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 extends HibernateDaoSupport{
??? private ThreadLocal<Session> sessions = new ThreadLocal<Session>();
??? private ThreadLocal<Transaction> transactions = new ThreadLocal<Transaction>();
??? public synchronized 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);
??????? }
??????? return session;
??? }
??? public synchronized void commitMySession(){
??????? Session session = sessions.get();
??????? if(session!=null&&session.isOpen()){
??????????? transactions.get().commit();
??????????? session.close();
??????? }
??????? transactions.remove();
??????? sessions.remove();
??? }
??? public synchronized void rollbackMySession(){
??????? 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);
??? }
??
??? public int execUpdateSQL(String sql, Serializable...values){
??????? Session sess = getMySession();
??????? SQLQuery query = sess.createSQLQuery(sql);
??????? if(values!=null&&values.length>0){
??????????? for(int i=0; i<values.length; i++){
??????????????? query.setParameter(i, values[i]);
??????????? }
??????? }
??????? return query.executeUpdate();
??? }
??? public Long getFirstLong(String sql, final Serializable... values) throws Exception{
??????? 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(obj instanceof Object[]){
??????????? obj = ((Object[])obj)[0];
??????? }
??????? if(obj instanceof 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;
//??? }
??? public List<?> find(String hql){
??????? return getHibernateTemplate().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, final int start, final int limit, final String where, final Serializable... values){
??????? String hql = "from " + clazz.getName() + " as e";
??????? if(where!=null&&where.length()>0){
??????????? hql += " where " + where;
??????? }
??????? final String fHql = hql;
??????? return getHibernateTemplate().executeFind(new HibernateCallback(){
??????????? public Object doInHibernate(Session session)
??????????????????? throws HibernateException, SQLException {
??????????????? Query q = session.createQuery(fHql);
??????????????? if(values!=null&&values.length>0){
??????????????????? for(int i=0; i<values.length; i++){
??????????????????????? q.setParameter(i, values[i]);
??????????????????? }
??????????????? }
??????????????? q.setFirstResult(start).setMaxResults(limit);
??????????????? return q.list();
??????????? }
??????????
??????? });
??? }
??? public <T> List<T> find(Class<T> clazz, final String where, final Serializable... values){
??????? String hql = "from " + clazz.getSimpleName()+" as e";
??????? if(where!=null&&where.length()>0){
??????????? hql += " where " + where;
??????? }
??????? return getHibernateTemplate().find(hql, values);
??? }
??? public long 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);
??????????? return n.longValue();
??????? }
??????? return 0;
??? }
??? public long 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;
??????? }
??????? return getFirstLong(sql, values);
??? }
??
??? public long getTotalCount(String sql, final Serializable... values) throws Exception {
??????? return getFirstLong(sql, values).longValue();
??? }
??? public Object[] findUnique(final String 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(int j=0; j<params.size(); j++){
??????????? query.addScalar(params.get(j), types.get(j));
??????? }
??????? if(values!=null&&values.length>0){
??????????? for(int i=0; i<values.length; i++){
??????????????? query.setParameter(i, values[i]);
??????????? }
??????? }
??????? query.setMaxResults(1);
??????? List<?> list = query.list();
??????? if(list==null||list.size()==0){
??????????? return null;
??????? }
??????? Object obj = list.get(0);
??????? if(obj==null){
??????????? return null;
??????? }
??????? 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(obj instanceof Number){
??????????????? if(obj instanceof Long){
??????????????????? return new Long[]{(Long)(obj)};
??????????????? }
??????????????? if(obj instanceof Integer){
??????????????????? return new Long[]{new Long((Integer)obj)};
??????????????? }
??????????????? return new Number[]{(Number)obj};
??????????? }
??????????? return new Object[]{obj};
??????? }
??????? return (Object[])obj;
??? }
??? public List<Object[]> find(final String 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(int j=0; j<params.size(); j++){
??????????? query.addScalar(params.get(j), types.get(j));
??????? }
??????? if(values!=null&&values.length>0){
??????????? for(int i=0; i<values.length; i++){
??????????????? query.setParameter(i, values[i]);
??????????? }
??????? }
??????? return query.list();
??? }
??? public long 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(obj instanceof Number){
??????????? return ((Number)obj).longValue();
??????? }
??????? return -1L;
??? }
??? public boolean exists(String sql, final Object...values) throws Exception{
??????? Session sess = getMySession();
??????? logger.debug("------exists.getSession()! sess="+sess.hashCode());
??????? SQLQuery query = sess.createSQLQuery(sql);
??????? for(int i=0; i<values.length; i++){
??????????? query.setParameter(i, values[i]);
??????? }
??????? List<?> list = query.list();
??????? if(list==null||list.size()==0){
??????????? return false;
??????? }
??????? return true;
??? }
}
