Hibernate删除，添加问题

当单向多对多，单向一对多，删除其中没有维护的一方的数据时，因为没有级联关系，需要手动取消关联关系，然后才能删除，不然因为外键报错

BUser-单向多对多->Role

BUser

package com.cpic.shz.entity;
 
import java.util.Arrays;
import java.util.Date;
import java.util.Set;
 
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
import javax.persistence.Transient;
 
import org.apache.commons.lang3.builder.ToStringBuilder;
 
import com.cpic.shz.util.DataUtil;
import com.google.common.collect.Sets;
 
/**
 * @package :　 com.cpic.shz.entity
 * @file : BUser.java
 * @date : 2015年9月17日 上午10:47:25
 * @user : liuhao
 * @note : 后台角色表
 */
@Entity
@Table
public class BUser{
 
private static final long serialVersionUID = 1L;
private Integer id;
 
private Set<Role> roles = Sets.newHashSet();
 
public BUser() {
}
@Id
@GeneratedValue
public Integer getId() {
return id;
}
 
public void setId(Integer id) {
this.id = id;
}
 
@ManyToMany
@JoinTable(name = "shz_hc_buser_role", 
joinColumns = { @JoinColumn(name = "buser_id") }, 
inverseJoinColumns = { @JoinColumn(name = "role_id") })
public Set<Role> getRoles() {
return roles;
}
public void setRoles(Set<Role> roles) {
this.roles = roles;
}
}

Role

package com.cpic.shz.entity;
 
import java.util.HashSet;
import java.util.Set;
 
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;
 
import org.apache.commons.lang3.builder.ToStringBuilder;
 
@Entity
@Table
public class Role {
 
private static final long serialVersionUID = 1L;
 
private Integer id;
private Set<Right> rights = new HashSet<Right>();
@Id
@GeneratedValue
public Integer getId() {
return id;
}
 
public void setId(Integer id) {
this.id = id;
}
}

当删除一个role时，因为buser_role表中外键连接两个buser_id，role_id，role又没有级联关系，所以报错

手动取消buser_role表中带有当前role_id的行

再删除role

deleteRole方法

public String deleteRole() {
try {
buserService.updateBUserByRoleId(model.getId());
roleService.deleteEntity(model);
root.put("msg", "删除id=" + model.getId() + "成功!");
} catch (Exception e) {
root.put("msg", "删除id=" + model.getId() + "失败!");
e.printStackTrace();
}
return "json";
}

updateBUserByRoleId取消buser_role表中带有role_id的行

1. 多对多查询 select a from A a left join a.b where b.id = ?

2. 遍历busers中存在role_id的buser，将其移除

3. 保存新的buser

@SuppressWarnings("unchecked")
@Rollback(value=true)
@Override
public void updateBUserByRoleId(Integer id) {
StringBuffer hql = new StringBuffer();
hql.append("select buser from BUser buser left join buser.roles r ");
hql.append(" where r.id = ? ");
 
List<BUser> busers = findEntityByHQL(hql.toString(), id);
if(ObjectUtil.isNotEmpty(busers))
for (BUser buser : busers) {
Set<Role> roles = buser.getRoles();
List<Role> lroles = (List<Role>) ObjectUtil.changeSetToList(roles);
for (Role role : lroles) {
if (role.getId() == id)
roles.remove(role);
}
buser.setRoles(roles);
updateEntity(buser);
}
}

添加问题

eg：一对多添加数据不能在页面中直接buser.role.id，buser.role.name添加

只能将role_id一起传到后台，然后获取Integer[] role_id;的Role 对象

Set<Role> sets = buser.getRoles()

sets.add(role...);

buser.setRoles(sets);

saveOrUpdateEntity(buser);

public String saveOrUpdateRole() {
try {
List<Right> rights = rightService.findRightInRange(rightsId);
roleService.saveOrUpdateRole(model, rights);
root.put("msg", "操作" + model.getRoleName() + "成功!");
} catch (Exception e) {
root.put("msg", "操作" + model.getRoleName() + "失败!");
e.printStackTrace();
}
return "json";
}

查询所有的rightIds

@Override
public List<Right> findRightInRange(Integer[] rightsId) {
String hql = "from Right r where r.id in("+StringUtil.arr2Str(rightsId)+")";
return findEntityByHQL(hql);
}

设置添加Model

@Override
public void saveOrUpdateRole(Role model, List<Right> rights) {
if(model!=null){
HashSet<Right> setrights = (HashSet<Right>) model.getRights();
for(Right r:rights){
setrights.add(r);
}
model.setRights(setrights);
saveOrUpdateEntity(model);
}
}