MyEclipse中hibernate反向工程实例(一对多关联).doc

MyEclipse中hibernate反向工程实例（一对多关联）1、数据库设计实例对象为工作人员和部门，关系为一个部门对应多个工作人员，一个工作人员只属于一个部门见表语句如下：（先用Navicat建的表，然后导出的sql语句），数据库名称为testSET FOREIGN_KEY_CHECKS=0;DROP TABLE IF EXISTS t_department;CREATE TABLE t_department ( id int(11) NOT NULL auto_increment, departmentname varchar(40) NOT NULL, departmentlocation varchar(100) NOT NULL, PRIMARY KEY (id) ENGINE=InnoDB DEFAULT CHARSET=utf8;DROP TABLE IF EXISTS t_user;CREATE TABLE t_user ( id int(11) NOT NULL auto_increment, username varchar(20) NOT NULL, password varchar(20) NOT NULL, departmentid int(11) NOT NULL, PRIMARY KEY (id), KEY departmentid (departmentid), CONSTRAINT departmentid FOREIGN KEY (departmentid) REFERENCES t_department (id) ENGINE=InnoDB DEFAULT CHARSET=utf8;2、使用MyEclipse反向工程生成配置文件和POJO类第一步：配置数据源1、打开MyEclipse，新建一个web工程，这里命名为hibernate_demo2、打开数据库设置器：依次单击【window】-【Show View】-【Other】 如下图所示：3、在弹出的窗口ShowView中选择DB Browser,如下图所示:4、在DB Browser窗口中，选择显示的图标，单击右键执行新建命令，如下图示5、弹出Database Driver对话框，在此会要求我们配置数据库的相关信息，具体设置如下图所示，设置完成，单击Finish.【第二步】引入hibernate配置文件1、 添加hibernate包：选中我们的Web工程，依次单击鼠标右键-MyEclipse-Add Hibernate Capabilities 如下图所示：2、 在弹出的窗口中做如下设置：【Next】，创建hibernate的配置文件【Next】，指明hibernate与数据库的连接【Next】，创建HibernateSessionFactory类，用来获得session 。如果前面没有设置包名，要先单击New创建新的包。单击【Finish】按钮，页面效果如下图所示：接下来要给hibernate.cfg.xml文件添加属性：在properties处选择Add，如下图所示：单击【Add】，在Hibernate Properties Wizard页面填入如下图所示信息，最后单击Ok。show_sql：默认为false，如果为true，表示在程序运行时，会在控制台输出SQL语句，这有利于跟中Hibernate的运行状态。在开发和测试阶段，可以将该属性设置为true，以便跟踪、调试程序，在应用发布以后 ，应将该属性值设置为false，以减少应用的输出信息，提高运行性能。【第三步】添加hibernate映射文件和POJO类1、新建com.lqh.beans包2、在前面设置的数据源上找到我们要操作的表：在DB Browser中选中新建的数据源，单击鼠标右键并选择open connection.输入数据库的用户名和密码，以创建连接：找到刚才新建的test数据库，然后是TABLE，如下图所示：生成POJO：点击Next，配置映射类型（暂时未用到）点击Next，配置反向工程细节点击Finish，即可完成，生成的映射文件以及POJO类如下：User.javapackage com.lqh.beans;/* * User entity. author MyEclipse Persistence Tools */public class User implements java.io.Serializable / Fieldsprivate Integer id;private Department department;private String username;private String password;/ Constructors/* default constructor */public User() /* full constructor */public User(Department department, String username, String password) this.department = department;this.username = username;this.password = password;/ Property accessorspublic Integer getId() return this.id;public void setId(Integer id) this.id = id;public Department getDepartment() return this.department;public void setDepartment(Department department) this.department = department;public String getUsername() return this.username;public void setUsername(String username) this.username = username;public String getPassword() return this.password;public void setPassword(String password) this.password = password;Department.javapackage com.lqh.beans;import java.util.HashSet;import java.util.Set;/* * Department entity. author MyEclipse Persistence Tools */public class Department implements java.io.Serializable / Fieldsprivate Integer id;private String departmentname;private String departmentlocation;private Set users = new HashSet(0);/ Constructors/* default constructor */public Department() /* minimal constructor */public Department(String departmentname, String departmentlocation) this.departmentname = departmentname;this.departmentlocation = departmentlocation;/* full constructor */public Department(String departmentname, String departmentlocation,Set users) this.departmentname = departmentname;this.departmentlocation = departmentlocation;this.users = users;/ Property accessorspublic Integer getId() return this.id;public void setId(Integer id) this.id = id;public String getDepartmentname() return this.departmentname;public void setDepartmentname(String departmentname) this.departmentname = departmentname;public String getDepartmentlocation() return this.departmentlocation;public void setDepartmentlocation(String departmentlocation) this.departmentlocation = departmentlocation;public Set getUsers() return this.users;public void setUsers(Set users) this.users = users;编写测试类代码，如下：package com.lqh.test;import org.hibernate.Session;import org.junit.Test;import com.lqh.beans.Department;import com.lqh.beans.User;import com.lqh.utils.HibernateSessionFactory;public class HibernateTest /* * 测试保存部门 */Testpublic void testSaveDepartment() Department department = new Department();department.setDepartmentlocation(清河小营东路);department.setDepartmentname(北京信息科技);Session session = HibernateSessionFactory.getSession();session.beginTransaction();session.save(department);session.getTransaction().commit();session.close();/* * 测试保存用户，该用户已存在对应Department */Testpublic void testSavaUser() Session session = HibernateSessionFactory.getSession();session.beginTransaction();Department department = (Department) session.load(Department.class, 1);User user = new User();user.setUsername(hehe);user.setPassword(123455);user.setDepartment(department);session.save(user);session.getTransaction().commit();session.close();/* * 测试保存用户，该用户对应的Department未存在数据库中* 此处注意，要将User.hbm.xml中的cascade设为all */Testpublic void testSaveUserAndDepartment() Session session = HibernateSessionFactory.getSession();session.beginTransaction();Department department = new Dep