java的SSH的baseDao,巧用泛型

BaseDao接口:

import java.util.List;
public interface BaseDao<T,PK> {

    public void add(T t);
    
    public void upd(T t);
    
    public void del(PK id);
    
    public T getById(PK id);
    
    public List<T> getAll();

    public List<Track> getByAid(String activityId);
    
    
    
}

BaseDaoImple:

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

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.orm.hibernate5.HibernateTemplate;

public class BaseDaoImple<T, PK> implements BaseDao<T, PK> {
    // 保存当前类处理的实体类型对象类型
    private Class clazz;

    public BaseDaoImple() {

        Type clas = this.getClass().getGenericSuperclass();

        ParameterizedType pt = (ParameterizedType) clas;

        Type[] ts = pt.getActualTypeArguments();

        // 获取第一个泛型类型
        clazz = (Class) ts[0];
    }

    @Autowired
    private HibernateTemplate hibernateTemplate;

    @Override
    public void add(T t) {

        hibernateTemplate.save(t);

    }

    @Override
    public void upd(T t) {
        hibernateTemplate.update(t);

    }

    @Override
    public void del(PK id) {
        hibernateTemplate.delete(this.getById(id));
    }

    @Override
    public T getById(PK id) {

        return (T) hibernateTemplate.get(clazz, (Serializable) id);
    }

    @Override
    public List<T> getAll() {
        return hibernateTemplate.loadAll(clazz);
    }

    @Override
    public List<Track> getByAid(String activityId) {

        String queryString = "from Track where activity.activityId = ?";

        return (List<Track>) hibernateTemplate.find(queryString, activityId);

    }

}