Dao設計模型，dao模型

Dao設計模型，dao模型

一、目錄的工程結構

　　

二、模型設計

　　

 

三、核心代碼的實現

　　1、實體類

package com.lyh.domain;public class Book {    private String id;    private String name;    private float price;    public String getId() {        return id;    }    public void setId(String id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public float getPrice() {        return price;    }    public void setPrice(float price) {        this.price = price;    }}package com.lyh.domain;public class Customer {    private Integer id;    private String name;    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

　　2、Dao設計

最頂層Dao.javapackage com.lyh.dao;import java.io.Serializable;public interface Dao<T> {    void add(T t);    void update(T t);    void delete(Serializable id);    T findOne(Serializable id);}//BookDao.javapackage com.lyh.dao;import com.lyh.domain.Book;public interface BookDao extends Dao<Book>{    }//CustomerDao.java package com.lyh.dao;import java.util.List;import com.lyh.domain.Customer;public interface CustomerDao extends Dao<Customer>{        List<Customer> findCustomers(int startIndex,int offset);}

　　3、具體Dao的實作類別

　　

Dao實作類別BaseDao.javapackage com.itheima.dao.impl;import java.io.Serializable;import java.lang.reflect.ParameterizedType;import java.lang.reflect.Type;import org.hibernate.Session;import org.hibernate.Transaction;import com.itheima.dao.Dao;import com.itheima.util.HibernateUtil;public abstract class BaseDao<T> implements Dao<T> {        private Class clazz;    public BaseDao() {        //知道子類到底操作的是什麼類型的javabean。即給clazz賦值        Type type = this.getClass().getGenericSuperclass();  //new BookDaoImpl() 得到 BaseDao<Book> 參數化的泛型類        ParameterizedType ptype = (ParameterizedType)type;    // 強轉成  BaseDao<Book>        Type types[] = ptype.getActualTypeArguments();        clazz = (Class) types[0];        System.out.println(clazz);    }        @Override    public void add(T t) {        Session session = HibernateUtil.getSession();        Transaction tx = session.beginTransaction();        session.save(t);        tx.commit();        session.close();            }    @Override    public void update(T t) {        Session session = HibernateUtil.getSession();        Transaction tx = session.beginTransaction();        session.update(t);        tx.commit();        session.close();    }    @Override    public void delete(Serializable id) {        Session session = HibernateUtil.getSession();        T bean = findOne(id);        Transaction tx = session.beginTransaction();        session.delete(bean);        tx.commit();        session.close();    }    @Override    public T findOne(Serializable id) {        Session session = HibernateUtil.getSession();        return (T) session.get(clazz, id);    }}//BookDaoImpl package com.lyh.dao.impl;import com.lyh.dao.BookDao;import com.lyh.domain.Book;public class BookDaoImpl extends BaseDao<Book> implements BookDao {    }//CustomerDaoImpl.javapackage com.lyh.dao.impl;import java.util.List;import com.lyh.dao.CustomerDao;import com.lyh.domain.Customer;public class CustomerDaoImpl extends BaseDao<Customer> implements CustomerDao {    //    public CustomerDaoImpl(){//        super(Customer.class);//    }        public List<Customer> findCustomers(int startIndex, int offset) {            return null;    }}