1.注解方式：
注解的方式与xml很很多类似：
首先是需要在pom文件中加入4个jar包：
1 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 2 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> 3 <modelVersion>4.0.0</modelVersion> 4 <groupId>cn.yunhe</groupId> 5 <artifactId>hibernate3</artifactId> 6 <packaging>war</packaging> 7 <version>1.0-SNAPSHOT</version> 8 <name>hibernate3 Maven Webapp</name> 9 <url>http://maven.apache.org</url> 10 <dependencies> 11 <dependency> 12 <groupId>junit</groupId> 13 <artifactId>junit</artifactId> 14 <version>4.12</version> 15 <scope>test</scope> 16 </dependency> 17 18 <dependency> 19 <groupId>javax.servlet</groupId> 20 <artifactId>javax.servlet-api</artifactId> 21 <version>3.1.0</version> 22 <scope>provided</scope> 23 </dependency> 24 25 <dependency> 26 <groupId>mysql</groupId> 27 <artifactId>mysql-connector-java</artifactId> 28 <version>5.1.6</version> 29 </dependency> 30 31 <dependency> 32 <groupId>org.apache.struts</groupId> 33 <artifactId>struts2-core</artifactId> 34 <version>2.3.31</version> 35 </dependency> 36 37 <dependency> 38 <groupId>javax.servlet</groupId> 39 <artifactId>jstl</artifactId> 40 <version>1.2</version> 41 </dependency> 42 43 <dependency> 44 <groupId>org.apache.struts</groupId> 45 <artifactId>struts2-dojo-plugin</artifactId> 46 <version>2.3.16</version> 47 </dependency> 48 49 50 <!--以下四个包，缺一不可--> 51 <dependency> 52 <groupId>org.hibernate</groupId> 53 <artifactId>hibernate-core</artifactId> 54 <version>3.5.0-Final</version> 55 </dependency> 56 57 <dependency> 58 <groupId>org.hibernate</groupId> 59 <artifactId>hibernate-annotations</artifactId> 60 <version>3.5.0-Final</version> 61 </dependency> 62 63 <dependency> 64 <groupId>org.slf4j</groupId> 65 <artifactId>slf4j-log4j12</artifactId> 66 <version>1.5.8</version> 67 </dependency> 68 69 <dependency> 70 <groupId>org.javassist</groupId> 71 <artifactId>javassist</artifactId> 72 <version>3.13.0-GA</version> 73 </dependency> 74 </dependencies> 75 <build> 76 <finalName>hibernate3</finalName> 77 <plugins> 78 <plugin> 79 <groupId>org.eclipse.jetty</groupId> 80 <artifactId>jetty-maven-plugin</artifactId> 81 <version>9.3.14.v20161028</version> 82 </plugin> 83 </plugins> 84 </build> 85 </project>
pom.xml
下面是不同的地方：
（1）：hibernate.hbm.xml 文件中把引用：xxx.hbm.xml改为引用实体类：
即把：<mapping resource="com/wsw/hibernate/model/Person.hbm.xml"/>
改为：<mapping class="com.wsw.hibernate.model.Teacher" />
（2）：获取SessionFactory方式发生了变化：
即：由SessionFactory sf = new Configuration().configure().buildSessionFactory()
改为：SessionFactory sf = new AnnotationConfiguration().configure().buildSessionFactory()
（3）：注解方式不需要在xxx.hbm.xml把实体类与表进行映射。而采用在实体类中进行注解。
注意：
（1）：如果实体类属性名与表字段名不一致的时候，要么都注解在属性前，要么都注解在get方法前。不能部分注解在属性前，部分注解在方法前。
（2）：如果实体类属性名与表字段名一致的时候，可以部分注解在属性前，部分注解在方法前。
（3）：如果在实体类中某些属性不注解：（属性和get都不写注解），默认为表字段名与实体类属性名一致。
（4）：如果实体类的某个成员属性不需要存入数据库中，使用@Transient 进行注解就可以了。即类似于：(xxx.hbm.Xml配置中的某些字段不写(就是不需要对这个成员属性进行映射))
（5）：表名称可以在实体类前进行注解。
（6）：所有这些注解在：javax.persistence包下。而不是在hibernate包中。
2.单向一对多、单向多对一、双向多对一
1.实体类配置
1 package cn.yunhe.entity;
2
3 import javax.persistence.*;
4 import java.io.Serializable;
5
6
7 @Entity
8 @Table(name = "jd")
9 public class Jd {//街道
10 private int jdid;
11 private String jdname;
12 private Qx qx;//区县
13
14 @Id
15 @GeneratedValue
16 @Column(name = "jdid")
17 public int getJdid() {
18 return jdid;
19 }
20
21 public void setJdid(int jdid) {
22 this.jdid = jdid;
23 }
24
25 @Column(name = "jdname")
26 public String getJdname() {
27 return jdname;
28 }
29
30 public void setJdname(String jdname) {
31 this.jdname = jdname;
32 }
33
34 @ManyToOne(cascade = CascadeType.ALL,fetch = FetchType.LAZY)
35 @JoinColumn(name = "qxid")
36 public Qx getQx() {
37 return qx;
38 }
39
40 public void setQx(Qx qx) {
41 this.qx = qx;
42 }
43 }
Jd(街道)
1 package cn.yunhe.entity;
2
3 import javax.persistence.*;
4 import java.util.HashSet;
5 import java.util.Set;
6
7 @Entity
8 @Table(name = "qx")//实体类映射表
9 public class Qx {//区县
10 private int qxid;
11 private String qxname;
12 private Set<Jd> jds=new HashSet<Jd>();
13
14 @Id
15 @GeneratedValue
16 @Column(name = "qxid")
17 public int getQxid() {
18 return qxid;
19 }
20
21 public void setQxid(int qxid) {
22 this.qxid = qxid;
23 }
24
25 @Column(name = "qxname")
26 public String getQxname() {
27 return qxname;
28 }
29
30 public void setQxname(String qxname) {
31 this.qxname = qxname;
32 }
33
34 //@OneToMany(cascade = CascadeType.ALL,fetch = FetchType.LAZY ,mappedBy = "qx")//mappedBy里面写的是对象
35 //@JoinColumn(name ="qxid" ) 双向操作Qx一对多声明可以不需要@JoinColumn，但@OneToMany(...mappedBy="category")
36 public Set<Jd> getJds() {
37 return jds;
38 }
39
40 public void setJds(Set<Jd> jds) {
41 this.jds = jds;
42 }
43 }
Qx(区县)
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE hibernate-configuration 3 PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 4 "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 5 <hibernate-configuration> 6 <session-factory> 7 <property name="hibernate.hbm2ddl.auto" >update</property><!--自动生成数据库表--> 8 <property name="dialect">org.hibernate.dialect.MySQLDialect</property><!--数据库方言--> 9 <property name="connection.driver_class">com.mysql.jdbc.Driver</property> 10 <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property> 11 <property name="connection.username">root</property> 12 <property name="connection.password">1234</property> 13 <property name="show_sql">true</property><!--显示sql--> 14 15 <mapping class="cn.yunhe.entity.Qx"/> 16 <mapping class="cn.yunhe.entity.Jd"/> 17 </session-factory> 18 </hibernate-configuration>
hibernate.cfg.xml
2. 测试类
1 import cn.yunhe.entity.Jd;
2 import cn.yunhe.entity.Qx;
3 import org.hibernate.Session;
4 import org.hibernate.SessionFactory;
5 import org.hibernate.Transaction;
6 import org.hibernate.cfg.AnnotationConfiguration;
7 import org.hibernate.cfg.Configuration;
8 import org.junit.After;
9 import org.junit.Before;
10 import org.junit.Test;
11
12 import java.util.List;
13 import java.util.Set;
14
15 /**
16 * Created by Administrator on 2017/7/6.
17 */
18 public class Demo {
19 Session session=null;
20 Transaction tr=null;
21
22 @Before
23 public void setUp(){
24 Configuration config=new AnnotationConfiguration().configure();
25 SessionFactory factory= config.buildSessionFactory();
26 session=factory.openSession();
27 tr=session.beginTransaction();
28 }
29 @Test
30 public void testQuery(){
31 List<Qx> list = session.createQuery("from Qx").list();
32 for (Qx qx : list) {
33 System.out.println(qx.getQxname());
34 }
35 }
36
37 @Test
38 //单向一对多（使用时注意只能在实体类一的一方建多的一方对象，不能两边都创建）
39 public void testOneToMany(){
40 Qx qx= (Qx) session.get(Qx.class,1);
41 System.out.println(qx.getQxname()+"下的街道有：");
42 Set<Jd> set=qx.getJds();
43 for(Jd jd:set){
44 System.out.println(jd.getJdname());
45 }
46 }
47 @Test
48 //单向多对一 /双向多对一（使用时注意只能在实体类多的一方建一的一方对象，不能两边都创建）
49 public void testManyToOne(){
50 Jd jd= (Jd) session.get(Jd.class,1);
51 System.out.println(jd.getJdname()+"属于");
52 System.out.println(jd.getQx().getQxname());
53 }
54
55
56 @After
57 public void tearDowm(){
58 session.close();
59 }
60 }
Demo
3.双向多对多
1.实体类
1 package cn.yunhe.entity;
2
3 import javax.persistence.*;
4 import java.util.HashSet;
5 import java.util.Set;
6
7 @Entity
8 @Table(name = "student")
9 public class Student {//学生表
10 private int id;
11 private String name;
12 public Set<Teacher> teachers =new HashSet<Teacher>();//互相建对方的set集合
13
14 @Id
15 @GeneratedValue
16 @Column(name = "id")
17 public int getId() {
18 return id;
19 }
20
21 public void setId(int id) {
22 this.id = id;
23 }
24
25 @Column(name = "name")
26 public String getName() {
27 return name;
28 }
29
30 public void setName(String name) {
31 this.name = name;
32 }
33
34 @ManyToMany(cascade = CascadeType.ALL,fetch = FetchType.LAZY)
35 //配置中间表，并将外键对照起来
36 @JoinTable(name = "student_teacher",
37 joinColumns = @JoinColumn(name = "studentid"),
38 inverseJoinColumns = @JoinColumn(name ="teacherid"))
39 public Set<Teacher> getTeachers() {
40 return teachers;
41 }
42
43 public void setTeachers(Set<Teacher> teachers) {
44 this.teachers = teachers;
45 }
46 }
student
1 package cn.yunhe.entity;
2
3 import javax.persistence.*;
4 import java.util.HashSet;
5 import java.util.Set;
6
7
8 @Entity
9 @Table(name = "teacher")
10 public class Teacher {//教师
11 private int id;
12 private String name;
13 public Set<Student> students =new HashSet<Student>();//互相建对方的集合
14
15 @Id
16 @GeneratedValue
17 @Column(name = "id")
18 public int getId() {
19 return id;
20 }
21
22 public void setId(int id) {
23 this.id = id;
24 }
25
26 @Column(name = "name")
27 public String getName() {
28 return name;
29 }
30
31 public void setName(String name) {
32 this.name = name;
33 }
34
35 @ManyToMany(cascade = CascadeType.ALL,
36 fetch = FetchType.LAZY,mappedBy = "teachers")
37 public Set<Student> getStudents() {
38 return students;
39 }
40
41 public void setStudents(Set<Student> students) {
42 this.students = students;
43 }
44 }
teacher
2.测试类
1 import cn.yunhe.entity.Jd;
2 import cn.yunhe.entity.Qx;
3 import cn.yunhe.entity.Student;
4 import cn.yunhe.entity.Teacher;
5 import org.hibernate.Session;
6 import org.hibernate.SessionFactory;
7 import org.hibernate.Transaction;
8 import org.hibernate.cfg.AnnotationConfiguration;
9 import org.hibernate.cfg.Configuration;
10 import org.junit.After;
11 import org.junit.Before;
12 import org.junit.Test;
13
14 import java.util.List;
15 import java.util.Set;
16
17 /**
18 * Created by Administrator on 2017/7/6.
19 */
20 public class Demo {
21 Session session=null;
22 Transaction tr=null;
23
24 @Before
25 public void setUp(){
26 Configuration config=new AnnotationConfiguration().configure();
27 SessionFactory factory= config.buildSessionFactory();
28 session=factory.openSession();
29 tr=session.beginTransaction();
30 }
31
32
33 @Test
34 //双向多对多(要有中间表，实体类互相建对方的对象的Set集合)
35 public void testManyToMany(){
36 //根据学生查老师
37 Student student= (Student) session.get(Student.class,5);
38 System.out.println("学生："+student.getName()+"的老师有：");
39 Set<Teacher> teachers=student.getTeachers();
40 for (Teacher t:teachers){
41 System.out.println(t.getName());
42 }
43
44 //根据老师查学生
45 Teacher teacher= (Teacher) session.get(Teacher.class,4);
46 System.out.println("老师："+teacher.getName()+"的学生有：");
47 Set<Student> students=teacher.getStudents();
48 for (Student s:students){
49 System.out.println(s.getName());
50 }
51 }
52
53 @After
54 public void tearDowm(){
55 session.close();
56 }
57 }
Demo
3.主配置文件
1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE hibernate-configuration 3 PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" 4 "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> 5 <hibernate-configuration> 6 <session-factory> 7 <property name="hibernate.hbm2ddl.auto" >update</property><!--自动生成数据库表--> 8 <property name="dialect">org.hibernate.dialect.MySQLDialect</property><!--数据库方言--> 9 <property name="connection.driver_class">com.mysql.jdbc.Driver</property> 10 <property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property> 11 <property name="connection.username">root</property> 12 <property name="connection.password">1234</property> 13 <property name="show_sql">true</property><!--显示sql--> 14 15 <mapping class="cn.yunhe.entity.Student"/> 16 <mapping class="cn.yunhe.entity.Teacher"/> 17 18 </session-factory> 19 </hibernate-configuration>
hibernate.cfg.xml
时间： 2024-10-12 11:54:21