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Hibernate编写多对多单向关系的CRUD操作

项目架构

本项目主要配置了一个基于Hibernate的多对多关系CRUD操作系统。系统采用Java语言编写，使用Hibernate框架进行持久化操作。项目的主要分层结构如下：

• 实体类：定义了两个主表Student和Teacher，分别对应学生和教师信息。
• 关系类：通过@ManyToMany注解定义两个实体之间的多对多关系，用@JoinTable指定了中间关联表T_S，并配置了外键匹配条件。
• 持久化配置：通过Hibernate的XML配置文件hibernate.cfg.xml配置了数据库连接信息、getSessionFactory方法等。

实现功能

本项目主要实现了以下功能：

代码实现

实体类

@Entity@Table(name = "student")public class Student {    private int id;    private String name;    private int age;    private String sex;    @Id    @GeneratedValue    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }}

@Entitypublic class Teacher {    private int id;    private String name;    private int age;    private String sex;    private List
   
     students = new ArrayList<>();    @Id    @GeneratedValue    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public void setName(String name) {        this.name = name;    }    public String getSex() {        return sex;    }    public void setSex(String sex) {        this.sex = sex;    }    @ManyToMany    @JoinTable(name = "T_S", joinColumns = @JoinColumn(name = "T_id"), inverseJoinColumns = @JoinColumn(name = "S_id"))    public List
    
      getStudents() {        return students;    }    public void setStudents(List
     
       students) {        this.students = students;    }}
     
    
   

测试类

public class Text {    public void save() {        Session session = HibernateUtil.getSessionFactory().getCurrentSession();        session.beginTransaction();        Random rm = new Random();        List
   
     teachers = new ArrayList<>();        List
    
      students = new ArrayList<>();        for (int i = 0; i < 10; i++) {            Teacher t1 = new Teacher();            t1.setId(i);            t1.setName("高辉" + i);            t1.setAge(20);            t1.setSex(sex[rm.nextInt(2)]);            teachers.add(t1);            Student s1 = new Student();            s1.setId(i);            s1.setName("陈明" + i);            s1.setAge(30);            s1.setSex(sex[rm.nextInt(2)]);            students.add(s1);        }        for (int i = 0; i < 10; i++) {            for (int j = 9; j > 0; j--) {                teachers.get(i).getStudents().add(students.get(j));            }            session.save(students.get(i));            session.save(teachers.get(i));        }        session.getTransaction().commit();        HibernateUtil.getSessionFactory().close();    }    public void get() {        Session session = HibernateUtil.getSessionFactory().getCurrentSession();        session.beginTransaction();        Query query = session.createQuery("from Student s1 where s1.id > :n and s1.id < :m");        Query query1 = session.createQuery("from Teacher t1 where t1.id > :n and t1.id < :m");        query.setParameter("n", 3);        query.setParameter("m", 8);        query1.setParameter("n", 3);        query1.setParameter("m", 8);        List
     
       list = (List
      
       ) query.list();        List
       
         teacherList = (List
        
         ) query1.list(); System.out.println("id大于3小于8的教师有:"); for (Teacher t1 : teacherList) { System.out.println(t1.getName()); } System.out.println("id大于3小于8的学生有:"); for (Student s1 : list) { System.out.println(s1.getName()); } session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); } public void getconnect() { Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); Query query = session.createQuery("from Teacher t1 where t1.id > :n and t1.id < :m"); query.setParameter("n", 4); query.setParameter("m", 9); List
         
           teacherList = (List
          
           ) query.list(); for (Teacher t1 : teacherList) { System.out.println("教师" + t1.getName() + "的学生有:"); for (Student s1 : t1.getStudents()) { System.out.println(s1.getName()); } } session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); } public void del() { Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); Teacher t1 = new Teacher(); t1 = (Teacher) session.get(Teacher.class, 1); session.delete(t1); Teacher t2 = new Teacher(); t2 = (Teacher) session.get(Teacher.class, 4); session.delete(t2); session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); } public void up() { Session session = HibernateUtil.getSessionFactory().getCurrentSession(); session.beginTransaction(); Teacher t2 = new Teacher(); t2 = (Teacher) session.get(Teacher.class, 2); t2.setName("李明"); t2.setSex("男"); t2.setAge(20); session.update(t2); Student s1 = new Student(); s1 = (Student) session.get(Student.class, 1); s1.setName("李雷"); s1.setSex("男"); s1.setAge(18); session.getTransaction().commit(); HibernateUtil.getSessionFactory().close(); }}
          
         
        
       
      
     
    
   

Hibernate工具类

public class HibernateUtil {    private static final SessionFactory sessionFactory;    static {        try {            Configuration cfg = new Configuration().configure();            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(cfg.getProperties()).build();            sessionFactory = cfg.buildSessionFactory(serviceRegistry);        } catch (Throwable e) {            throw new ExceptionInInitializerError(e);        }    }    public static SessionFactory getSessionFactory() {        return sessionFactory;    }}

Hibernate配置文件

       
            
     
      com.mysql.jdbc.Driver
             
     
      jdbc:mysql://localhost:3306/user
             
     
      root
             
             
     
      2
             
     
      org.hibernate.dialect.MySQL5Dialect
             
     
      thread
             
     
      org.hibernate.cache.internal.NoCacheProvider
             
     
      false
             
     
      false
             
     
      update