Hibernate+maven+mysql处理多对多映射-CFANZ编程社区

一代码

1.1项目结构

Hibernate+maven+mysql处理多对多映射_java

1.2pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <groupId>org.example</groupId>
   <artifactId>Hibernate-Test</artifactId>
   <version>1.0-SNAPSHOT</version>
   <build>
       <plugins>
           <plugin>
               <groupId>org.mortbay.jetty</groupId>
               <artifactId>maven-jetty-plugin</artifactId>
               <version>6.1.7</version>
               <configuration>
                   <connectors>
                       <connector implementation="org.mortbay.jetty.nio.SelectChannelConnector">
                           <port>8888</port>
                           <maxIdleTime>30000</maxIdleTime>
                       </connector>
                   </connectors>
                   <webAppSourceDirectory>${project.build.directory}/${pom.artifactId}-${pom.version}</webAppSourceDirectory>
                   <contextPath>/</contextPath>
               </configuration>
           </plugin>
       </plugins>
       <!--把xml文件也编译-->
       <resources>
           <resource>
               <directory>src/main/java</directory>
               <includes>
                   <include>**/*.xml</include>
               </includes>
           </resource>
           <resource>
               <directory>src/main/resources</directory>
               <includes>
                   <include>**/*.xml</include>
               </includes>
           </resource>
       </resources>
   </build>
   <properties>
       <maven.compiler.source>8</maven.compiler.source>
       <maven.compiler.target>8</maven.compiler.target>
   </properties>
   <dependencies>
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.10</version>
           <scope>test</scope>
       </dependency>

       <!-- 添加Hibernate依赖 -->
       <dependency>
           <groupId>org.hibernate</groupId>
           <artifactId>hibernate-core</artifactId>
           <version>3.6.5.Final</version>
       </dependency>

       <!-- 添加Log4J依赖 -->
       <dependency>
           <groupId>log4j</groupId>
           <artifactId>log4j</artifactId>
           <version>1.2.16</version>
       </dependency>

       <dependency>
           <groupId>org.slf4j</groupId>
           <artifactId>slf4j-api</artifactId>
           <version>1.6.1</version>
       </dependency>

       <dependency>
           <groupId>org.slf4j</groupId>
           <artifactId>slf4j-nop</artifactId>
           <version>1.6.4</version>
       </dependency>

       <!-- 添加javassist -->
       <dependency>
           <groupId>javassist</groupId>
           <artifactId>javassist</artifactId>
           <version>3.11.0.GA</version>
       </dependency>
       <dependency>
           <groupId>org.junit.jupiter</groupId>
           <artifactId>junit-jupiter-api</artifactId>
           <version>RELEASE</version>
       </dependency>
       <dependency>
           <groupId>junit</groupId>
           <artifactId>junit</artifactId>
           <version>4.12</version>
       </dependency>
       <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>5.0.8</version>
       </dependency>
   </dependencies>

</project>

1.3hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
       "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
   <session-factory>
       <!-- Database connection settings -->
       <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
       <property name="connection.url">jdbc:mysql://localhost:3306/cars</property>
       <property name="connection.username">root</property>
       <property name="connection.password">root</property>
       <!--显示生成的sql语句-->
       <property name="show_sql">true</property>
       <property name="format_sql">true</property>
       <!-- 禁用了javaEE6的bean-validate -->
       <property name="javax.persistence.validation.mode">none</property>
       <property name="dialect">org.hibernate.dialect.SQLServerDialect</property>
       <!-- 即可通过getCurrentSession 获取线程唯一的session -->
       <property name="current_session_context_class">thread</property>

       <!--在数据库中自动创建表-->
       <!--<property name="hbm2ddl.auto">update</property>-->
       <!-- 指定ddl的生成方式 -->
       <!--<property name="hibernate.hbm2ddl.auto">create</property>-->

       <mapping resource="com/test/model/PersonEntity.hbm.xml"/>

       <mapping class="com.test.model.Student"/>
       <mapping class="com.test.model.Teacher"/>
       <mapping class="com.test.model.TeacherStudent"/>
   </session-factory>
</hibernate-configuration>

1.4HibernateUtil

package com.test.utils;

/**
* @Author yqq
* @Date 2021/6/22 0:36
* @Version 1.0
*/
import org.apache.log4j.Logger;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
   /** ThreadLocal Session Map */
   public static final ThreadLocal<Session> SESSIONMAP = new ThreadLocal<Session>();
   private static final SessionFactory sessionFactory;
   private static final Logger LOGGER = Logger.getLogger(HibernateUtil.class);

   static {
       try {
           LOGGER.debug("HibernateUti.static - loading cofig");
           sessionFactory = new Configuration().configure("hibernate.cfg.xml")
                   .buildSessionFactory();
           LOGGER.debug("HibernateUtil.static - end");
       } catch (Throwable ex) {
           ex.printStackTrace();
           LOGGER.error("HibernateUti error : ExceptionInInitializerError");
           throw new ExceptionInInitializerError(ex);
       }
   }

   private HibernateUtil() {

   }

   public static Session getSession() throws HibernateException {
       Session session = SESSIONMAP.get();

       if(session == null) {
           session = sessionFactory.openSession();
           SESSIONMAP.set(session);
       }

       return session;
   }

   public static void closeSession() throws HibernateException {
       Session session = SESSIONMAP.get();
       SESSIONMAP.set(null);

       if(session != null) {
           session.close();
       }
   }

}

1.5Student

package com.test.model;

import javax.persistence.*;
import java.io.Serializable;
import java.util.Date;
import java.util.Set;

/**
* @Author yqq
* @Date 2021/6/24 22:37
* @Version 1.0
*/
@Entity
@Table(name = "T_STUDENT")
@SequenceGenerator(name = "SEQ_STUDENT", sequenceName = "SEQ_STUDENT")
public class Student implements Serializable {
   private static final long serialVersionUID = 2524659555729848644L;
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY, generator = "SEQ_STUDENT")
   @Column(name = "ID", nullable = false, precision = 22, scale = 0)
   private Long id;
   @Column(name = "NAME")
   private String name;
   @Temporal(TemporalType.DATE)
   @Column(name = "BIRTHDAY")
   private Date birthday;
   @Column(name = "sex")
   private int sex;
   @Column(name = "address")
   private String address;
   @OneToMany(mappedBy="student",cascade=CascadeType.ALL)
   private Set<TeacherStudent> teacherStudentList;

   public Long getId() {
       return id;
   }
   public void setId(Long id) {
       this.id = id;
   }

   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }

   public Date getBirthday() {
       return birthday;
   }
   public void setBirthday(Date birthday) {
       this.birthday = birthday;
   }

   public int getSex() {
       return sex;
   }
   public void setSex(int sex) {
       this.sex = sex;
   }

   public String getAddress() {
       return address;
   }
   public void setAddress(String address) {
       this.address = address;
   }

   public Set<TeacherStudent> getTeacherStudentList() {
       return teacherStudentList;
   }
   public void setTeacherStudentList(Set<TeacherStudent> teacherStudentList) {
       this.teacherStudentList = teacherStudentList;
   }
}

1.6Teacher

package com.test.model;
import javax.persistence.*;
import java.io.Serializable;
import java.util.Date;
import java.util.Set;

/**
* @Author yqq
* @Date 2021/6/24 22:38
* @Version 1.0
*/
@Entity
@Table(name = "T_TEACHER")
@SequenceGenerator(name = "SEQ_TEACHER", sequenceName = "SEQ_TEACHER")
public class Teacher implements Serializable {
   private static final long serialVersionUID = 2297316923535111793L;
   private Long id;
   private String name;
   private int sex;
   private Set<TeacherStudent> teacherStudentList;
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY, generator = "SEQ_TEACHER")
   @Column(name = "ID", nullable = false, precision = 22, scale = 0)
   public Long getId() {
       return id;
   }
   public void setId(Long id) {
       this.id = id;
   }
   @Column(name = "name")
   public String getName() {
       return name;
   }
   public void setName(String name) {
       this.name = name;
   }
   @Column(name = "sex")
   public int getSex() {
       return sex;
   }
   public void setSex(int sex) {
       this.sex = sex;
   }
   @OneToMany(mappedBy = "teacher",cascade=CascadeType.ALL)
   public Set<TeacherStudent> getTeacherStudentList() {
       return teacherStudentList;
   }
   public void setTeacherStudentList(Set<TeacherStudent> teacherStudentList) {
       this.teacherStudentList = teacherStudentList;
   }
}

1.7TeacherStudent

package com.test.model;
import javax.persistence.*;
import java.io.Serializable;

/**
* @Author yqq
* @Date 2021/6/24 22:39
* @Version 1.0
*/
@Entity
@Table(name = "T_TEACHERSTUDENT")
@SequenceGenerator(name = "SEQ_TEACHERSTUDENT", sequenceName = "SEQ_TEACHERSTUDENT")
public class TeacherStudent implements Serializable {
   private Long id;
   private Student student;
   private Teacher teacher;
   private String note1;
   private String note2;
   @Id
   @GeneratedValue(strategy = GenerationType.IDENTITY, generator = "SEQ_TEACHERSTUDENT")
   @Column(name = "ID", nullable = false, precision = 22, scale = 0)
   public Long getId() {
       return id;
   }
   public void setId(Long id) {
       this.id = id;
   }
   @Column(name = "note11")
   public String getNote1() {
       return note1;
   }
   public void setNote1(String note1) {
       this.note1 = note1;
   }
   @Column(name = "note22")
   public String getNote2() {
       return note2;
   }
   public void setNote2(String note2) {
       this.note2 = note2;
   }
   @ManyToOne(cascade=CascadeType.ALL)
   @JoinColumn(name = "student_id", unique = true)
   public Student getStudent() {
       return student;
   }
   public void setStudent(Student student) {
       this.student = student;
   }
   @ManyToOne
   @JoinColumn(name = "teacher_id", unique = true)
   public Teacher getTeacher() {
       return teacher;
   }
   public void setTeacher(Teacher teacher) {
       this.teacher = teacher;
   }
}

1.8ModelTest

@Test
public void tests(){
   Session session = HibernateUtil.getSession();
   session.beginTransaction();
   Student s = new Student();
   s.setName("小猪");
   Teacher t = new Teacher();
   t.setName("小李");
   TeacherStudent ts=new TeacherStudent();
   ts.setStudent(s);
   ts.setTeacher(t);
   ts.setNote1("以呀呀！！！");
   ts.setNote2("哎哎呀");
   session.save(s);
   session.save(t);
   session.save(ts);
   session.getTransaction().commit();
   HibernateUtil.closeSession();
}

二数据脚本

2.1从表

注意：该表两个外键（student_id，teacher_id）分别指向相应表的ID

DROP TABLE IF EXISTS `t_teacherstudent`;
CREATE TABLE `t_teacherstudent` (
 `ID` int(11) NOT NULL AUTO_INCREMENT,
 `note11` varchar(255) NOT NULL,
 `note22` varchar(255) NOT NULL,
 `student_id` int(11) DEFAULT NULL,
 `teacher_id` int(11) DEFAULT NULL,
 PRIMARY KEY (`ID`),
 KEY `sid` (`student_id`),
 KEY `tid` (`teacher_id`),
 CONSTRAINT `sid` FOREIGN KEY (`student_id`) REFERENCES `t_student` (`ID`),
 CONSTRAINT `tid` FOREIGN KEY (`teacher_id`) REFERENCES `t_teacher` (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;

2.2主表1

DROP TABLE IF EXISTS `t_teacher`;
CREATE TABLE `t_teacher` (
 `ID` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(255) DEFAULT NULL,
 `sex` int(11) DEFAULT NULL,
 PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

2.3主表2

DROP TABLE IF EXISTS `t_student`;
CREATE TABLE `t_student` (
 `ID` int(11) NOT NULL AUTO_INCREMENT,
 `name` varchar(255) DEFAULT NULL,
 `birthday` varchar(255) DEFAULT NULL,
 `sex` int(255) DEFAULT NULL,
 `address` varchar(255) DEFAULT NULL,
 PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;