本文共 3188 字，大约阅读时间需要 10 分钟。

Hibernate是一种ORM（对象关系/关系数据库）框架，其简单概念就是将Java中的对象映射为关系数据库中的表。程序员只需要操作Java中的对象，即只关心业务逻辑操作，Hibernate就会自动将业务逻辑操作翻译为底层SQL语句进行处理，程序员无需关系数据库中的操作。

首先建立POJO对象，这个对象将映射数据库中的表Employee：

package com.ydoing.domain;public class Employee {    private int id;    private String firstName;    private String lastName;    private int salary;    public Employee() {    }    public Employee(String fname, String lname, int salary) {        this.firstName = fname;        this.lastName = lname;        this.salary = salary;    }    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getFirstName() {        return firstName;    }    public void setFirstName(String first_name) {        this.firstName = first_name;    }    public String getLastName() {        return lastName;    }    public void setLastName(String last_name) {        this.lastName = last_name;    }    public int getSalary() {        return salary;    }    public void setSalary(int salary) {        this.salary = salary;    }}

然后建立java对象与关系数据库中的表的关系，用Employee.hbm.xml来描述，放在src目录下：

    
      
          
              This class contains the employee detail.             
              
            
           
           
           
        
    
   

还需要告诉Hibernate数据库的信息，用hibernate.cfg.xml描述，放在src目录下：：

   
       
            
     
                  org.hibernate.dialect.MySQL5Dialect        
             
     
      true
             
     
                  com.mysql.jdbc.Driver        
             
     
                  jdbc:mysql://localhost/test        
             
     
                  root        
             
     
                  jiangyu        
             
         
    
   

用 MySQL来储存数据：

CREATE TABLE `employee` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `first_name` varchar(20) DEFAULT NULL,  `last_name` varchar(20) DEFAULT NULL,  `salary` int(11) DEFAULT NULL,  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

测试类：

package com.ydoing.test;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import com.ydoing.domain.Employee;public class Main {    public static void main(String[] args) {        Configuration conf = new Configuration();        conf.configure();        // ServiceRegistry serviceRegistry = new        // ServiceRegistryBuilder().applySettings(conf.getProperties())        // .buildServiceRegistry();        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(conf.getProperties())                .build();        SessionFactory factory = conf.buildSessionFactory(serviceRegistry);        Session session = factory.openSession();        Employee emp = new Employee();        emp.setFirstName("Mac");        emp.setLastName("Jack");        emp.setSalary(100);        Transaction tx = session.getTransaction();        tx.begin();        session.save(emp);        tx.commit();        session.close();    }}

控制台输出：

Hibernate: insert into EMPLOYEE (first_name, last_name, salary) values (?, ?, ?)

查看MySQL数据