hibernate 一對多自關聯查詢（如選單表）
阿新 • • 發佈：2018-10-31
hibernate 有自帶的選單查詢功能，當查詢的節點有幾千條時，hibernate自帶的選單查詢會造成卡頓的情況，但一般情況下hibernate自帶的選單查詢減少程式設計師的程式碼量，
簡化了程式碼
相關測試資料（MySQL）
-- 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); );
配置選單表的對映檔案
<?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> <class name="com.zking.entity.TreeNode" table="t_hibernate_sys_tree_node"> <id name="treeNode_id" type="java.lang.Integer" column="tree_node_id"> <generator class="increment" /> </id> <property name="treeNode_name" type="java.lang.String" column="tree_node_name"></property> <property name="treeNode_type" type="java.lang.Integer" column="tree_node_type"></property> <property name="position" type="java.lang.Integer" column="position"></property> <property name="url" type="java.lang.String" column="url"></property> <many-to-one name="treeNode" class="com.zking.entity.TreeNode" column="parent_node_id"></many-to-one> <!-- <set name="treeNodes" cascade="save-update" inverse="true" > <key column="parent_node_id"></key> <one-to-many class="com.zking.entity.TreeNode"/> </set> --> <!-- list 集合配置也有list標籤，小編比較喜歡用當前這個 order-by：填的表的列段，按照所填的列段排列 --> <bag order-by="position" name="treeNodes" cascade="save-update" inverse="true" > <key column="parent_node_id"></key> <one-to-many class="com.zking.entity.TreeNode"/> </bag> </class> </hibernate-mapping>
選單實體類
package com.zking.entity; import java.io.Serializable; import java.util.ArrayList; import java.util.List; public class TreeNode implements Serializable { /** * 2018年10月25日下午6:30:23 */ private static final long serialVersionUID = -5329689980623631639L; private Integer treeNode_id; private String treeNode_name; private Integer treeNode_type; private Integer position; private String url; //父節點 private TreeNode treeNode; //載入許可權是無序的 // private Set<TreeNode> treeNodes = new HashSet<>(); //載入許可權是有序的 //子節點 private List<TreeNode> treeNodes = new ArrayList<>(); private Integer initTreeNode; @Override public String toString() { return "TreeNode [treeNode_id="+ treeNode_id +",treeNode_name="+ treeNode_name +",treeNode_type="+ treeNode_type +",position="+ position +",url="+ url +",treeNode="+ treeNode +",treeNodes="+ treeNodes +",initTreeNode="+ initTreeNode +"]"; } public Integer getTreeNode_id() { return treeNode_id; } public void setTreeNode_id(Integer treeNode_id) { this.treeNode_id = treeNode_id; } public String getTreeNode_name() { return treeNode_name; } public void setTreeNode_name(String treeNode_name) { this.treeNode_name = treeNode_name; } public Integer getTreeNode_type() { return treeNode_type; } public void setTreeNode_type(Integer treeNode_type) { this.treeNode_type = treeNode_type; } public Integer getPosition() { return position; } public void setPosition(Integer position) { this.position = position; } 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 Set<TreeNode> getTreeNodes() { // return treeNodes; // } // // public void setTreeNodes(Set<TreeNode> treeNodes) { // this.treeNodes = treeNodes; // // } public Integer getInitTreeNode() { return initTreeNode; } public List<TreeNode> getTreeNodes() { return treeNodes; } public void setTreeNodes(List<TreeNode> treeNodes) { this.treeNodes = treeNodes; } public void setInitTreeNode(Integer initTreeNode) { this.initTreeNode = initTreeNode; } public TreeNode() { super(); } public TreeNode(Integer treeNode_id, String treeNode_name, Integer treeNode_type, Integer position, String url, TreeNode treeNode, List<TreeNode> treeNodes, Integer initTreeNode) { super(); this.treeNode_id = treeNode_id; this.treeNode_name = treeNode_name; this.treeNode_type = treeNode_type; this.position = position; this.url = url; this.treeNode = treeNode; this.treeNodes = treeNodes; this.initTreeNode = initTreeNode; } }
選單表許可權查詢
package com.zking.dao.daoImpl;
import java.util.List;
import org.hibernate.Hibernate;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.zking.entity.TreeNode;
import com.zking.util.HibernateUtli;
public class TreeNodeDaoImpl implements ITreeNodeDaoImpl {
@Override
public TreeNode getTreeNode(TreeNode treeNode) {
Session session = HibernateUtli.getCurrentSession();
Transaction transaction = session.beginTransaction();
TreeNode t = null;
try {
t = session.get(TreeNode.class, treeNode.getTreeNode_id());
if (null != t && new Integer(1).equals(treeNode.getInitTreeNode())) {
Hibernate.initialize(t.getTreeNodes());
}
transaction.commit();
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();
throw new RuntimeException("查詢出現異常");
}
HibernateUtli.closeSession();
return t;
}
測試
package com.zking.test;
import org.junit.Before;
import org.junit.Test;
import com.zking.dao.daoImpl.TreeNodeDaoImpl;
import com.zking.entity.TreeNode;
public class TreeNodeDaoTest {
private TreeNodeDaoImpl daoImpl = null;
private TreeNode node = null;
@Before
public void setUp() throws Exception {
daoImpl = new TreeNodeDaoImpl();
node = new TreeNode();
}
@Test
public void testget() {
this.node.setTreeNode_id(1);
this.node.setInitTreeNode(1);
TreeNode treeNode = this.daoImpl.getTreeNode(this.node);
System.out.println(treeNode.getTreeNode_name());
for (TreeNode s : treeNode.getTreeNodes()) {
System.out.println(s.getTreeNode_id() + "," + s.getTreeNode_name());
}
/*
* 第二種許可權載入方案
* 類似於hibernate的懶載入
* 第一載入一級節點和二級節點
* 當點選二級節點再去向獲取後臺用於展示
*/
}
}