Hibernate多对一（注解）

Posted 2020-08-21 走在一线的码农

  1 package cqvie.yjq.Util;
  2 
  3 import java.util.List;
  4 
  5 import org.hibernate.Query;
  6 import org.hibernate.Session;
  7 import org.hibernate.SessionFactory;
  8 import org.hibernate.Transaction;
  9 import org.hibernate.cfg.AnnotationConfiguration;
 10 
 11 final public class HibernataUtil {
 12 
 13     private static SessionFactory sessionFactory = null;
 14     //使用线程局部模式
 15     private static ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
 16     private HibernataUtil() {};
 17     static {
 18         sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
 19     }
 20     //获取全新的session
 21     public static Session openSession() {
 22         return sessionFactory.openSession();
 23     }
 24     //获取和线程关联的session
 25     public static Session getCurrentSession() {
 26         Session session = threadLocal.get();
 27         //判断是否得到
 28         if(session == null) {
 29             session = sessionFactory.openSession();
 30             //把session对象设置到threadLocal，相当于已经和线程绑定
 31             threadLocal.set(session);
 32         }
 33         return session;
 34     }
 35     
 36     //提供一个统一的修改和删除方法（批量）
 37     public static void executeUpdate(String hql, String[] parameters) {
 38         Session s = null;
 39         Transaction ts = null;
 40         try {
 41             s = openSession();
 42             ts = s.beginTransaction();
 43             Query query = s.createQuery(hql);
 44             //先判断是否有参数要绑定
 45             if(parameters != null && parameters.length > 0) {
 46                 for(int i=0;i<parameters.length;i++) {
 47                     query.setString(i, parameters[i]);
 48                 }
 49             }
 50             query.executeUpdate();
 51             ts.commit();
 52         } catch(Exception e) {
 53             e.printStackTrace();
 54             throw new RuntimeException();
 55         } finally {
 56             if(s != null && s.isOpen()) {
 57                 s.close();
 58             }
 59         }
 60     }
 61     
 62     //提供一个统一的添加方法
 63     public static void sava(Object obj) {
 64         Session s = null;
 65         Transaction ts = null;
 66         try {
 67             s = openSession();
 68             ts = s.beginTransaction();
 69             s.save(obj);
 70             ts.commit();
 71         } catch (Exception e) {
 72             if(ts != null) {
 73                 ts.rollback();
 74             }
 75             throw new RuntimeException();
 76         } finally {
 77             if(s != null && s.isOpen()) {
 78                 s.close();
 79             }
 80         }
 81     }
 82     
 83     //提供一个统一的查询方法（分页）
 84     @SuppressWarnings("unchecked")
 85     public static List executeQueryByPage(String hql, String[] parameters, int pageSize, int pageNow) {
 86         Session s = null;
 87         List list = null;
 88         try {
 89             s = openSession();
 90             Query query = s.createQuery(hql);
 91             //先判断是否有参数要绑定
 92             if(parameters != null && parameters.length > 0) {
 93                 for(int i=0;i<parameters.length;i++) {
 94                     query.setString(i, parameters[i]);
 95                 }
 96             }
 97             query.setFirstResult((pageNow-1)*pageSize).setMaxResults(pageSize);
 98             list = query.list();
 99         } catch(Exception e) {
100             e.printStackTrace();
101             throw new RuntimeException();
102         } finally {
103             if(s != null && s.isOpen()) {
104                 s.close();
105             }
106         }
107         return list;
108     }
109     
110     
111     //提供一个统一的查询方法 hql 形式 from 类 where 条件=?
112     @SuppressWarnings("unchecked")
113     public List executeQuery(String hql, String[] parameters) {
114         Session s = null;
115         List list = null;
116         try {
117             s = openSession();
118             Query query = s.createQuery(hql);
119             //先判断是否有参数要绑定
120             if(parameters != null && parameters.length > 0) {
121                 for(int i=0;i<parameters.length;i++) {
122                     query.setString(i, parameters[i]);
123                 }
124             }
125             list = query.list();
126         } catch(Exception e) {
127             e.printStackTrace();
128             throw new RuntimeException();
129         } finally {
130             if(s != null && s.isOpen()) {
131                 s.close();
132             }
133         }
134         return list;
135     }
136 }

工具类HibernateUtil

 1 package cqvie.yjq.domain;
 2 
 3 import javax.persistence.Column;
 4 import javax.persistence.Entity;
 5 import javax.persistence.GeneratedValue;
 6 import javax.persistence.Id;
 7 import javax.persistence.Table;
 8 
 9 import org.hibernate.annotations.GenericGenerator;
10 
11 @Entity
12 @Table(name = "department_", catalog = "test")
13 public class Department implements java.io.Serializable {
14 
15     private static final long serialVersionUID = 2076837731637660357L;
16     
17     @Id
18     @GenericGenerator(name = "generator", strategy = "uuid")
19     @GeneratedValue(generator = "generator")
20     @Column(name = "depid", unique = true, nullable = false)//nullable = false表示该字段不为空
21     private String depid;
22     @Column(name = "name", nullable = false, length = 20)
23     private String name;
24     
25     public String getDepid() {
26         return depid;
27     }
28     public void setDepid(String depid) {
29         this.depid = depid;
30     }
31     public String getName() {
32         return name;
33     }
34     public void setName(String name) {
35         this.name = name;
36     }
37     
38 }

实体类Department

 1 package cqvie.yjq.domain;
 2 
 3 import javax.persistence.Column;
 4 import javax.persistence.Entity;
 5 import javax.persistence.GeneratedValue;
 6 import javax.persistence.Id;
 7 import javax.persistence.JoinColumn;
 8 import javax.persistence.ManyToOne;
 9 import javax.persistence.Table;
10 
11 import org.hibernate.annotations.GenericGenerator;
12 
13 
14 @Entity
15 @Table(name = "student_", catalog = "test")
16 public class Student implements java.io.Serializable {
17 
18     private static final long serialVersionUID = 8640757615294410421L;
19     
20     @Id
21     @GenericGenerator(name = "generator", strategy = "uuid")
22     @GeneratedValue(generator = "generator")
23     @Column(name = "stuid", unique = true, nullable = false)
24     private String stuid;
25     @Column(name = "name", nullable = false, length = 20)
26     private String name;
27     @ManyToOne
28     @JoinColumn(name = "depid")
29     private Department dept;
30     
31     public String getStuid() {
32         return stuid;
33     }
34     public void setStuid(String stuid) {
35         this.stuid = stuid;
36     }
37     public String getName() {
38         return name;
39     }
40     public void setName(String name) {
41         this.name = name;
42     }
43     public Department getDept() {
44         return dept;
45     }
46     public void setDept(Department dept) {
47         this.dept = dept;
48     }
49     
50     
51 }

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.Department;
 8 import cqvie.yjq.domain.Student;
 9 
10 public class Test {
11 
12     public static void main(String[] args) {
13 
14         //通过获取session让hibernate框架运行(config --> 加载hibernate.cfg.xml)
15         Session session = null;
16         Transaction tx = null;
17         try {
18             session =  HibernataUtil.getCurrentSession();
19             tx = session.beginTransaction();
20 
21             Student stu = new Student();
22             stu.setName("王敏");
23             
24             Department dep = new Department();
25             dep.setName("财务部");
26             Department dep1 = new Department();
27             dep1.setName("人事部");
28             
29             stu.setDept(dep1);
30             
31             session.save(stu);
32             session.save(dep);
33             session.save(dep1);
34             
35             tx.commit();
36         } catch (Exception e) {
37             if(tx != null) {
38                 tx.rollback();
39             }
40         } finally {
41             if(session != null && session.isOpen()) {
42                 session.close();
43             }
44         }
45     }
46 
47 }

测试类

 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.Department" />
30     <mapping class="cqvie.yjq.domain.Student" />
31 </session-factory>
32 
33 </hibernate-configuration>

Hibernate.cfg.xml