newsdao.java

用ssh框架下开发的一个简单的新闻发布系统

package org.imm.dao.hibernate;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.imm.dao.INewsDAO;
import org.imm.model.News;
import org.springframework.context.ApplicationContext;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

public class NewsDAO extends HibernateDaoSupport implements INewsDAO {

    private static final Log log = LogFactory.getLog(NewsDAO.class);

	//property constants
	public static final String TITLE = "title";
	public static final String CONTENT = "content";

	protected void initDao() {
		//do nothing
	}
    
    /* (non-Javadoc)
	 * @see org.imm.dao.hibernate.INewsDAO#save(org.imm.model.News)
	 */
    public void save(News transientInstance) {
        log.debug("saving News instance");
        try {
            getHibernateTemplate().saveOrUpdate(transientInstance);
            log.debug("save successful");
        } catch (RuntimeException re) {
            log.error("save failed", re);
            throw re;
        }
    }
    
	/* (non-Javadoc)
	 * @see org.imm.dao.hibernate.INewsDAO#delete(org.imm.model.News)
	 */
	public void delete(News persistentInstance) {
        log.debug("deleting News instance");
        try {
            getHibernateTemplate().delete(persistentInstance);
            log.debug("delete successful");
        } catch (RuntimeException re) {
            log.error("delete failed", re);
            throw re;
        }
    }
    
    /* (non-Javadoc)
	 * @see org.imm.dao.hibernate.INewsDAO#findById(java.lang.Integer)
	 */
    public News findById( java.lang.Integer id) {
        log.debug("getting News instance with id: " + id);
        try {
            News instance = (News) getHibernateTemplate()
                    .get("org.imm.model.News", id);
            return instance;
        } catch (RuntimeException re) {
            log.error("get failed", re);
            throw re;
        }
    }
    
    
    /* (non-Javadoc)
	 * @see org.imm.dao.hibernate.INewsDAO#findByExample(org.imm.model.News)
	 */
    public List findByExample(News instance) {
        log.debug("finding News instance by example");
        try {
            List results = getHibernateTemplate().findByExample(instance);
            log.debug("find by example successful, result size: " + results.size());
            return results;
        } catch (RuntimeException re) {
            log.error("find by example failed", re);
            throw re;
        }
    }    
    
    public List findByProperty(String propertyName, Object value) {
      log.debug("finding News instance with property: " + propertyName
            + ", value: " + value);
      try {
         String queryString = "from News as model where model." 
         						+ propertyName + "= ?";
		 return getHibernateTemplate().find(queryString, value);
      } catch (RuntimeException re) {
         log.error("find by property name failed", re);
         throw re;
      }
	}

	public List findByTitle(Object title) {
		return findByProperty(TITLE, title);
	}
	
	public List findByContent(Object content) {
		return findByProperty(CONTENT, content);
	}
	
    public News merge(News detachedInstance) {
        log.debug("merging News instance");
        try {
            News result = (News) getHibernateTemplate()
                    .merge(detachedInstance);
            log.debug("merge successful");
            return result;
        } catch (RuntimeException re) {
            log.error("merge failed", re);
            throw re;
        }
    }

    public void attachDirty(News instance) {
        log.debug("attaching dirty News instance");
        try {
            getHibernateTemplate().saveOrUpdate(instance);
            log.debug("attach successful");
        } catch (RuntimeException re) {
            log.error("attach failed", re);
            throw re;
        }
    }
    
    public void attachClean(News instance) {
        log.debug("attaching clean News instance");
        try {
            getHibernateTemplate().lock(instance, LockMode.NONE);
            log.debug("attach successful");
        } catch (RuntimeException re) {
            log.error("attach failed", re);
            throw re;
        }
    }

	public static INewsDAO getFromApplicationContext(ApplicationContext ctx) {
    	return (INewsDAO) ctx.getBean("NewsDAO");
	}
	
	//////////////////////////////////////////////////////
	
	public void saveOrUpdate(News news,Integer id){
		String queryString = "insert into News(newid,title,content) values("+"'news.getNewid()'"+"'news.getTitle()'"+"'news.getContent()'"+"where newid=?"+"'id'";
		getHibernateTemplate().save(news,queryString);
	}
}