Hibernate简略的BaseDao

Hibernate简单的BaseDao

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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);}

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?接口实现类：

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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;}}

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下面是调用方式：

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package com.xiva.hibernate.dao;import com.xiva.hibernate.domain.Person;public interface PersonDao extends BaseDao<Person, Long>{}

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package com.xiva.hibernate.dao;import com.xiva.hibernate.domain.Person;public class PersonDaoImpl extends BaseDaoImpl<Person, Long> implements PersonDao {}

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实体类：

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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;}}

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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，

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

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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。

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