肝 hibernate 配置and增删改查 and 测试

　　已经通宵三天撸代码了,现在的我已经养成晚上修仙写代码的节奏了.....最近刚刚复习到了 hibernate 谈谈这篇文章就谈谈我对这货的理解吧.

在看这篇文章之前希望你知道sessionfactory 和session 还有 transaction(事物) 诶嘿不造的可以去看看http://blog.csdn.net/u012377333/article/details/48086193

　　 OK正题开始步骤我们需要一个可以持久化的bean类还有它的附属映射 hbm.xml文件以及dao(重要) and 测试类

首先开始是bean类代码如下:

package qy.java.bean;

public class Userbean {
    private int id;
    private String username;
    private String password;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    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;
    }

    @Override
    public String toString() {
        return "Userbean{" +
                "id=" + id +
                ", username='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

其次是他的映射文件

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="qy.java.bean">
    <class name="Userbean" table="x_user">
        <id name="id" type="int" column="id">
            <generator class="native"/>
        </id>
        <property name="username" type="string" column="username" length="20"/>
        <property name="password" type="string" column="password" length="20"/>
    </class>
</hibernate-mapping>

这里要说一个在主配置文件里面我没有配置自动建表的那货= = 所以我是直接手动建表有兴趣的同学可以自己去配置

　　然后是dao类里面包括增删改查还有一个记录数是买4送一吧,哦对了我这种初始方法是比较老的一种方法新的初始化方法在下面

package qy.java.dao;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.query.Query;
import qy.java.bean.Userbean;

import java.util.List;


public class Userdao {
    private static SessionFactory sf;
    static {
        Configuration cfg = new Configuration().configure("hibernate.cfg.xml");
        sf = cfg.buildSessionFactory();// 获得会话工厂
    }

    // 增加
    public void add(Userbean user) {
        // 读配置文件，会
        Session s = sf.openSession();
        Transaction t = null;
        try {
            t = s.beginTransaction();
            s.save(user); //持久化 对象
            t.commit(); //提交
        } catch (Exception e) {
            t.rollback(); //回滚
            throw new RuntimeException(e);
        } finally {
            s.close();
        }

    }

    // 更新
    public void update(Userbean user) {
        // 读配置文件，会
        Session s = sf.openSession();
        Transaction t = null;
        try {
            t = s.beginTransaction();
            s.update(user);
            // s.update("username", user);
            t.commit();
        } catch (Exception e) {
            t.rollback();
            throw new RuntimeException(e);
        } finally {
            s.close();
        }

    }
    //删除
    public void delete(int id) {
        // 读配置文件，会
        Session s = sf.openSession();
        Transaction t = null;
        try {
            t = s.beginTransaction();
            // User user = (User) s.get(User.class, id);
            Userbean user = new Userbean();
            user.setId(id);
            s.delete(user);
            t.commit();

        } catch (Exception e) {
            t.rollback();
            throw new RuntimeException(e);
        } finally {
            s.close();
        }
    }
    //查询所有
    public List<Userbean> findALL() {
        // 读配置文件，会
        Session s = sf.openSession();
        List<Userbean> list = null;
        try {

            list = s.createQuery("FROM Userbean").list();
            /*Criteria c = s.createCriteria(User.class);
            list = c.list();*/
        } catch (Exception e) {
            throw e;
        } finally {
            s.close();
        }
        return list;
    }

           // 查询总记录数
    public long findUserCount() {
        //int  double  ，integer Double  char   Charset
        Session s = sf.openSession();
        Long count = null;
        try {
            count  = (Long) s.createQuery("SELECT COUNT(*) FROM Userbean ")//
                    .uniqueResult();

        } catch (Exception e) {
            throw e;
        } finally {
            s.close();
        }
        return count;

    }
}

这个是新的初始化方法

package qy.java.dao;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import qy.java.bean.Userbean;

public class Foxdao {
    private static  SessionFactory sf;
    static {
        try {
            Configuration configuration = new Configuration();
            configuration.configure();
            sf = configuration.buildSessionFactory();
        } catch (Throwable ex) {
            throw new ExceptionInInitializerError(ex);
        }
    }

    // 增加
    public void add(Userbean user) {
        // 读配置文件，会
        Session s = sf.openSession();
        Transaction t = null;
        try {
            t = s.beginTransaction();
            s.save(user); //持久化 对象
            t.commit(); //提交
        } catch (Exception e) {
            t.rollback(); //回滚
            throw new RuntimeException(e);
        } finally {
            s.close();
        }

    }

}

然后了是测试方法= = 仁慈的我还给发测试.....

package test.qy.java.dao; 

import org.junit.Test; 
import org.junit.Before; 
import org.junit.After;
import qy.java.bean.Userbean;
import qy.java.dao.Userdao;

import java.util.Iterator;
import java.util.List;

/** 
* Userdao Tester. 
* 
* @author <Authors name> 
* @since <pre>���� 20, 2017</pre> 
* @version 1.0 
*/ 
public class UserdaoTest { 

@Before
public void before() throws Exception { 
} 

@After
public void after() throws Exception { 
} 

/** 
* 
* Method: add(Userbean user) 
* 
*/ 
@Test
public void testAdd() throws Exception {

    Userbean user = new Userbean();
    user.setPassword("wqerwqer");
    user.setUsername("zhangsan");
        new Userdao().add(user);
} 
@Test
public void updel(){
    Userbean userbean = new Userbean();
        userbean.setId(1);
        userbean.setUsername("滑稽");
        userbean.setPassword("10086");
         new Userdao().update(userbean);
}
@Test
public void delet(){
    new Userdao().delete(2);
}

@Test
    public void file(){
       List<Userbean> list =new Userdao().findALL();
        Iterator<Userbean> it = list.iterator();
            Userbean user = null;
            while (it.hasNext()){
                user = it.next();
                System.out.println(user.getUsername());
            }

    }
@Test
    public void testFindAllUserCount(){
        long count =new Userdao().findUserCount();
            System.out.println(count);
}

}

增删改查虽然简单但是这些都是基础就像功夫里面的蹲马步跑步一样灵活运用才能发挥他们真正的实力相互之间的配合结合自己的所需才能实现作用最大化..

　　emmm写完了刚开始搭建环境的时候出现 hibernate的不兼容我这个 jdk1.7原因是hibernate的版本太高了 = =然后我又懒所以我就去下了一个1.8明明十多分钟能搞定的事情用了一个多小时...气死欧蕾.