Hibernate一对多（注解）

Posted 2020-08-21 走在一线的码农

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 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 <!-- Generated by MyEclipse Hibernate Tools.                   -->
 7 <hibernate-configuration>
 8 
 9 <session-factory>
10     <property name="dialect">
11         org.hibernate.dialect.mysqlDialect
12     </property>
13     <property name="connection.url">
14         jdbc:mysql://localhost:3306/student
15     </property>
16     <property name="connection.username">root</property>
17     <property name="connection.password">123</property>
18     <property name="connection.driver_class">
19         com.mysql.jdbc.Driver
20     </property>
21     <property name="myeclipse.connection.profile">MySQL</property>
22     <property name="show_sql">true</property>
23     <!-- 格式化显示SQL -->
24     <property name="format_sql">true</property>
25 
26     <property name="current_session_context_class">thread</property>
27     <!-- 让hibernate自动创建表  update:如果没有表则创建，有表则更新 -->
28     <property name="hbm2ddl.auto">create</property>
29     <mapping class="cqvie.yjq.domain.School" />
30     <mapping class="cqvie.yjq.domain.Student" />
31 </session-factory>
32 
33 </hibernate-configuration>

Hibernate.cfg.xml

 1 package cqvie.yjq.domain;
 2 
 3 import java.io.Serializable;
 4 
 5 import javax.persistence.Column;
 6 import javax.persistence.Entity;
 7 import javax.persistence.GeneratedValue;
 8 import javax.persistence.Id;
 9 import javax.persistence.Table;
10 
11 import org.hibernate.annotations.GenericGenerator;
12 
13 @Entity
14 @Table(name = "school_2", catalog = "test")
15 public class School implements Serializable {
16 
17     private static final long serialVersionUID = -9135891983324864046L;
18     
19     @Id
20     @GenericGenerator(name = "generator", strategy = "uuid")
21     @GeneratedValue(generator = "generator")
22     @Column(name = "s_num", unique = true, nullable = false)
23     private String s_num;
24     @Column(name = "s_name", length = 50, nullable = false)
25     private String s_name;
26     @Column(name = "s_addr", length = 100, nullable = false)
27     private String s_addr;
28     
29     public String getS_num() {
30         return s_num;
31     }
32     public void setS_num(String sNum) {
33         s_num = sNum;
34     }
35     public String getS_name() {
36         return s_name;
37     }
38     public void setS_name(String sName) {
39         s_name = sName;
40     }
41     public String getS_addr() {
42         return s_addr;
43     }
44     public void setS_addr(String sAddr) {
45         s_addr = sAddr;
46     }
47 }

实体类School

 1 package cqvie.yjq.domain;
 2 
 3 import java.io.Serializable;
 4 
 5 import javax.persistence.CascadeType;
 6 import javax.persistence.Column;
 7 import javax.persistence.Entity;
 8 import javax.persistence.GeneratedValue;
 9 import javax.persistence.Id;
10 import javax.persistence.JoinColumn;
11 import javax.persistence.ManyToOne;
12 import javax.persistence.Table;
13 
14 import org.hibernate.annotations.GenericGenerator;
15 
16 @Entity
17 @Table(name = "student_2", catalog = "test")
18 public class Student implements Serializable {
19 
20     private static final long serialVersionUID = 7571983435023574040L;
21     
22     @Id
23     @GenericGenerator(name = "generator", strategy = "uuid")
24     @GeneratedValue( generator = "generator")
25     @Column(name = "id", nullable = false, unique = true)
26     private String id;
27     
28     @Column(name = "name", nullable = false, length = 20)
29     private String name;
30     
31     @Column(name = "age", nullable = false, length = 3)
32     private int age;
33     
34     @ManyToOne(cascade={CascadeType.ALL})
35     @JoinColumn(name = "s_num")
36     private School school;
37     
38     public School getSchool() {
39         return school;
40     }
41     public void setSchool(School school) {
42         this.school = school;
43     }
44     public String getId() {
45         return id;
46     }
47     public void setId(String id) {
48         this.id = id;
49     }
50     public String getName() {
51         return name;
52     }
53     public void setName(String name) {
54         this.name = name;
55     }
56     public int getAge() {
57         return age;
58     }
59     public void setAge(int age) {
60         this.age = age;
61     }
62 }

实体类Student

 1 package cqvie.yjq.View;
 2 
 3 import org.hibernate.Session;
 4 import org.hibernate.Transaction;
 5 
 6 import cqvie.yjq.Util.HibernataUtil;
 7 import cqvie.yjq.domain.School;
 8 import cqvie.yjq.domain.Student;
 9 
10 
11 public class Test {
12 
13     public static void main(String[] args) {
14 
15         Session session = null;
16         Transaction tx = null;
17         try {
18             session =  HibernataUtil.getCurrentSession();
19             tx = session.beginTransaction();
20             //添加
21             School sc = new School();
22             sc.setS_name("重庆工业职业技术学院");
23             sc.setS_addr("重庆渝北");
24             
25             Student stu = new Student();
26             stu.setSchool(sc);
27             stu.setAge(17);
28             stu.setName("马士兵");
29             
30             session.save(stu);
31             
32             tx.commit();
33         } catch (Exception e) {
34             if(tx != null) {
35                 tx.rollback();
36             }
37         } finally {
38             if(session != null && session.isOpen()) {
39                 session.close();
40             }
41         }
42         
43     }
44 }

测试类Test

package cqvie.yjq.Util;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.AnnotationConfiguration;

final public class HibernataUtil {

    private static SessionFactory sessionFactory = null;
    //使用线程局部模式
    private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
    private HibernataUtil() {};
    static {
        sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
    }
    //获取全新的session
    public static Session openSession() {
        return sessionFactory.openSession();
    }
    //获取和线程关联的session
    public static Session getCurrentSession() {
        Session session = threadLocal.get();
        //判断是否得到
        if(session == null) {
            session = sessionFactory.openSession();
            //把session对象设置到threadLocal，相当于已经和线程绑定
            threadLocal.set(session);
        }
        return session;
    }
    
    //提供一个统一的修改和删除方法（批量）
    public static void executeUpdate(String hql, String[] parameters) {
        Session s = null;
        Transaction ts = null;
        try {
            s = openSession();
            ts = s.beginTransaction();
            Query query = s.createQuery(hql);
            //先判断是否有参数要绑定
            if(parameters != null && parameters.length > 0) {
                for(int i=0;i<parameters.length;i++) {
                    query.setString(i, parameters[i]);
                }
            }
            query.executeUpdate();
            ts.commit();
        } catch(Exception e) {
            e.printStackTrace();
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
    }
    
    //提供一个统一的添加方法
    public static void sava(Object obj) {
        Session s = null;
        Transaction ts = null;
        try {
            s = openSession();
            ts = s.beginTransaction();
            s.save(obj);
            ts.commit();
        } catch (Exception e) {
            if(ts != null) {
                ts.rollback();
            }
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
    }
    
    //提供一个统一的查询方法（分页）
    @SuppressWarnings("unchecked")
    public static List executeQueryByPage(String hql, String[] parameters, int pageSize, int pageNow) {
        Session s = null;
        List list = null;
        try {
            s = openSession();
            Query query = s.createQuery(hql);
            //先判断是否有参数要绑定
            if(parameters != null && parameters.length > 0) {
                for(int i=0;i<parameters.length;i++) {
                    query.setString(i, parameters[i]);
                }
            }
            query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);
            list = query.list();
        } catch(Exception e) {
            e.printStackTrace();
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
        return list;
    }
    
    
    //提供一个统一的查询方法 hql 形式 from 类 where 条件=?
    @SuppressWarnings("unchecked")
    public List executeQuery(String hql, String[] parameters) {
        Session s = null;
        List list = null;
        try {
            s = openSession();
            Query query = s.createQuery(hql);
            //先判断是否有参数要绑定
            if(parameters != null && parameters.length > 0) {
                for(int i=0;i<parameters.length;i++) {
                    query.setString(i, parameters[i]);
                }
            }
            list = query.list();
        } catch(Exception e) {
            e.printStackTrace();
            throw new RuntimeException();
        } finally {
            if(s != null && s.isOpen()) {
                s.close();
            }
        }
        return list;
    }
}

工具类HibernateUtil

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