Hibernate学习总结

我不是女神ヾ 2022-07-12 01:26 94阅读 0赞

> Hibernate主要是在开发中对Dao（database access object）层进行操作，因为他主要是操作数据库的，所以hibernate主要用于数据库的增删查改，下面就来一一介绍：

1.配置hibernate，在src目录下新建一个名为hibernate.cfg.xml的文件，然后在里面做第一步的配置，在下面的配置中，基本上很直观的知道意思，但是`current_session_context_class` 这个配置需要解释一下，本身hibernate工厂是一个单例，所以无论是哪一个地方的请求，调用的都是同一个对象，但是如果加上  
`<property name="hibernate.current_session_context_class">thread</property>`  
的话，对于每个IP地址，会有一个自己的本地对象。

<?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>
            <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
            <property name="hibernate.connection.url">jdbc:mysql:///xxh</property>
            <property name="hibernate.connection.username">root</property>
            <property name="hibernate.connection.password">123456</property>
    
            <property name="hibernate.show_sql">true</property>
            <property name="hibernate.format_sql">true</property>
    
            <property name="hibernate.hbm2ddl.auto">update</property>
            <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    
    
            <property name="hibernate.current_session_context_class">thread</property>
    
            <mapping resource="com/xiaoxiaohei/entity/User.hbm.xml"/>
            <mapping resource="com/xiaoxiaohei/entity/Customer.hbm.xml"/>
            <mapping resource="com/xiaoxiaohei/entity/LinkMan.hbm.xml"/>
            <mapping resource="com/xiaoxiaohei/entity/Users.hbm.xml"/>
            <mapping resource="com/xiaoxiaohei/entity/Role.hbm.xml"/>
        </session-factory>
    </hibernate-configuration>

2.第二部创建实体类，一般这个包我们命名为entity。实体类中分为3中关系，1对1，1对多，多对多：

> a.一对一关系配置

首先定义实体类，这里需要注意的是，基本类型建议用包装类的定义，下面是一个例子

public class User {
        private Integer uid;
    // private String uid;
        private String username;
        private String password;
        private String address;
        public Integer getUid() {
            return uid;
        }
        public void setUid(Integer uid) {
            this.uid = uid;
        }
        public String getUsername() {
            return username;
        }
        public void setUsername(String username) {
            this.username = username;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }
        public String getAddress() {
            return address;
        }
        public void setAddress(String address) {
            this.address = address;
        }
        @Override
        public String toString() {
            return "User [uid=" + uid + ", username=" + username + ", password=" + password + ", address=" + address + "]";
        }
    
    }

然后创建这个类的配置文件`User.hbm.xml` ，一般主键用native：

> b.一对多关系配置，注意一方对应的类要有多方的Set集合，多方对应的类要有一方的对象。还有配置文件中的many-to-one和one-to-many

public class LinkMan {
        private Integer lkm_id;
        private String lkm_name;
        private String lkm_gender;
        private String lkm_phone;
    
        private Customer customer;
    
    
    
        public Customer getCustomer() {
            return customer;
        }
        public void setCustomer(Customer customer) {
            this.customer = customer;
        }
        public Integer getLkm_id() {
            return lkm_id;
        }
        public void setLkm_id(Integer lkm_id) {
            this.lkm_id = lkm_id;
        }
        public String getLkm_name() {
            return lkm_name;
        }
        public void setLkm_name(String lkm_name) {
            this.lkm_name = lkm_name;
        }
        public String getLkm_gender() {
            return lkm_gender;
        }
        public void setLkm_gender(String lkm_gender) {
            this.lkm_gender = lkm_gender;
        }
        public String getLkm_phone() {
            return lkm_phone;
        }
        public void setLkm_phone(String lkm_phone) {
            this.lkm_phone = lkm_phone;
        }
        @Override
        public String toString() {
            return "LinkMan [lkm_id=" + lkm_id + ", lkm_name=" + lkm_name + ", lkm_gender=" + lkm_gender + ", lkm_phone="
                    + lkm_phone + ", customer=" + customer + "]";
        }
    
    
    }

import java.util.HashSet;
    import java.util.Set;
    
    public class Customer { 
        private Integer cid;
        private String custName;
        private String custLevel;
        private String custSource;
        private String custPhone;
        private String custMobile;
    
        private Set<LinkMan> setLinkMan = new HashSet<>();
    
    
        public Set<LinkMan> getSetLinkMan() {
            return setLinkMan;
        }
        public void setSetLinkMan(Set<LinkMan> setLinkMan) {
            this.setLinkMan = setLinkMan;
        }
        public Integer getCid() {
            return cid;
        }
        public void setCid(Integer cid) {
            this.cid = cid;
        }
        public String getCustName() {
            return custName;
        }
        public void setCustName(String custName) {
            this.custName = custName;
        }
        public String getCustLevel() {
            return custLevel;
        }
        public void setCustLevel(String custLevel) {
            this.custLevel = custLevel;
        }
        public String getCustSource() {
            return custSource;
        }
        public void setCustSource(String custSource) {
            this.custSource = custSource;
        }
        public String getCustPhone() {
            return custPhone;
        }
        public void setCustPhone(String custPhone) {
            this.custPhone = custPhone;
        }
        public String getCustMobile() {
            return custMobile;
        }
        public void setCustMobile(String custMobile) {
            this.custMobile = custMobile;
        }
        @Override
        public String toString() {
            return "Customer [cid=" + cid + ", custName=" + custName + ", custLevel=" + custLevel + ", custSource="
                    + custSource + ", custPhone=" + custPhone + ", custMobile=" + custMobile + "]";
        }
    
    
    
    }

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        
        <class name="com.xiaoxiaohei.entity.Customer" table="customer">
            <id name="cid" column="cid">
                <generator class="native"></generator>
            </id>
            <property name="custName" column="custName"></property>
            <property name="custLevel" column="custLevel"></property>
            <property name="custSource" column="custSource"></property>
            <property name="custPhone" column="custPhone"></property>
            <property name="custMobile" column="custMobile"></property>
            <set name="setLinkMan" cascade="save-update,delete" inverse="true" fetch="select" lazy="extra" batch-size="2">
                <key column="clid"></key>
                <one-to-many class="com.xiaoxiaohei.entity.LinkMan" />
            </set>
        </class>
    </hibernate-mapping>

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        
        <class name="com.xiaoxiaohei.entity.LinkMan" table="link_man">
            <id name="lkm_id" column="lkm_id">
                
                <generator class="native"></generator>
            </id>
            <property name="lkm_name" column="lkm_name"></property>
            <property name="lkm_gender" column="lkm_gender"></property>
            <property name="lkm_phone" column="lkm_phone"></property>
    
            <many-to-one name="customer" class="com.xiaoxiaohei.entity.Customer" column="clid"></many-to-one>
        </class>
    </hibernate-mapping>

> c.多对多关系的配置

import java.util.HashSet;
    import java.util.Set;
    
    import java.util.HashSet;
    import java.util.Set;
    
    public class Role { 
        private Integer role_id;
        private String role_name;
        private String role_memo;
    
        private Set<Users> setUser = new HashSet<>();
    
    
    
        public Set<Users> getSetUser() {
            return setUser;
        }
        public void setSetUser(Set<Users> setUser) {
            this.setUser = setUser;
        }
        public Integer getRole_id() {
            return role_id;
        }
        public void setRole_id(Integer role_id) {
            this.role_id = role_id;
        }
        public String getRole_name() {
            return role_name;
        }
        public void setRole_name(String role_name) {
            this.role_name = role_name;
        }
        public String getRole_memo() {
            return role_memo;
        }
        public void setRole_memo(String role_memo) {
            this.role_memo = role_memo;
        }
    
    
    }

public class Users {
        private Integer user_id;
        private String user_name;
        private String user_password;
    
        private Set<Role> setRole = new HashSet<>();
    
    
    
        public Set<Role> getSetRole() {
            return setRole;
        }
        public void setSetRole(Set<Role> setRole) {
            this.setRole = setRole;
        }
        public Integer getUser_id() {
            return user_id;
        }
        public void setUser_id(Integer user_id) {
            this.user_id = user_id;
        }
        public String getUser_name() {
            return user_name;
        }
        public void setUser_name(String user_name) {
            this.user_name = user_name;
        }
        public String getUser_password() {
            return user_password;
        }
        public void setUser_password(String user_password) {
            this.user_password = user_password;
        }
    
    
    }

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        
        <class name="com.xiaoxiaohei.entity.Role" table="role">
            <id name="role_id" column="role_id">
                
                <generator class="native"></generator>
            </id>
            <property name="role_name" column="role_name"></property>
            <property name="role_memo" column="role_memo"></property>
            <set name="setUser" table="user_role">
                <key column="roleid"></key>
                <many-to-many class="com.xiaoxiaohei.entity.Users" column="userid"></many-to-many>
            </set>
        </class>
    </hibernate-mapping>

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <hibernate-mapping>
        
        <class name="com.xiaoxiaohei.entity.Users" table="users">
            <id name="user_id" column="user_id">
                
                <generator class="native"></generator>
            </id>
            <property name="user_name" column="user_name"></property>
            <property name="user_password" column="user_password"></property>
            <set name="setRole" table="user_role" cascade="save-update,delete">
                <key column="userid"></key>
                <many-to-many class="com.xiaoxiaohei.entity.Role" column="roleid"></many-to-many>
            </set>
    
        </class>
    </hibernate-mapping>

> 对于hibernate的使用，一般我们会封装一个工厂类来实现操作

public class HibernateUtils {
        private static Configuration cfg = null;
        private static SessionFactory sessionFactory = null;
        static {
            cfg = new Configuration();
            cfg.configure();
            sessionFactory = cfg.buildSessionFactory();
        }
    
        public static SessionFactory getSessionFactory() {
            return sessionFactory;
        }
    
        public static Session getSessionObject() {
            return sessionFactory.getCurrentSession();
        }
    
        public static void main(String[] args) {
    
        }
    }

--------------------

> 下面给出demo

1.demo1

public class Demo1 {
        public static void main(String[] args) {
            SessionFactory sessionFactory = HibernateUtils.getSessionFactory();
    
            Session session = sessionFactory.openSession();
    
            Transaction tx = session.beginTransaction();
    
            User user = new User();
    //      user.setUid(5);
            user.setUsername("8888888");
            user.setPassword("123456");
            user.setAddress("锟秸憋拷");
    
            session.save(user);
            /*session.saveOrUpdate(user); System.out.println(user.getUid());*/
    
    //      User user1 = session.get(User.class, 5);
            /*System.out.println(user1); User user2 = session.get(User.class, 5); System.out.println(user2); System.out.println(user1==user2);*/
    
    //      user1.setUsername("bbbbbbb");
    
            tx.commit();
    
    
            session.close();
            sessionFactory.close();
        }
    }

2.demo2

import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.Transaction;
    
    import com.xiaoxiaohei.entity.User;
    import com.xiaoxiaohei.util.HibernateUtils;
    
    public class Demo2 {
    
        public static void main(String[] args) {
            // TODO Auto-generated method stub
            /*SessionFactory sessionFactory = HibernateUtils.getSessionFactory(); Session session = sessionFactory.openSession();*/
    
            Session session = HibernateUtils.getSessionObject();
    
            Transaction tx = session.beginTransaction();
    
    //      User user = session.get(User.class, 2);
    
    //      user.setUsername("uuuuu");
    
    //      session.update(user);
    //      session.save(user);
    
    //      session.delete(user);
    
            User user = new User();
            user.setUid(4);
            session.delete(user);
    
            tx.commit();
    
            System.out.println(user);
    
            session.close();
        }
    
    }

3.demo3

public class Demo3 {
    
        public static void main(String[] args) {
            SessionFactory sessionFactory = null;
            Session session = null;
            Transaction tx = null;
            try {
                sessionFactory = HibernateUtils.getSessionFactory();
    
                session = sessionFactory.openSession();
    
                tx = session.beginTransaction();
    
                User user = new User();
                user.setUsername("iiiiii");
                user.setPassword("1111111");
                user.setAddress("oooooooo");
    
                session.save(user);
    
                tx.commit();
            } catch(Exception e) {
                tx.rollback();
            } finally {
                session.close();
                sessionFactory.close();
            }
        }
    }

4.demo4

public class Demo4 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Query query = session.createQuery("from User");//注意大小写，小写不行
    
                List<User> list = query.list();
    
                for(User u : list) {
                    System.out.println(u);
                }
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

5.demo5

public class Demo5 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Criteria criteria = session.createCriteria(User.class);
    
                List<User> list = criteria.list();
    
                for(User u : list) {
                    System.out.println(u);
                }
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

6.demo6

public class Demo6 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Customer customer = new Customer();
                customer.setCustName("aaaa");
                customer.setCustLevel("vip");
                customer.setCustSource("oooo");
                customer.setCustPhone("2222222");
                customer.setCustMobile("999999");
    
                LinkMan linkMan = new LinkMan();
                linkMan.setLkm_name("uuuuu");
                linkMan.setLkm_gender("nan");
                linkMan.setLkm_phone("ppp");
    
                customer.getSetLinkMan().add(linkMan);
                customer.getSetLinkMan().add(linkMan);
    //          linkMan.setCustomer(customer);
    
                session.save(customer);
    //          session.save(linkMan);
    
    
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

7.demo7

public class Demo7 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Customer customer = session.get(Customer.class, 1);
                session.delete(customer);
    
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

8.demo8

public class Demo8 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Customer baidu = session.get(Customer.class, 3);
                LinkMan lucy = session.get(LinkMan.class, 3);
    
                baidu.getSetLinkMan().add(lucy);
                lucy.setCustomer(baidu);
    
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

9.demo9

public class Demo9 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Users users1 = new Users();
                users1.setUser_name("xxxxxx");
                users1.setUser_password("pppppp");
    
                Users users2 = new Users();
                users2.setUser_name("2222222");
                users2.setUser_password("222222");
    
    
                Role role1 = new Role();
                role1.setRole_name("rrrrrr");
                role1.setRole_memo("mmmmmmm");
    
                Role role2 = new Role();
                role2.setRole_name("22222");
                role2.setRole_memo("222222");
    
                Role role3 = new Role();
                role3.setRole_name("333333");
                role3.setRole_memo("3333333");
    
                users1.getSetRole().add(role1);
                users1.getSetRole().add(role2);
    
                users2.getSetRole().add(role2);
                users2.getSetRole().add(role3);
    
                session.save(users1);
                session.save(users2);
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

10.demo10

public class Demo10 {
        public static void main(String[] args) {
            Session session = null;
            Transaction tx = null;
            try {
                session = HibernateUtils.getSessionObject();
    
                tx = session.beginTransaction();
    
                Users users = session.get(Users.class, 1);
                session.delete(users);
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
    
            }
        }
    }

11.demo11

public class Demo11 {
        public static void main(String[] args) {
            SessionFactory sessionFactory = null;
            Session session = null;
            Transaction tx = null;
            try {
    
                sessionFactory = HibernateUtils.getSessionFactory();
                session = sessionFactory.getCurrentSession();
                tx = session.beginTransaction();
    
                Customer customer = session.get(Customer.class, 2);
    
                Set<LinkMan> set = customer.getSetLinkMan();
    
                for(LinkMan man : set) {
                    System.out.println(man);
                }
    
                tx.commit();
            } catch(Exception e) {
                tx.rollback();
            } finally {
                session.close();
            }
        }
    }

12.demo12

public class Demo12 \{  
public static void main(String\[\] args) \{  
SessionFactory sessionFactory = null;  
Session session = null;  
Transaction tx = null;  
try \{

sessionFactory = HibernateUtils.getSessionFactory();
            session = sessionFactory.getCurrentSession();
            tx = session.beginTransaction();
    
            /*Query<Customer> query = session.createQuery("from Customer", Customer.class);
            List<Customer> list = query.getResultList();
    
            System.out.println(list);
    
            for(Customer c : list) {
                System.err.println(c);
            }*/
            /*for(int i = 0; i < 50; i++) {
                Customer c = new Customer();
                c.setCustName("name---"+i);
                session.save(c);
            }*/
    
            Query<Customer> query = session.createQuery("from Customer order by cid desc", Customer.class);
            query.setFirstResult(0);
            query.setMaxResults(10);
            List<Customer> list = query.getResultList();
    
            for(Customer c : list) {
                System.err.println(c);
            }
    
            tx.commit();
        } catch(Exception e) {
            e.printStackTrace();
            tx.rollback();
        } finally {
            session.close();
        }
    }

13.demo13

public class Demo13 {
        public static void main(String[] args) {
            SessionFactory sessionFactory = null;
            Session session = null;
            Transaction tx = null;
            try {
    
                sessionFactory = HibernateUtils.getSessionFactory();
                session = sessionFactory.getCurrentSession();
                tx = session.beginTransaction();
    
    // Criteria criteria = session.createCriteria(Customer.class);
    
    // criteria.add(Restrictions.eq("cid", 42));
    
                /*criteria.addOrder(Order.desc("cid")); criteria.setFirstResult(0); criteria.setMaxResults(5); List<Customer> list = criteria.list(); for(Customer c : list) { System.out.println(c); }*/
    
                /*criteria.setProjection(Projections.rowCount()); Object obj = criteria.uniqueResult(); Long lobj = (Long) obj; System.out.println(lobj.intValue());*/
    
                /*Query query = session.createQuery("from Customer c inner join c.setLinkMan"); List<Object[]> list = query.list(); for(Object[] obj : list) { System.out.println(obj[0]); System.out.println(obj[1]); }*/
    
                Query query = session.createQuery("from Customer c inner join fetch c.setLinkMan");
                List list = query.list();
    
    
                System.out.println(list);
    
                tx.commit();
            } catch(Exception e) {
                e.printStackTrace();
                tx.rollback();
            } finally {
                session.close();
            }
        }
    }