Hibernate Dao映射配置通用接口类反射获取加载calass实例

Posted 2021-01-09 hirampeng

接口：

package com.ph.dao;

import java.io.Serializable;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;

public interface BaseDao<T> {

public void save(T t);

public void delete(T t);

public void update(T t);

public T findById(Serializable id);

public List<T>  findAll();

public Integer findCount(DetachedCriteria detachedCriteria);

public List<T> findByPage(DetachedCriteria detachedCriteria,Integer begin,Integer pageSize);

}

 

接口实现类：

package com.ph.dao.impl;

import java.io.Serializable;

import java.lang.reflect.ParameterizedType;

import java.lang.reflect.Type;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;

import org.hibernate.criterion.Projections;

import org.springframework.orm.hibernate5.support.HibernateDaoSupport;

import com.ph.dao.BaseDao;

public class BaseDaoImpl<T> extends HibernateDaoSupport implements BaseDao<T> {

private Class clazz;

public BaseDaoImpl() {

//获取子类

Class clazz = this.getClass();

//反射加载父类,获取参数化类型

Type type = clazz.getGenericSuperclass();

//获取实际类型参数

ParameterizedType pType = (ParameterizedType) type;

Type[] types = pType.getActualTypeArguments();

//设置clazz

this.clazz = (Class) types[0];

}

public void save(T t) {

this.getHibernateTemplate().save(t);

}

public void delete(T t) {

this.getHibernateTemplate().delete(t);

}

public void update(T t) {

this.getHibernateTemplate().update(t);

}

public T findById(Serializable id) {

return (T) this.getHibernateTemplate().get(clazz, id);

}

public List<T>  findAll() {

return (List<T>) this.getHibernateTemplate().find("from "+clazz.getSimpleName());

}

public Integer findCount(DetachedCriteria detachedCriteria) {

detachedCriteria.setProjection(Projections.rowCount());

List<Long> list = (List<Long>) this.getHibernateTemplate().findByCriteria(detachedCriteria);

if (list.size()>0) {

return list.get(0).intValue();

}

return 0;

}

public List<T> findByPage(DetachedCriteria detachedCriteria,Integer begin,Integer pageSize) {

detachedCriteria.setProjection(null);

return (List<T>) this.getHibernateTemplate().findByCriteria(detachedCriteria, begin, pageSize);

}

}