我正在使用spring 3和hibernate 4开发Web应用程序。 我无法延迟加载用户所属组的一组授权权限。 从数据库中检索用户对象时,即使显式调用user.getGroup()。getPermissions(),其Group对象也没有任何权限。
我注意到在调试模式下,如果我将鼠标悬停在User对象上,然后导航到User对象内的Group对象,然后导航到其权限,我可以看到它的类型显示为PersistentSet,并展开它将正确加载权限。但在非调试模式下,权限永远不会延迟加载。我在这里错过了什么?提前谢谢。
以下是实体之间的关系: 用户与组之间存在一对多关系,并且组与权限之间存在多对多关系。
这是UserDaoImpl类的定义
@Repository
@Transactional
public class UserDaoImpl implements UserDao {
@Autowired
private SessionFactory sessionFactory;
private Session getSession() {
return sessionFactory.getCurrentSession();
}
@Override
public User get(String username) {
Session session = getSession();
User user = (User) session.createCriteria(User.class).add(Restrictions.eq("username", username)).uniqueResult();
Group g = user.getGroup();
// calling g.getGrantedPermissions() doesn't load any permission
Set<Permission> permissions = g.getGrantedPermissions();
return user;
}
}
以下是Permission类的定义
@Entity
public class Permission {
@Id
@GeneratedValue
private Long id;
@Column
private String name;
@Column
private String description;
public Permission()
{
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
这是Group类的定义
@Entity
@Table(name="\"Group\"")
public class Group {
public static final String ROLE_VALID_USER = "ROLE_VALID_USER";
@Id
@GeneratedValue
private Long id;
@Column
private String description;
@Column
private String role;
@ManyToMany
@JoinTable(name = "granted_permission",
joinColumns = {@JoinColumn(name = "GROUP_ID", nullable = false, updatable = false) },
inverseJoinColumns = { @JoinColumn(name = "PERMISSION_ID", nullable = false, updatable = false) })
private Set<Permission> grantedPermissions;
public Group()
{
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
public Set<Permission> getGrantedPermissions() {
return grantedPermissions;
}
public void setGrantedPermissions(Set<Permission> grantedPermissions) {
this.grantedPermissions = grantedPermissions;
}
}
以下是User类的定义
@Entity
public class User {
@Id
@Column(name="USERNAME")
private String username;
@Column(name="PASSWORD")
private String password;
@Transient
private final boolean enabled = true;
@Column
private String name;
@Column(name="EMAIL")
private String email;
@Column(name="PHONE")
private String phone;
@ManyToOne
private Group group;
@ManyToOne
@JoinColumn(name="ORIGINAL_BRANCH_ID")
private Branch originalBranch;
@ManyToOne
@JoinColumn(name="ID_OF_RESPONSIBLE_BRANCH")
private Branch responsibleBranch;
public User()
{
}
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 getRole() {
return group.getRole();
}
public boolean isEnabled() {
return enabled;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
public Group getGroup() {
return group;
}
public void setGroup(Group group) {
this.group = group;
}
public Branch getOriginalBranch() {
return originalBranch;
}
public void setOriginalBranch(Branch originalBranch) {
this.originalBranch = originalBranch;
}
public Branch getResponsibleBranch() {
return responsibleBranch;
}
public void setResponsibleBranch(Branch responsibleBranch) {
this.responsibleBranch = responsibleBranch;
}
}
这是持久性配置:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<tx:annotation-driven />
<context:annotation-config />
<bean id="transactionManager"
class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
<context:component-scan base-package="net.acme.prs" />
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="dataSource" ref="mysqlDataSource" />
<property name="packagesToScan" value="net.acme.prs" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQL5InnoDBDialect
</prop>
<prop key="hibernate.show_sql">false</prop>
</props>
</property>
</bean>
<bean id="mysqlDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/prs" />
<property name="username" value="" />
<property name="password" value="" />
</bean>
</beans>
答案 0 :(得分:3)
我无法理解您的问题是什么,因为您没有提到您遇到的任何错误。如果您只是发现没有SQL来获取grantedPermissions
,那么它就是延迟获取的内容:它仅在访问时获取,如果未访问它,则不会获取它。 / p>
您在调试期间看到它被提取的原因是因为当您在调试器中检查grantedPermissions
时,它正在访问该属性,这将触发延迟提取。但是,对于非调试模式,如果没有访问该属性的代码,则不会提取它应该执行的操作。
如果您要问的是,您的代码处于非调试模式,将访问grantedPermissions
但是在访问时延迟获取失败,那么这是由于访问超出事务:Hibernate需要有一个活动的Session来进行延迟抓取。如果延迟提取发生在事务之外,它将失败,因为没有打开的Session。您应该考虑
答案 1 :(得分:0)
关注http://docs.oracle.com/javaee/5/api/javax/persistence/FetchType.html
示例:如果要在“组”中自动加载“grantedPermissions”,则必须将注释更改为@ManyToMany(fetch = FetchType.EAGER)