DAO泛型
DAO泛型：package com.dao;
import java.io.Serializable;import java.util.List;import com.domain.Attend;import com.utils.Pagination;//泛型的接口/*泛型真正要做的事情就是找到具体的实体类是哪个 * <T>:占位符，代表真正在运行时候的实体类（Employee,Manager,Application....） * <PK>:主键类，必须实现Serializable接口 */public interface GenerateDao<T,PK extends Serializable> {public Integer save(T entity);public void update(T entity);public void delete(T entity);public void delete(PK id);public List<T> findAll();public T get(PK id);//在工具类中定义2个基本方法//1.通过HQL和参数返回一个对象public Object queryObject(final String hql,final Object[] values);//2.通过HQL和参数返回一个Listpublic List query(final String hql,final Object[] values);//3.实现分页的一个公共方法public Pagination<T> getPagination(final String hql,final Object[] values,final int pageNow,final int rowCount,final int pageSize);} 实现以上接口：
package com.dao.impl;
import java.io.Serializable;import java.lang.reflect.ParameterizedType;import java.sql.SQLException;import java.util.List;import org.hibernate.HibernateException;import org.hibernate.Query;import org.hibernate.Session;import org.springframework.orm.hibernate3.HibernateCallback;import org.springframework.orm.hibernate3.support.HibernateDaoSupport;import com.dao.GenerateDao;import com.domain.Attend;import com.utils.Pagination;/* * 泛型DAO的实现 * (1)继承泛型接口 * (2)HiberanteDaoSupport * (3)得到使用这个方法的实体类 * (4)实现具体的数据操作方法 */public class GenerateDaoImpl<T,PK extends Serializable> extends HibernateDaoSupport implements GenerateDao<T, PK>{private final Class<T> clazz;public GenerateDaoImpl(){//通过java反射机制，得到在运行时的具体的实体类clazz = (Class<T>)((ParameterizedType)getClass().getGenericSuperclass()).getActualTypeArguments();}public void delete(T entity) {this.getHibernateTemplate().delete(entity);}public void delete(PK id) {this.getHibernateTemplate().delete(get(id));}public List<T> findAll() {return this.getHibernateTemplate().find("from "+clazz.getName());}public Integer save(T entity) {return (Integer)this.getHibernateTemplate().save(entity);}public void update(T entity) {this.getHibernateTemplate().update(entity);}public T get(PK id) {return this.getHibernateTemplate().get(clazz, id);}public List query(final String hql, final Object[] values) {return this.getHibernateTemplate().executeFind(new HibernateCallback() {public Object doInHibernate(Session arg0)throws HibernateException, SQLException {Query q = arg0.createQuery(hql);if(values != null){for(int i=0;i<values.length;i++){q.setParameter(i, values);}}return q.list();}});}public Object queryObject(final String hql, final Object[] values) {return this.getHibernateTemplate().execute(new HibernateCallback() {public Object doInHibernate(Session arg0)throws HibernateException, SQLException {Query q = arg0.createQuery(hql);if(values != null){for(int i=0;i<values.length;i++){q.setParameter(i, values);}}return q.list();}});}public Pagination<T> getPagination(final String hql, final Object[] values,final int pageNow, final int rowCount, final int pageSize) {return (Pagination<T>) this.getHibernateTemplate().execute(new HibernateCallback() {public Object doInHibernate(Session arg0)throws HibernateException, SQLException {Pagination pagination = new Pagination<T>(pageSize, pageNow, rowCount);Query q = arg0.createQuery(hql);if(values != null){for(int i=0;i<values.length;i++){q.setParameter(i, values);}}q.setFirstResult(pageSize*(pageNow-1));q.setMaxResults(pageSize);List list = q.list();pagination.setPageList(list);return pagination;}});}}
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