Hibernate 的一對多自關聯
阿新 • • 發佈：2018-11-03
關於查詢許可權選單的載入一般有兩種方法：
1，直接查詢出全部的選單載入到瀏覽器頁面
2，類似於Hibernate中的懶載入，第一次載入一級節點與二級節點，
當點選二級節點再去後臺查詢三級節點用於瀏覽器的展示
- 實體類
package com.more.entity; import java.util.ArrayList; import java.util.List; public class TreeNode { private Integer TreeNodeId; //許可權id private String TreeNodeName; //許可權名 private Integer TreeNodeType; private Integer position; private Integer parentNodeId; //它的父許可權Id private String url; //一個兒子一個父親 private TreeNode treeNode; //一個父親多個兒子 private List<TreeNode> treeNodes=new ArrayList<>(); //強制載入 private Integer initTreeNode; public Integer getTreeNodeId() { return TreeNodeId; } public void setTreeNodeId(Integer treeNodeId) { TreeNodeId = treeNodeId; } public String getTreeNodeName() { return TreeNodeName; } public void setTreeNodeName(String treeNodeName) { TreeNodeName = treeNodeName; } public Integer getTreeNodeType() { return TreeNodeType; } public void setTreeNodeType(Integer treeNodeType) { TreeNodeType = treeNodeType; } public Integer getPosition() { return position; } public void setPosition(Integer position) { this.position = position; } public Integer getParentNodeId() { return parentNodeId; } public void setParentNodeId(Integer parentNodeId) { this.parentNodeId = parentNodeId; } public String getUrl() { return url; } public void setUrl(String url) { this.url = url; } public TreeNode getTreeNode() { return treeNode; } public void setTreeNode(TreeNode treeNode) { this.treeNode = treeNode; } public List<TreeNode> getTreeNodes() { return treeNodes; } public void setTreeNodes(List<TreeNode> treeNodes) { this.treeNodes = treeNodes; } public Integer getInitTreeNode() { return initTreeNode; } public void setInitTreeNode(Integer initTreeNode) { this.initTreeNode = initTreeNode; } @Override public String toString() { return "TreeNode [TreeNodeId=" + TreeNodeId + ", TreeNodeName=" + TreeNodeName + ", TreeNodeType=" + TreeNodeType + ", position=" + position + ", parentNodeId=" + parentNodeId + ", url=" + url + ", treeNodes=" + treeNodes + "]"; } }
- 實體類的對映檔案
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <!-- table: 資料庫表 name : 資料庫表對應的實體類的全限定名 --> <class name="com.more.entity.TreeNode" table="t_hibernate_sys_tree_node"> <id name="TreeNodeId" type="java.lang.Integer" column="tree_node_id"> <generator class="increment"></generator> </id> <property name="TreeNodeName" type="java.lang.String" column="tree_node_name"/> <property name="TreeNodeType" type="java.lang.Integer" column="tree_node_type"/> <property name="position" type="java.lang.Integer" column="position"/> <property name="parentNodeId" type="java.lang.Integer" column="parent_node_id"/> <property name="url" type="java.lang.String" column="url"/> <!-- 重複對映錯誤解決 insert="false" update="false" --> <many-to-one name="treeNode" class="com.more.entity.TreeNode" column="parent_node_id" insert="false" update="false"/> <bag order-by="position" name="treeNodes" cascade="save-update" inverse="true"> <!-- 配置外來鍵關鍵欄位 --> <key column="parent_node_id"/> <!-- 配置外來鍵關聯的表 --> <one-to-many class="com.more.entity.TreeNode"/> </bag> </class> </hibernate-mapping>
- 查詢方法
package com.more.dao; import org.hibernate.Hibernate; import org.hibernate.Session; import com.more.entity.TreeNode; import com.strurts.utli.HibernateUtils; public class TreeNodeDao { /** * 查詢節點 * @param treeNode * @return */ public TreeNode getTreeNode(TreeNode treeNode) { Session session = HibernateUtils.openSession(); TreeNode nd = session.get(TreeNode.class, treeNode.getTreeNodeId()); if(nd!=null&& new Integer(1).equals(treeNode.getInitTreeNode())) { Hibernate.initialize(nd.getTreeNodes()); } //呼叫提交事務，關閉session的方法 HibernateUtils.closesessionn(); return nd; } }
- 測試
public class TreeNodeDaoTest {
private TreeNodeDao dao=new TreeNodeDao();
@Test
public void testGetTreeNode() {
TreeNode treeNode=new TreeNode();
treeNode.setTreeNodeId(1); //節點Id
treeNode.setInitTreeNode(1); //設定立即載入
TreeNode nd = this.dao.getTreeNode(treeNode);
for(TreeNode n:nd.getTreeNodes()) {
System.out.println(n.getTreeNodeName());
}
System.out.println(nd);
}
}
- 結果
字典管理
使用者管理
角色管理
許可權管理
TreeNode [TreeNodeId=1, TreeNodeName=系統管理, TreeNodeType=1, position=1, parentNodeId=null, url=null, treeNodes=[TreeNode [TreeNodeId=3, TreeNodeName=字典管理, TreeNodeType=2, position=3, parentNodeId=1, url=null, treeNodes=[]], TreeNode [TreeNodeId=4, TreeNodeName=使用者管理, TreeNodeType=2, position=4, parentNodeId=1, url=null, treeNodes=[]], TreeNode [TreeNodeId=5, TreeNodeName=角色管理, TreeNodeType=2, position=5, parentNodeId=1, url=null, treeNodes=[]], TreeNode [TreeNodeId=6, TreeNodeName=許可權管理, TreeNodeType=1, position=6, parentNodeId=1, url=null, treeNodes=[TreeNode [TreeNodeId=10, TreeNodeName=使用者分配角色, TreeNodeType=2, position=10, parentNodeId=6, url=null, treeNodes=[]], TreeNode [TreeNodeId=11, TreeNodeName=角色授予使用者, TreeNodeType=2, position=11, parentNodeId=6, url=null, treeNodes=[]]]]]]
附： 資料庫表
-- 一對多雙向自關聯
-- 選單表
-- t_hibernate_sys_tree_node
-- t：表
-- sys：模組名縮寫(system)
-- tree_noe：表名
create table t_hibernate_sys_tree_node
(
tree_node_id int primary key auto_increment, -- ID
tree_node_name varchar(50) not null, -- 名字
tree_node_type int not null check(tree_node_type = 1 or tree_node_type = 2), -- 節點型別：1 枝節點 2 葉節點
position int, -- 位置
parent_node_id int, -- 父節點ID
url varchar(1024), -- URL
foreign key(parent_node_id) references t_hibernate_sys_tree_node(tree_node_id)
);
-- drop table t_hibernate_sys_tree_node
-- select * from t_hibernate_sys_tree_node
select * from t_hibernate_sys_tree_node;
truncate table t_hibernate_sys_tree_node;
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(1,'系統管理',1, 1,null,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(2,'市場管理',1, 2,null,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(3,'字典管理',2, 3,1,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(4,'使用者管理',2, 4,1,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(5,'角色管理',2, 5,1,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(6,'許可權管理',1, 6,1,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(7,'進貨管理',2, 7,2,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(8,'銷售管理',2, 8,2,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(9,'庫存管理',2, 9,2,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(10,'使用者分配角色',2, 10,6,null);
insert into t_hibernate_sys_tree_node(tree_node_id, tree_node_name, tree_node_type, position, parent_node_id, url)
values(11,'角色授予使用者',2, 11,6,null);