hibernate中联合主键的使用

在java后台权限设置时需要使用联合主键来唯一标识权限

public class SystemPrivilegePK implements Serializable{


	private static final long serialVersionUID = 1L;

	private SystemPrivilegePK id;
	private String model;
	private String privilege;
	public SystemPrivilegePK(){}
	public SystemPrivilegePK(String module, String privilege2) {
		
	    this.model = module;
	    this.privilege = privilege2;
	}
	
	get和set方法省略
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((model == null) ? 0 : model.hashCode());
		result = prime * result + ((privilege == null) ? 0 : privilege.hashCode());
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		SystemPrivilegePK other = (SystemPrivilegePK) obj;
		if (model == null) {
			if (other.model != null)
				return false;
		} else if (!model.equals(other.model))
			return false;
		if (privilege == null) {
			if (other.privilege != null)
				return false;
		} else if (!privilege.equals(other.privilege))
			return false;
		return true;
	}
	@Override
	public String toString() {
		return "SystemPrivilegePK [model=" + model + ", privilege=" + privilege + "]";
	}

}

xml配置为:

<class name="com.robin.main.privilege.systemprivilege.SystemPrivilegePK" table="SYSTEMPRIVILEGEPK">
        <composite-id name="id" class="com.robin.main.privilege.systemprivilege.SystemPrivilegePK">
            <key-property name="model" column="model" type="string"></key-property>
            <key-property name="privilege" column="privilege" type="string"></key-property>
            
        </composite-id>
</class>

public class SystemPrivilege {
	
	private SystemPrivilegePK id;
	private String name;
	private Set<PrivilegeGroup> pgs = new HashSet<>();
	
	public SystemPrivilege(){}
	
	public SystemPrivilege(String module, String privilege, String name) {
		this.id = new SystemPrivilegePK(module, privilege);
		this.name = name;
	}
	
	
	public SystemPrivilege(SystemPrivilegePK id) {
		this.id = id;
	}
	

	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((id == null) ? 0 : id.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		SystemPrivilege other = (SystemPrivilege) obj;
		if (id == null) {
			if (other.id != null)
				return false;
		} else if (!id.equals(other.id))
			return false;
		return true;
	}

	@Override
	public String toString() {
		return "SystemPrivilege [id=" + id + ", name=" + name + "]";
	}
}
其中关于外键id的XML配置:
<composite-id name="id" class="com.robin.main.privilege.systemprivilege.SystemPrivilegePK">
           <key-property name="model" column="model" type="string"></key-property>
           <key-property name="privilege" column="privilege" type="string"></key-property>
</composite-id>
<set name="pgs" table="t_sp_pg">
            <key>
               <column name="model"></column>
               <column name="privilege"></column>
            </key>
            
            <many-to-many class="com.robin.main.privilege.systemprivilege.PrivilegeGroup" column="pgs_id"></many-to-many>
</set>

public class PrivilegeGroup {
	
	private Integer groupid;
	private String name;
	private Set<SystemPrivilege> sps = new HashSet<>();
	private Set<Employee> employees = new HashSet<>();
	
        public PrivilegeGroup(){}
	
	public PrivilegeGroup(Integer groupid) {
		this.groupid = groupid;
	}
	

	public void addSystemPrivilege(SystemPrivilege privilege){
		this.sps.add(privilege);
	}

}

xml配置为:

<id name="groupid" type="java.lang.Integer">
            <column name="GROUPID" />
            <generator class="native" />
</id>

<set name="sps" table="t_sp_pg">
            <key column="pgs_id"></key>
            <many-to-many class="com.robin.main.privilege.systemprivilege.SystemPrivilege">
               <column name="model"></column>
               <column name="privilege"></column>
            </many-to-many>
</set>

SystemPrivilege由SystemPrivilegePK作为它的主键，

SystemPrivilegePK需要实现序列化接口，并且需要实现相应的equals和hashcode方法来比较对象是否相等