime) { this.modificationTime = modificationTime; } @PreUpdate public void preUpdate() { modificationTime = new LocalDate(); } @PrePersist public void prePersist() { LocalDate now = new LocalDate(); createdTime = now; modificationTime = now; } } 

我的注册控制器中的相关方法：

 @RequestMapping(value = "/register", method = RequestMethod.POST) public String addUserFromForm(@Valid User user, BindingResult bindingResult, RedirectAttributes ra) { if (bindingResult.hasErrors()) { return "user/register"; } userService.addUser(user); // Redirecting to avoid duplicate submission of the form return "redirect:/user/" + user.getUsername(); } 

我的服务类：

 package com.dating.service.impl; import javax.transaction.Transactional; import org.joda.time.LocalDate; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder; import org.springframework.stereotype.Service; import com.dating.domain.Role; import com.dating.domain.User; import com.dating.repository.RoleRepository; import com.dating.repository.UserRepository; import com.dating.repository.specification.UserSpecifications; import com.dating.service.UserService; @Service public class UserServiceImpl implements UserService { @Autowired private UserRepository userRepository; @Autowired private RoleRepository roleRepository; @Transactional @Override public void addUser(User user) { user.setJoinDate(new LocalDate()); user.setEnabled(true); Role role = roleRepository.findByName(Role.MEMBER); if (role == null) { role = new Role(); role.setName(Role.MEMBER); } user.addRole(role); BCryptPasswordEncoder encoder = new BCryptPasswordEncoder(); user.setPassword(encoder.encode(user.getPassword())); userRepository.save(user); System.out.println("User Saved"); } @Override public User getUserByUsername(String username) { return userRepository.findByUsername(username); } @Override public Iterable getAllUsers() { return userRepository.findAll(); } @Override public void updateDetails(User user) { userRepository.save(user); } @Override public Iterable lastNameIsLike(String searchTerm) { return userRepository.findAll(UserSpecifications .lastNameIsLike(searchTerm)); } } 

我的NotDefaultSelectvalidation器：

 package com.dating.validator; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import com.dating.annotation.NotDefaultSelect; public class NotDefaultSelectValidator implements ConstraintValidator { @Override public void initialize(NotDefaultSelect constraint) { } @Override public boolean isValid(String selectedValue, ConstraintValidatorContext ctx) { if (selectedValue == null) { return false; } if (selectedValue.equals("") || selectedValue.equals("0") || selectedValue.equalsIgnoreCase("default") || selectedValue.equalsIgnoreCase("please select")) { return false; } return true; } } 

我的uniqueUsernamevalidation器：

 package com.dating.validator; import javax.validation.ConstraintValidator; import javax.validation.ConstraintValidatorContext; import org.springframework.beans.factory.annotation.Autowired; import com.dating.annotation.UniqueUsername; import com.dating.repository.UserRepository; public class UniqueUsernameValidator implements ConstraintValidator { @Autowired private UserRepository userRepository; @Override public void initialize(UniqueUsername constraint) { } @Override public boolean isValid(String username, ConstraintValidatorContext ctx) { if (username == null || userRepository.findByUsername(username) == null) { return true; } return false; } } 

我的UserRepository：

 package com.dating.repository; import org.springframework.data.jpa.repository.JpaSpecificationExecutor; import org.springframework.data.repository.CrudRepository; import com.dating.domain.User; //Spring Data JPA Marker interfaces being extended for automatic CRUD repository creation public interface UserRepository extends CrudRepository, JpaSpecificationExecutor { //Automatic query creation from method name public User findByUsername(String username); } 

最后是我的persistence-context.xml文件

                           #{dataSourceSettings['hibernate.dialect']} #{dataSourceSettings['hibernate.hbm2ddl.auto']}  #{dataSourceSettings['hibernate.show_sql']} #{dataSourceSettings['hibernate.format_sql']} #{dataSourceSettings['hibernate.use_sql_comments']}           

Answer 1

当你将bean发送到数据存储区时，也许第二次validation是由hibernate完成的。 要关闭它，请将其添加到persistence.xml：

https://docs.jboss.org/hibernate/entitymanager/3.5/reference/en/html/configuration.html说：

默认情况下，Bean Validation（和Hibernate Validator）已激活。 创建，更新（并可选地删除）实体时，会在发送到数据库之前对其进行validation。 Hibernate生成的数据库模式也反映了在实体上声明的约束。

如果需要，您可以对其进行微调：

AUTO：如果类路径中存在Beanvalidation，则激活CALLBACK和DDL。

CALLBACK：在创建，更新和删除时validation实体。 如果不存在Bean Validation提供程序，则会在初始化时引发exception。

DDL :(不是标准，见下文）数据库模式是在创建，更新和删除时validation实体。 如果不存在Bean Validation提供程序，则会在初始化时引发exception。

NONE：根本不使用Beanvalidation

第一个显然是由Spring控制器完成的，因为@Valid注释。