Hibernate简单的BaseDao

package com.xiva.hibernate.dao;

import java.io.Serializable;


public interface BaseDao<E extends Serializable, PK extends Serializable> {

	/**
	 * 插入一个对象
	 * @param person
	 */
	public void insert(E entity);
	
	/**
	 * 删除一个对象
	 * @param object
	 */
	public void delete(E entity);
	
	
	/**
	 * 根据主键，使用到Criteria接口查询
	 * @param id
	 * @return
	 */
	public E getByPK(PK id);
	
	/**
	 * 直接使用session的get方法
	 * @param id
	 * @return
	 */
	public E getById(PK id);
	
	/**
	 * 更新一个对象
	 * @param person
	 */
	public void update(E entity);
	
}

 接口实现类：

package com.xiva.hibernate.dao;

import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.criterion.Restrictions;

import com.xiva.hibernate.HibernateUtil;

public  class BaseDaoImpl<E extends Serializable, PK extends Serializable> implements BaseDao<E, PK>  {
	
	
	private Class<?> entityClass;
	
	public BaseDaoImpl(){
		Class<?> c = this.getClass();  
        Type type = c.getGenericSuperclass();  
        if (type instanceof ParameterizedType) {  
            this.entityClass = (Class<?>) ((ParameterizedType) type)  
                    .getActualTypeArguments()[0];  
        }  
	}

	/**
	 * 插入数据库同样需要使用到事务
	 */
	public void insert(E entity) {
		Session session = null;
		Transaction tx = null;
		try{
			session = HibernateUtil.getSession();
			tx = session.beginTransaction();
			session.save(entity);
			tx.commit();
		}finally{
			if(session!=null){
				session.close();
			}
		}

	}

	/**
	 * 删除一个对象与查询不同必须使用事务提交
	 */
	public void delete(E entity) {
		Session session = null;
		Transaction tx = null;
		try{
			session = HibernateUtil.getSession();
			tx = session.beginTransaction();
			session.delete(entity);
			tx.commit();
		}finally{
			if(session!=null){
				session.close();
			}
		}
	}


	@SuppressWarnings("unchecked")
	public E getByPK(PK id) {
		Session session = null;
		E entity = null;
		try {
			session = HibernateUtil.getSession();
			Criteria criteria = session.createCriteria(this.entityClass);
			criteria.add(Restrictions.eq("id", id));
			// List<Person> list = criteria.list();
			// if(list.size()!=0)
			// person = list.get(0);
			entity = (E) criteria.uniqueResult();
//			if(person!=null)
//				System.out.println(person.getDepartment().getDepartmentName());
		} finally {
			if(session!=null){
				session.close();
			}
		}
		return entity;
	}


	public void update(E entity) {
		
		Session session = null;
		Transaction tx = null;
		try{
			session = HibernateUtil.getSession();
			tx = session.beginTransaction();
			session.update(entity);
			tx.commit();
		}finally{
			if(session!=null){
				session.close();
			}
		}

	}


	@SuppressWarnings("unchecked")
	public E getById(PK id) {
		Session session = null;
		E entity = null;
		try {
			session = HibernateUtil.getSession();
			entity = (E) session.get(this.entityClass, id);
//			Hibernate.initialize(person.getDepartment());
		} finally {
			if(session!=null){
				session.close();
			}
		}
		return entity;
	}
}

下面是调用方式：

package com.xiva.hibernate.dao;

import com.xiva.hibernate.domain.Person;

public interface PersonDao extends BaseDao<Person, Long>{

}

 

package com.xiva.hibernate.dao;

import com.xiva.hibernate.domain.Person;

public class PersonDaoImpl extends BaseDaoImpl<Person, Long> implements PersonDao {
	
}

实体类：

package com.xiva.hibernate.domain;

import java.io.Serializable;
import java.util.Date;

public class Person implements Serializable{
	
	
	/**
	 * 
	 */
	private static final long serialVersionUID = -6190737414531892695L;
	private Long id;
	private String name;
	private String password;
	private Date birthday;
	private Department department;
	private IdCard idCard;
	private Address address;
	

	public Person() {
	}

	public Person(Long id, String name, String password, Department department,
			IdCard idCard, Date birthday, Address address) {
		this.id = id;
		this.name = name;
		this.password = password;
		this.department = department;
		this.idCard = idCard;
		this.birthday = birthday;
		this.address = address;
	}

	public Long getId() {
		return id;
	}

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

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public Department getDepartment() {
		return department;
	}

	public void setDepartment(Department department) {
		this.department = department;
	}

	public IdCard getIdCard() {
		return idCard;
	}

	public void setIdCard(IdCard idCard) {
		this.idCard = idCard;
	}

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public Address getAddress() {
		return address;
	}

	public void setAddress(Address address) {
		this.address = address;
	}
	
}

主要是需要实现Serializable接口。还有在实现类初始化的时候，需要知道是哪一个类，

public BaseDaoImpl(){
		Class<?> c = this.getClass();  
        Type type = c.getGenericSuperclass();  
        if (type instanceof ParameterizedType) {  
            this.entityClass = (Class<?>) ((ParameterizedType) type)  
                    .getActualTypeArguments()[0];  
        }  
	}

也许上面的方法是实现了基本的Dao，但是不可取，这个只是使用hibernate框架，我们的事务只能在Dao层进行控制，而一般的数据回滚，我们是在业务逻辑层来做的；因此可能结合Spring来实现这样的功能比较简单，以后贴出例子。