com.music.dao.impl.GenericDAOImpl.java Source code

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Here is the source code for com.music.dao.impl.GenericDAOImpl.java

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package com.music.dao.impl;

import com.music.dao.GenericDAO;
import java.io.Serializable;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.GenericTypeResolver;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

/**
 *
 * @author HuanPMSE61860
 * @param <K>
 */
public class GenericDAOImpl<K extends Serializable, E> implements GenericDAO<K, E> {

    /**
     * Autowired session factory
     */
    @Autowired
    SessionFactory sessionFactory;

    /**
     * @return Class object of E
     */
    @SuppressWarnings("unchecked")
    private Class<E> getGenericType() {
        // Resolve type of arguments (K,E)
        Class<?>[] typeArgs = GenericTypeResolver.resolveTypeArguments(this.getClass(), GenericDAO.class);
        // Return Class object of E
        return (Class<E>) typeArgs[1];
    }

    /*
    * (non-Javadoc)
    * 
    * @see com.spring.dao.GenericDAO#find()
     */
    @SuppressWarnings({ "unchecked", "deprecation" })
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public List<E> find() {
        // Get current session
        Session session = sessionFactory.getCurrentSession();
        Criteria criteria = session.createCriteria(this.getGenericType());
        return (List<E>) criteria.list();
    }

    /*
    * (non-Javadoc)
    * 
    * @see com.spring.dao.GenericDAO#findById(java.io.Serializable)
     */
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public E findById(K k) {
        // Get current session
        Session session = sessionFactory.getCurrentSession();
        // Get result from session by key
        E result = (E) session.get(this.getGenericType(), k);
        return result;
    }

    /*
    * (non-Javadoc)
    * 
    * @see com.spring.dao.GenericDAO#add(java.lang.Object)
     */
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public boolean add(E e) {
        // Get current session
        if (e != null) {
            Session session = sessionFactory.getCurrentSession();
            // Save e to session
            session.save(e);
            return true;
        }
        return false;
    }

    /*
    * (non-Javadoc)
    * 
    * @see com.spring.dao.GenericDAO#update(java.lang.Object)
     */
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public boolean update(E e) {
        // If e is not null, continue updating e
        if (e != null) {
            // Get current session
            Session session = sessionFactory.getCurrentSession();
            // Update (or merge to existing) e to session
            session.merge(e);
            return true;
        }
        return false;
    }

    /*
    * (non-Javadoc)
    * 
    * @see com.spring.dao.GenericDAO#delete(java.lang.Object)
     */
    @Transactional(propagation = Propagation.REQUIRES_NEW)
    public boolean delete(E e) {
        // If e is not null, continue removing e
        if (e != null) {
            // Get current session
            Session session = sessionFactory.getCurrentSession();
            // Delete e from session
            session.delete(e);
            return true;
        }
        return false;
    }
}