Cody_Yu 通用的DAO查询，常见方法集合

import java.io.*;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;

 

import org.hibernate.Hibernate;

import org.hibernate.HibernateException;

import org.hibernate.Query;

import org.hibernate.SQLQuery;

import org.hibernate.Session;

import org.hibernate.Transaction;

import org.hibernate.type.Type;

import org.springframework.orm.hibernate3.HibernateCallback;

import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

 

public class GenericDao extendsHibernateDaoSupport{

    privateThreadLocal<Session> sessions = newThreadLocal<Session>();

    privateThreadLocal<Transaction> transactions = newThreadLocal<Transaction>();

    publicsynchronized Session getMySession(){

        Session session = sessions.get();

        if(session==null){

            session = getSession();

            transactions.set(session.beginTransaction());

            sessions.set(session);

        }else

        if(!session.isOpen()){

            session = getSession();

            transactions.set(session.beginTransaction());

            sessions.set(session);

        }

        returnsession;

    }

    publicsynchronized voidcommitMySession(){

        Session session = sessions.get();

        if(session!=null&&session.isOpen()){

            transactions.get().commit();

            session.close();

        }

        transactions.remove();

        sessions.remove();

    }

    publicsynchronized voidrollbackMySession(){

        Session session = sessions.get();

        if(session!=null&&session.isOpen()){

            transactions.get().rollback();

            session.close();

        }

        transactions.remove();

        sessions.remove();

    }

    public<T> T get(Class<T> clazz, Serializable id){

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

    }

    public<T> T load(Class<T> clazz, Serializable id){

        return(T)getHibernateTemplate().load(clazz, id);

    }

    public<T> void save(T entity){

//        System.out.println("---->gdao.save("+entity.getClass().getName()+")----");

        getHibernateTemplate().save(entity);

    }

    public<T> void update(T entity){

        getHibernateTemplate().update(entity);

    }

    public<T> void delete(T entity){

        getHibernateTemplate().delete(entity);

    }

    

    publicint execUpdateSQL(String sql, Serializable...values){

        Session sess = getMySession();

        SQLQuery query = sess.createSQLQuery(sql);

        if(values!=null&&values.length>0){

            for(inti=0; i<values.length; i++){

                query.setParameter(i, values[i]);

            }

        }

        returnquery.executeUpdate();

    }

    publicLong getFirstLong(String sql, finalSerializable... values) throwsException{

        List<String> params =new ArrayList<String>(1);

        List<Type> types =new ArrayList<Type>(1);

        params.add("c"); types.add(Hibernate.INTEGER);

        Object obj = findUnique(sql, params, types, values);

        if(obj==null){

            return-1L;

        }

        if(objinstanceof Object[]){

            obj = ((Object[])obj)[0];

        }

        if(objinstanceof Number){

            return((Number)obj).longValue();

        }

        return-1L;

    }

//    public Long getFirstLong(String sql,  List<String>params, List<Type>types) throws Exception{

//        Object[] obj = findUnique(sql, params, types);

//        if(obj==null||obj.length==0){

//            return -1L;

//        }

//        Object object = obj[0];

//        if(object instanceof Number){

//            return ((Number)object).longValue();

//        }

//        return -1L;

//    }

    publicList<?> find(String hql){

        returngetHibernateTemplate().find(hql);

    }

//    public List<?> find(String hql, final Object...values){

//        logger.info(hql);

//        return getHibernateTemplate().find(hql, values);

//    }

    

    public<T> List<T> findByPage(Class<T> clazz, finalint start, finalint limit, finalString where, finalSerializable... values){

        String hql ="from " + clazz.getName() +" as e";

        if(where!=null&&where.length()>0){

            hql +=" where " + where;

        }

        finalString fHql = hql;

        returngetHibernateTemplate().executeFind(newHibernateCallback(){

 

            publicObject doInHibernate(Session session)

                    throwsHibernateException, SQLException {

                Query q = session.createQuery(fHql);

                if(values!=null&&values.length>0){

                    for(inti=0; i<values.length; i++){

                        q.setParameter(i, values[i]);

                    }

                }

                q.setFirstResult(start).setMaxResults(limit);

                returnq.list();

            }

            

        });

    }

    public<T> List<T> find(Class<T> clazz, finalString where, finalSerializable... values){

        String hql ="from " + clazz.getSimpleName()+" as e";

        if(where!=null&&where.length()>0){

            hql +=" where " + where;

        }

        returngetHibernateTemplate().find(hql, values);

    }

    publiclong getTotalCountByHql(Class<?> clazz,final String where,final Serializable... values)throws Exception {

        String hql ="select count(*) from " + clazz.getSimpleName()+" as e";

        if(where!=null&&where.length()>0){

            hql +=" where " + where;

        }

        List<Number> cs = getHibernateTemplate().find(hql, values);

        if(cs!=null&&cs.size()>0){

            Number n = cs.get(0);

            returnn.longValue();

        }

        return0;

    }

    publiclong getTotalCount(Class<?> clazz,final String where,final Serializable... values)throws Exception {

        String sql ="select count(1) as c from " + clazz.getSimpleName() + " e";

        if(where!=null&&where.length()>0){

            sql +=" where " + where;

        }

        returngetFirstLong(sql, values);

    }

    

    publiclong getTotalCount(String sql,final Serializable... values)throws Exception {

        returngetFirstLong(sql, values).longValue();

    }

    publicObject[] findUnique(finalString sql,  List<String>params, List<Type>types, final Serializable...values) {

        Session sess = getMySession();

        logger.debug("------findUnique.getSession()! sess="+sess.hashCode());

        SQLQuery query = sess.createSQLQuery(sql);

        for(intj=0; j<params.size(); j++){

            query.addScalar(params.get(j), types.get(j));

        }

        if(values!=null&&values.length>0){

            for(inti=0; i<values.length; i++){

                query.setParameter(i, values[i]);

            }

        }

        query.setMaxResults(1);

        List<?> list = query.list();

        if(list==null||list.size()==0){

            returnnull;

        }

        Object obj = list.get(0);

        if(obj==null){

            returnnull;

        }

        logger.debug("obj.type="+obj.getClass().getName());

        if(!obj.getClass().isArray()){//如果返回值不是数组，则要进行相关的处理

            if(objinstanceof Number){

                if(objinstanceof Long){

                    returnnew Long[]{(Long)(obj)};

                }

                if(objinstanceof Integer){

                    returnnew Long[]{newLong((Integer)obj)};

                }

                returnnew Number[]{(Number)obj};

            }

            returnnew Object[]{obj};

        }

        return(Object[])obj;

    }

    publicList<Object[]> find(finalString sql, List<String>params, List<Type>types, final Serializable... values) {

        Session sess = getMySession();

        logger.debug("------find.getSession()! sess="+sess.hashCode());

        SQLQuery query = sess.createSQLQuery(sql);

        

        for(intj=0; j<params.size(); j++){

            query.addScalar(params.get(j), types.get(j));

        }

        if(values!=null&&values.length>0){

            for(inti=0; i<values.length; i++){

                query.setParameter(i, values[i]);

            }

        }

        returnquery.list();

    }

    publiclong getNextId(String sequence)throws Exception{

        String sql ="select "+sequence+".nextval as nextid from dual";

 

        Session sess = getMySession();

        logger.debug("------generateId.getSession()! sess="+sess.hashCode());

        SQLQuery query = sess.createSQLQuery(sql);

        query.addScalar("nextid", Hibernate.LONG);

        List<?> list = query.list();

        if(list==null||list.size()==0){

            return-1L;

        }

        Object obj = list.get(0);

        logger.debug("obj.type="+obj.getClass().getName());

        if(objinstanceof Number){

            return((Number)obj).longValue();

        }

        return-1L;

    }

    publicboolean exists(String sql,final Object...values)throws Exception{

        Session sess = getMySession();

        logger.debug("------exists.getSession()! sess="+sess.hashCode());

        SQLQuery query = sess.createSQLQuery(sql);

        for(inti=0; i<values.length; i++){

            query.setParameter(i, values[i]);

        }

        List<?> list = query.list();

        if(list==null||list.size()==0){

            returnfalse;

        }

        returntrue;

    }

 

}