Hibernate註解實現單表遞歸樹形結構

目錄：

1. 概述
2. 環境
3. 代碼示例
4. 測試結果

[一]、概述

在系統中，常常會用到無限級遞歸的樹形結構，好比菜單、組織機構管理、多級分類等等，通常是在同一個表中定義父子關係實現這種樹形結構，本文主要講述如何運用hibernate全註解的方式實現這個功能。

[二]、環境

• hibernate 4.1.2
• java 1.6
• mysql 5.1

[三]、代碼示例

第一步：建立Entity類，並添加註解實現關聯關係

ps: 主要是利用@ManyToOne 和 @OneToMany 配置在同一個Entity類中實現樹形遞歸的結構。

TreeNode.java

1	package com.micmiu.hibernate.anno.entity;

2

3	import java.util.LinkedHashSet;

4	import java.util.Set;

5

6	import javax.persistence.CascadeType;

7	import javax.persistence.Column;

8	import javax.persistence.Entity;

9	import javax.persistence.FetchType;

10	import javax.persistence.GeneratedValue;

11	import javax.persistence.Id;

12	import javax.persistence.JoinColumn;

13	import javax.persistence.ManyToOne;

14	import javax.persistence.OneToMany;

15	import javax.persistence.Table;

16

17

/**

18

* 樹形結構示例

19

*

20	* @author <a href="http://www.micmiu.com">Michael Sun</a>

21

*/

22

@Entity

23	@Table(name = "DEMO_T_TREE_NODE")

24	public class TreeNode {

25

26	public TreeNode() {

27

}

28

29	public TreeNode(String name) {

30	this.name = name;

31

}

32

33	private int id;

34

35	private String name;

36

// 父節點

37	private TreeNode parent;

38

// 子節點

39	private Set<TreeNode> children = new LinkedHashSet<TreeNode>();

40

41

@Id

42	@Column(name = "ID")

43	@GeneratedValue

44	public int getId() {

45	return id;

46

}

47

48	@Column(name = "NAME", length = 20)

49	public String getName() {

50	return name;

51

}

52

53	@ManyToOne(cascade = CascadeType.ALL, fetch = FetchType.EAGER)

54	@JoinColumn(name = "PARENT_ID")

55	public TreeNode getParent() {

56	return parent;

57

}

58

59	@OneToMany(cascade = CascadeType.ALL, mappedBy = "parent", fetch = FetchType.EAGER)

60	public Set<TreeNode> getChildren() {

61	return children;

62

}

63

64	public void setId(int id) {

65	this.id = id;

66

}

67

68	public void setName(String name) {

69	this.name = name;

70

}

71

72	public void setParent(TreeNode parent) {

73	this.parent = parent;

74

}

75

76	public void setChildren(Set<TreeNode> children) {

77	this.children = children;

78

}

79

}

第二步：建立hibernate默認配置文件：

hibernate.cfg.xml

1	<?xml version='1.0' encoding='UTF-8'?>

2	<!DOCTYPE hibernate-configuration PUBLIC

3	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"

4	"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

5

6	<hibernate-configuration>

7

8	<session-factory>

9

10	<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

11	<property name="connection.driver_class">com.mysql.jdbc.Driver</property>

12	<property name="connection.url">jdbc:mysql://localhost:3306/michaeldemo</property>

13	<property name="connection.username">root</property>

14	<property name="connection.password"></property>

15

16	<property name="show_sql">true</property>

17	<property name="format_sql">true</property>

18

19	<property name="current_session_context_class">thread</property>

20	<property name="hbm2ddl.auto">update</property>

21

22	<mapping class="com.micmiu.hibernate.anno.entity.TreeNode" />

23	</session-factory>

24

25	</hibernate-configuration>

第三步：建立測試文件：

HibernateAnnoTreeTest.java

1	package com.micmiu.hibernate;

2

3	import org.hibernate.Session;

4	import org.hibernate.SessionFactory;

5	import org.hibernate.cfg.Configuration;

6	import org.hibernate.service.ServiceRegistry;

7	import org.hibernate.service.ServiceRegistryBuilder;

8	import org.junit.AfterClass;

9	import org.junit.BeforeClass;

10	import org.junit.Test;

11

12	import com.micmiu.hibernate.anno.entity.TreeNode;

13

14

/**

15

* 測試

16

*

17	* @author <a href="http://www.micmiu.com">Michael Sun</a>

18

*/

19	public class HibernateAnnoTreeTest {

20

21	private static SessionFactory sessionFactory;

22

23	@BeforeClass

24	public static void beforeClass() {

25	Configuration configuration = new Configuration().configure();

26	ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()

27	.applySettings(configuration.getProperties())

28	.buildServiceRegistry();

29	sessionFactory = configuration.buildSessionFactory(serviceRegistry);

30

31

}

32

33	@AfterClass

34	public static void afterClass() {

35	sessionFactory.close();

36

}

37

38

@Test

39	public void testTreeCRUD() {

40	// 先運行添加測試

41	// testSave();

42

43

// 讀取測試

44	// testRead();

45

46

// 更新測試

47	testUpdate();

48

49

// 刪除測試

50	// testDelete();

51

}

52

53	public void testSave() {

54	System.out.println("========>測試添加 start <========");

55	Session session = sessionFactory.openSession();

56

57	session.beginTransaction();

58	TreeNode rootNode = initData();

59	session.save(rootNode);

60	session.getTransaction().commit();

61	session.close();

62	System.out.println("========>測試添加 end <========");

63	// 讀取添加的數據

64	testRead();

65

}

66

67	public void testRead() {

68	System.out.println("========>讀取 start <========");

69	Session session = sessionFactory.openSession();

70	session.beginTransaction();

71	System.out.println("-----> get root node:");

72	TreeNode rootNode = (TreeNode) session.get(TreeNode.class, 1);

73

74	System.out.println("-----> 輸出樹形結構以下:");

75	printNode(rootNode, 0);

76

77	session.getTransaction().commit();

78	session.close();

79	System.out.println("========>讀取 end <========");

80

}

81

82	public void testUpdate() {

83	// 更新前讀取信息

84	testRead();

85	System.out.println("========>測試更新 start <========");

86	Session session = sessionFactory.openSession();

87	session.beginTransaction();

88

89	System.out.println("---> 更新節點屬性");

90	TreeNode rootNode = (TreeNode) session.get(TreeNode.class, 1);

91	System.out.println("get root node:" + rootNode.getName()

92	+ " child size:" + rootNode.getChildren().size());

93	rootNode.setName(rootNode.getName() + "(個人blog)");

94

95	TreeNode node_del = null;

96	for (TreeNode node : rootNode.getChildren()) {

97	if ("Hazel".equals(node.getName())) {

98	node_del = node;

99

}

100

}

101	System.out.println("---> 刪除節點(包含子節點)");

102	System.out.println("delete node:" + node_del.getName() + " child size:"

103	+ node_del.getChildren().size());

104	node_del.setParent(null);

105	rootNode.getChildren().remove(node_del);

106	session.delete(node_del);

107

108	System.out.println("---> 添加節點(包含子節點)");

109	TreeNode node_add = new TreeNode("企業應用");

110	node_add.setParent(rootNode);

111	rootNode.getChildren().add(node_add);

112

113	TreeNode node_add_0 = new TreeNode("SNMP");

114	node_add_0.setParent(node_add);

115	node_add.getChildren().add(node_add_0);

116

117	TreeNode node_add_1 = new TreeNode("SSO");

118	node_add_1.setParent(node_add);

119	node_add.getChildren().add(node_add_1);

120

121	session.update(rootNode);

122

123	System.out.println("---> 節點下添加子節點");

124	TreeNode node_update = (TreeNode) session.get(TreeNode.class, 6);

125	TreeNode node_child_add = new TreeNode("go(新增)");

126	System.out.println("append child node:" + node_child_add.getName()

127	+ " to parent node: " + node_update.getName());

128	node_child_add.setParent(node_update);

129	node_update.getChildren().add(node_child_add);

130

131	System.out.println("---> 節點下刪除子節點");

132

133	TreeNode node_child_del = node_update.getChildren().iterator().next();

134	System.out.println("delete node child :" + node_child_del.getName()

135	+ " from parent node: " + node_update.getName());

136	node_update.getChildren().remove(node_child_del);

137	node_child_del.setParent(null);

138	session.delete(node_child_del);

139

140	session.update(node_update);

141

142	session.getTransaction().commit();

143	session.close();

144	System.out.println("========>測試更新 end <========");

145	// 更新後讀取信息

146	testRead();

147

}

148

149	public void testDelete() {

150	// 刪除前讀取信息

151	testRead();

152	System.out.println("========>測試刪除 start <========");

153	Session session = sessionFactory.openSession();

154	session.beginTransaction();

155	TreeNode node = (TreeNode) session.get(TreeNode.class, 6);

156	System.out.println("node:" + node.getName() + " child size:"

157	+ node.getChildren().size());

158	TreeNode childNode = node.getChildren().iterator().next();

159	childNode.setParent(null);

160	node.getChildren().remove(childNode);

161	session.delete(childNode);

162	System.out.println("delete node:" + childNode.getName()

163	+ " from parent:" + node.getName());

164

165	session.update(node);

166	session.getTransaction().commit();

167	session.close();

168	System.out.println("========>測試刪除 end <========");

169	// 刪除後讀取信息

170	testRead();

171

172

}

173

174

/**

175

* 模擬測試數據

176

*/

177	private TreeNode initData() {

178	TreeNode rootNode = new TreeNode("micmiu.com");

179

180

// 一級

181	TreeNode node0 = new TreeNode("Michael");

182	node0.setParent(rootNode);

183	rootNode.getChildren().add(node0);

184

185

// 二級

186	TreeNode node0_0 = new TreeNode("J2EE");

187	node0_0.setParent(node0);

188	node0.getChildren().add(node0_0);

189

// 二級

190	TreeNode node0_1 = new TreeNode("SOA");

191	node0_1.setParent(node0);

192	node0.getChildren().add(node0_1);

193

// 二級

194	TreeNode node0_2 = new TreeNode("NoSQL");

195	node0_2.setParent(node0);

196	node0.getChildren().add(node0_2);

197

198

// 二級

199	TreeNode node0_3 = new TreeNode("編程語言");

200	node0_3.setParent(node0);

201	node0.getChildren().add(node0_3);

202

203

// 三級

204	TreeNode node0_3_0 = new TreeNode("Java");

205	node0_3_0.setParent(node0_3);

206	node0_3.getChildren().add(node0_3_0);

207

208	TreeNode node0_3_1 = new TreeNode("Groovy");

209	node0_3_1.setParent(node0_3);

210	node0_3.getChildren().add(node0_3_1);

211

212	TreeNode node0_3_2 = new TreeNode("javascript");

213	node0_3_2.setParent(node0_3);

214	node0_3.getChildren().add(node0_3_2);

215

216

// 一級

217	TreeNode node1 = new TreeNode("Hazel");

218	node1.setParent(rootNode);

219	rootNode.getChildren().add(node1);

220

// 二級

221	TreeNode node1_0 = new TreeNode("life");

222	node1_0.setParent(node1);

223	node1.getChildren().add(node1_0);

224

// 二級

225	TreeNode node1_1 = new TreeNode("美食");

226	node1_1.setParent(node1);

227	node1.getChildren().add(node1_1);

228

// 二級

229	TreeNode node1_2 = new TreeNode("旅遊");

230	node1_2.setParent(node1);

231	node1.getChildren().add(node1_2);

232

233	return rootNode;

234

}

235

236	private void printNode(TreeNode node, int level) {

237	String preStr = "";

238	for (int i = 0; i < level; i++) {

239	preStr += "|----";

240

}

241	System.out.println(preStr + node.getName());

242	for (TreeNode children : node.getChildren()) {

243	printNode(children, level + 1);

244

}

245

}

246

247

}

第四步：建立日誌輸出配置文件：

log4j.properties

1	# Output pattern : date [thread] priority category - message

2	log4j.rootLogger=info, Console

3

4

#Console

5	log4j.appender.Console=org.apache.log4j.ConsoleAppender

6	log4j.appender.Console.layout=org.apache.log4j.PatternLayout

7	log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n

8

9	log4j.logger.org.hibernate.tool.hbm2ddl=debug

10	log4j.logger.org.hibernate.test=info

[四]、測試結果

測試添加方法，輸出日誌以下：

========>測試添加 start <========
========>測試添加 end <========
========>讀取 start <========
-----> get root node:
-----> 輸出樹形結構以下:
micmiu.com
|----Michael
|----|----J2EE
|----|----SOA
|----|----NoSQL
|----|----編程語言
|----|----|----Java
|----|----|----Groovy
|----|----|----javascript
|----Hazel
|----|----life
|----|----美食
|----|----旅遊
========>讀取 end <========

數據庫中查詢記錄以下:

再運行測試程序中的更新方法，輸出日誌以下：

========>讀取 start <========
-----> get root node:
-----> 輸出樹形結構以下:
micmiu.com
|----Michael
|----|----J2EE
|----|----SOA
|----|----NoSQL
|----|----編程語言
|----|----|----Java
|----|----|----Groovy
|----|----|----javascript
|----Hazel
|----|----life
|----|----美食
|----|----旅遊
========>讀取 end <========
========>測試更新 start <========
---> 更新節點屬性
get root node:micmiu.com child size:2
---> 刪除節點(包含子節點)
delete node:Hazel child size:3
---> 添加節點(包含子節點)
---> 節點下添加子節點
append child node:go(新增) to parent node: 編程語言
---> 節點下刪除子節點
delete node child :Java from parent node: 編程語言
========>測試更新 end <========
========>讀取 start <========
-----> get root node:
-----> 輸出樹形結構以下:
micmiu.com(個人blog)
|----Michael
|----|----J2EE
|----|----SOA
|----|----NoSQL
|----|----編程語言
|----|----|----Groovy
|----|----|----javascript
|----|----|----go(新增)
|----企業應用
|----|----SNMP
|----|----SSO
========>讀取 end <========

數據庫中查詢記錄以下:

本文介紹到此結束