我正在使用 Spring MVC 创建一个网站，为了持久性，我使用 Spring Data JPA 和 Hibernate 4 作为我的 JPA 提供程序。目前正在使用 Hibernate Validator 处理验证。我遇到一个问题，我的验证器被调用两次，但我不明白为什么。这是一个问题的主要原因是因为第二次，依赖项没有被自动连接到验证器中，并且我收到了空指针异常。
以下是导致失败的调用顺序：
- 提交注册表单后，首先调用 NotDefaultSectValidator，并针对用户对象上的“whereDidYouHearAboutUs”字段成功完成。
- 接下来调用 UniqueUsernameValidator 并成功完成“用户名”字段验证。
- 控制器上的 'addUserFromForm' 方法启动，并在 bindingResults 对象中发现没有错误。
- 然后在 UserService 类上调用“addUser”方法。此方法到达“userRepository.save(user);”行但之后绝不会立即运行“print.ln”行。越过此行需要返回到“NotDefaultSectValidator”断点。这是第二次完成，我重新输入第二个验证器“UniqueUsernameValidator”。这里我得到一个空指针异常，因为由于某种原因 Spring 第二次未能在 DAO 中自动装配。
任何人都可以阐明为什么验证器被调用两次，特别是为什么要跨行“userRepository.save(user);”回到这些验证器？
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<Role> roles = new HashSet<Role>();
@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<Role> getRoles() {
return roles;
}
public void setRoles(Set<Role> 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();
}
我的服务等级：
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<User> getAllUsers() {
return userRepository.findAll();
}
@Override
public void updateDetails(User user) {
userRepository.save(user);
}
@Override
public Iterable<User> lastNameIsLike(String searchTerm) {
return userRepository.findAll(UserSpecifications
.lastNameIsLike(searchTerm));
}
}
我的 NotDefaultSelect 验证器：
package com.dating.validator;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import com.dating.annotation.NotDefaultSelect;
public class NotDefaultSelectValidator implements
ConstraintValidator<NotDefaultSelect, String> {
@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;
}
}
我的唯一用户名验证器：
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<UniqueUsername, String> {
@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;
}
}
我的用户存储库：
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<User, Long>, JpaSpecificationExecutor<User> {
//Automatic query creation from method name
public User findByUsername(String username);
}
最后是我的 persistence-context.xml 文件
<!-- Data source properties -->
<util:properties id="dataSourceSettings" location="classpath:datasource.properties" />
<!-- Pooled data source using BoneCP -->
<bean id="dataSource" class="com.jolbox.bonecp.BoneCPDataSource"
destroy-method="close">
<property name="driverClass" value="#{dataSourceSettings['jdbc.driverClass']}" />
<property name="jdbcUrl" value="#{dataSourceSettings['jdbc.url']}" />
<property name="username" value="#{dataSourceSettings['jdbc.username']}" />
<property name="password" value="#{dataSourceSettings['jdbc.password']}" />
<property name="idleConnectionTestPeriodInMinutes" value="60" />
<property name="idleMaxAgeInMinutes" value="240" />
<property name="maxConnectionsPerPartition" value="30" />
<property name="minConnectionsPerPartition" value="10" />
<property name="partitionCount" value="3" />
<property name="acquireIncrement" value="5" />
<property name="statementsCacheSize" value="100" />
<property name="releaseHelperThreads" value="3" />
</bean>
<!-- JPA entity manager factory bean -->
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="com.dating.domain" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.dialect">#{dataSourceSettings['hibernate.dialect']}</prop>
<prop key="hibernate.hbm2ddl.auto">#{dataSourceSettings['hibernate.hbm2ddl.auto']}
</prop>
<prop key="hibernate.show_sql">#{dataSourceSettings['hibernate.show_sql']}</prop>
<prop key="hibernate.format_sql">#{dataSourceSettings['hibernate.format_sql']}</prop>
<prop key="hibernate.use_sql_comments">#{dataSourceSettings['hibernate.use_sql_comments']}
</prop>
</props>
</property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<context:annotation-config />
<jpa:repositories base-package="com.dating.repository"/>
