spring+hibernate+c标签分页+mysql

package com.th.dao.hibernate; import java.io.Serializable; import java.lang.reflect.Field; import java.sql.SQLException; import java.util.ArrayList; import java.util.Collections; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.hibernate.Criteria; import org.hibernate.HibernateException; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.criterion.DetachedCriteria; import org.hibernate.criterion.Projections; import org.springframework.dao.DataRetrievalFailureException; import org.springframework.orm.hibernate3.HibernateCallback; import org.springframework.orm.hibernate3.HibernateTemplate; import com.th.domain.Page; /** * This base class is prepared for subclass to do CRUD easily. * * @author tianheng */ public abstract class GenericHibernateDao<T> { protected static final Object[] EMPTY_OBJECT_ARRAY = new Object[] {}; protected Log log = LogFactory.getLog(getClass()); private final Class<T> clazz; protected HibernateTemplate hibernateTemplate; /** * Inject domain's class type in constructor. * * @param clazz Domain's class. */ public GenericHibernateDao(Class<T> clazz) { this.clazz = clazz; } /** * @spring.property name="hibernateTemplate" ref="hibernateTemplate" */ public void setHibernateTemplate(HibernateTemplate hibernateTemplate) { this.hibernateTemplate = hibernateTemplate; } @SuppressWarnings("unchecked") public T query(Serializable id) { T t = (T)hibernateTemplate.get(clazz, id); if(t==null) throw new DataRetrievalFailureException("Object not found."); // it is strange that load() method return a lazy-loading proxy object // and it may cause LazyInitializationException! return t; } /** * Default implementation of creating new domain object. */ public void create(T t) { hibernateTemplate.save(t); } /** * Default implementation of deleting new domain object. */ public void delete(T t) { hibernateTemplate.delete(t); } /** * Default implementation of updating domain object. */ public void update(T t) { hibernateTemplate.update(t); } /** * Do an update hql query, return the affected rows. * * @param updateHql Update HQL. * @param values Parameters or null if none. * @return The affected rows. */ protected int executeUpdate(final String updateHql, final Object[] values) { HibernateCallback updateCallback = new HibernateCallback() { public Object doInHibernate(Session session) throws HibernateException, SQLException { Query query = session.createQuery(updateHql); if(values!=null) { for(int i=0; i<values.length; i++) query.setParameter(i, values[i]); } return new Integer(query.executeUpdate()); } }; return ((Integer)hibernateTemplate.execute(updateCallback)).intValue(); } /** * Prepared for sub-class for convenience. Query for list and also return * total results' number. * * @param selectCount HQL for "select count(*) from ..." and should return a Long. * @param select HQL for "select * from ..." and should return object list. * @param values For prepared statements. * @param page Page object for store page information. */ protected List queryForList(final String selectCount, final String select, final Object[] values, final Page page) { Integer count = (Integer)queryForObject(selectCount, values); page.setTotalCount(count.intValue()); if(page.isEmpty()) return Collections.EMPTY_LIST; return queryForList(select, values, page); } /** * Prepared for sub-class for convenience. Query for list but do not return * total results' number. * * @param select HQL for "select * from ..." and should return object list. * @param values For prepared statements. * @param page Page object for store page information. */ protected List queryForList(final String select, final Object[] values, final Page page) { // select: HibernateCallback selectCallback = new HibernateCallback() { public Object doInHibernate(Session session) { Query query = session.createQuery(select); if(values!=null) { for(int i=0; i<values.length; i++) query.setParameter(i, values[i]); } return query.setFirstResult(page.getFirstResult()) .setMaxResults(page.getPageSize()) .list(); } }; return (List) hibernateTemplate.executeFind(selectCallback); } /** * Prepared for sub-class for convenience. Query for unique result. * * @param select HQL for "select * from ..." and should return unique object. * @param values For prepared statements. */ protected Object queryForObject(final String select, final Object[] values) { HibernateCallback selectCallback = new HibernateCallback() { public Object doInHibernate(Session session) { Query query = session.createQuery(select); if(values!=null) { for(int i=0; i<values.length; i++) query.setParameter(i, values[i]); } return query.uniqueResult(); } }; return hibernateTemplate.execute(selectCallback); } protected Object queryForObject(final DetachedCriteria dc) { HibernateCallback callback = new HibernateCallback() { public Object doInHibernate(Session session) { return dc.getExecutableCriteria(session).uniqueResult(); } }; return hibernateTemplate.execute(callback); } /** * Prepared for sub-class for convenience. */ protected List queryForList(final DetachedCriteria dc, final Page page) { HibernateCallback callback = new HibernateCallback() { public Object doInHibernate(Session session) { Criteria c = dc.getExecutableCriteria(session); if(page==null) return c.list(); return PaginationCriteria.query(c, page); } }; return hibernateTemplate.executeFind(callback); } /** * Prepared for sub-class for convenience. */ protected Object uniqueResult(final DetachedCriteria dc) { HibernateCallback callback = new HibernateCallback() { public Object doInHibernate(Session session) { return dc.getExecutableCriteria(session).uniqueResult(); } }; return hibernateTemplate.execute(callback); } } /** * A PaginationCriteria can execute both "select count(*)" and * "select * from" queries, and set Page object automatically. * This class uses reflect to remove and restore "order by" conditions. * * @author tianheng */ class PaginationCriteria { private static Log log = LogFactory.getLog(PaginationCriteria.class); private static Field orderEntriesField = getField(Criteria.class, "orderEntries"); public static List query(Criteria c, Page page) { // first we must detect if any Order defined: // Hibernate code: private List orderEntries = new ArrayList(); List _old_orderEntries = (List)getFieldValue(orderEntriesField, c); boolean