[英]Hibernate deletes Lazy loaded many-to-many collection when a get call is made on the collection
我试图在java应用程序中使用hibernate从数据库中获取角色。 我正在进行多对多的映射。
获取数据后,它将从数据库中删除。 我没有调用删除方法仍然发生删除。
Role.java
@Entity
@Table(name = "ROLE")
public class Role extends BaseModel implements java.io.Serializable {
private Long id;
private Set<User> users = new HashSet<User>(0);
@Id
@Column(name = "ID", unique = true, nullable = false, scale = 0)
public Long getId() {
return this.id;
}
public void setId(Long id) {
this.id = id;
}
@ManyToMany(fetch = FetchType.LAZY, mappedBy = "roles")
@JoinTable(name = "USERROLEMAP", joinColumns = { @JoinColumn(name = "ROLEID", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "USERID", nullable = false, updatable = false) })
public Set<User> getUsers() {
return this.users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
}
User.java
@Cacheable
@Entity
@Table(name = "USER", uniqueConstraints = @UniqueConstraint(columnNames = "LOGINID"))
public class User extends BaseModel implements java.io.Serializable {
private Long id;
private Set<Role> roles = new HashSet<Role>(0);
@Id
@Column(name = "ID", unique = true, nullable = false, scale = 0)
public Long getId() {
return this.id;
}
public void setId(Long id) {
this.id = id;
}
@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "USERROLEMAP", joinColumns = { @JoinColumn(name = "USERID", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "ROLEID", nullable = false, updatable = false) })
public Set<Role> getRoles() {
return this.roles;
}
}
我们正在尝试使用以下代码片段从数据库中获取角色
public List<String> rolesAsGA() {
List<String> proxyUserRoles = new ArrayList<String>();
Iterator<Role> itr = getRoles().iterator();
while (itr.hasNext()) {
proxyUserRoles.add(new SimpleGrantedAuthority(itr.next()
.getRoleName()));
}
return proxyUserRoles;
}
获取角色后,数据(相应的角色)会被同时删除,任何人都可以告诉我为什么?
编辑 -我们在eclipse中进行调试,而hibernate正在标记要删除的集合,因为currentPersistor对于集合实体变为null。 将进一步调试并发布任何更新。
编辑1我们错过了提到,用户是@Cacheable,并且是从ehcache获取的,当正在进行getRole调用时,集合被加载,然后提示排队等待删除。 删除@Cacheable注释可以解决问题。 我是否创建了关于@Cacheable和manytomany的单独问题,还是我只是更新这个问题并希望找到合适的解决方案?
我想这是一个问题
private Set<Role> roles = new HashSet<Role>(0);
@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "USERROLEMAP", joinColumns = { @JoinColumn(name = "USERID", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "ROLEID", nullable = false, updatable = false) })
public Set<Role> getRoles() {
return this.roles;
}
它应该是
private Set<Role> roles;
@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "USERROLEMAP", joinColumns = { @JoinColumn(name = "USERID", nullable = false, updatable = false) }, inverseJoinColumns = { @JoinColumn(name = "ROLEID", nullable = false, updatable = false) })
public Set<Role> getRoles() {
if(roles == null){
return new HashSet<Role>;
}
return this.roles;
}
因为每当调用getRoles时,它总是返回一个空集。 所以hibernate假设您实际上已经清空/删除了该集并在数据库中删除它们
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