Spring 虽然为 Hibernate提供了HibernateDaoSupport 和HibernateTemplate等增强的工具类，在实际的使用中，有时候我们需要将查询出来的信息封装到一个bean中，有时候需要只更新几个列的值，有时候需要做自增，有时候仅仅需要查询一个字段的内容等等；所以很多时候还是需要自己封装一个而已复用的抽象层作为Dao的父类，提供一些通用的方法来实现一些经常用的功能； 这里就分享一个自己觉得很好用的Hibernate Dao抽象实现类，来源是出于对SHOP++项目的源代码学习和改进，加上一些平时对用的频率比较高的方法。

package com.fengyunhe.common.hibernate;import com.fengyunhe.common.bean.Page;
import com.fengyunhe.common.bean.PageList;
import org.apache.commons.lang3.StringUtils;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.query.HQLQueryPlan;
import org.hibernate.engine.query.QueryPlanCache;
import org.springframework.stereotype.Repository;import java.io.Serializable;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;/*** Hibernate dao 基础类，一个Hibernate的dao类继承此抽象类后，需要实现 setSessionFactory 方法，注入数据源** @param <T>  对象类型* @param <PK> 对象主键类型*/
@Repository
public abstract class HibernateBaseDaoImpl<T, PK extends Serializable> implementsHibernateDao<T, PK> {protected SessionFactory sessionFactory;/*** 注入对应的数据源** @param sessionFactory*/protected abstract void setSessionFactory(SessionFactory sessionFactory);private Class<T> entityClass;protected HibernateBaseDaoImpl() {Class c = getClass();Type type = c.getGenericSuperclass();if (type instanceof ParameterizedType) {Type[] parameterizedType = ((ParameterizedType) type).getActualTypeArguments();this.entityClass = (Class<T>) parameterizedType[0];}}@Overridepublic Session getCurrentSession() {return sessionFactory.getCurrentSession();}@Overridepublic Session openSession() {return sessionFactory.openSession();}@Overridepublic void beginTransaction() {getCurrentSession().beginTransaction();}@Overridepublic void commitTransaction() {getCurrentSession().getTransaction().commit();}@Overridepublic void rollbackTransaction() {getCurrentSession().getTransaction().rollback();}@Overridepublic void closeSession(Session session) {session.close();}@Overridepublic T getById(PK id) {return (T) getCurrentSession().get(entityClass, id);}@Overridepublic T loadById(PK id) {return (T) getCurrentSession().load(entityClass, id);}@Overridepublic <T1> T1 getPropertyById(PK id, String propertyName, Class<T1> clazz) {return getUniqueResult(clazz, "select " + propertyName + " from " + entityClass.getName() + " where " + sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName() + "=?", id);}@Overridepublic void save(T model) {getCurrentSession().save(model);}@Overridepublic void saveOrUpdate(T model) {getCurrentSession().saveOrUpdate(model);}@Overridepublic List<T> findListByProperty(String propertyName, Object value) {Query query = getCurrentSession().createQuery("from " + entityClass.getName() + " where " + propertyName + "=?");query.setParameter(0, value);return query.list();}@Overridepublic void delete(T model) {getCurrentSession().delete(model);}@Overridepublic void deleteById(PK... id) {for (int i = 0; i < id.length; i++) {execute("delete from " + entityClass.getName() + " where " + sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName() + "=?", id[i]);}}@Overridepublic void update(T model) {getCurrentSession().update(model);}@Overridepublic List<T> findAll() {return getCurrentSession().createCriteria(entityClass.getName()).list();}@Overridepublic void deleteResultsByProperty(String propertyName, Object value) {Query query = getCurrentSession().createQuery("delete from " + entityClass.getName() + " where " + propertyName + "=?");query.setParameter(0, value);query.executeUpdate();}@Overridepublic PageList<T> findByPage(Page page, String hql, List<Object> params) {Query q = getCurrentSession().createQuery(hql);if (page instanceof Page.Offset) {q.setFirstResult(((Page.Offset) page).getStart()).setMaxResults(((Page.Offset) page).getLimit());} else {q.setFirstResult((page.getPage() - 1) * page.getPageSize()).setMaxResults(page.getPageSize());}if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}page.setTotal(this.getTotalCount(hql, params));return new PageList<T>(page, q.list());}@Overridepublic PageList<T> findByPage(Page page) {return this.findByPage(page, "from " + this.entityClass.getName(),Collections.EMPTY_LIST);}@Overridepublic PageList<T> findByPage(Page page, String hql, Object... params) {return this.findByPage(page, hql, Arrays.asList(params));}@Overridepublic void clear() {getCurrentSession().clear();}@Overridepublic void flush() {getCurrentSession().flush();}@Overridepublic void evict(Object o) {getCurrentSession().evict(o);}@Overridepublic boolean isExist(String propertyName, Object value) {String hql = "select count(*) from " + entityClass.getName()+ " where " + propertyName + "=?";return (Long) getCurrentSession().createQuery(hql).setParameter(0, value).uniqueResult() > 0;}@Overridepublic long getTotalCount() {String hql = "select count(*) from " + entityClass.getName();return Long.valueOf(getCurrentSession().createQuery(hql).uniqueResult().toString());}@Overridepublic long getTotalCount(String hql, List<Object> params) {Query q = getCurrentSession().createQuery(prepareCountHql(hql));if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}Object singleResult = q.uniqueResult();if (singleResult instanceof Object[]) {return Long.valueOf(((Object[]) singleResult)[0].toString()).longValue();}return Long.valueOf(singleResult.toString()).longValue();}@Overridepublic long getTotalCount(String hql, Object... params) {return this.getTotalCount(hql,params == null ? null : Arrays.asList(params));}protected String prepareCountHql(String hql) {String fromHql = hql;fromHql = " from " + StringUtils.substringAfter(fromHql, "from ");fromHql = StringUtils.substringBefore(fromHql, "order by");
//取出查询的字段String selectWhat = StringUtils.substringBetween(hql, "select", "from");
//        如果是new ClassName (x.x.x)格式的处理if (selectWhat != null && selectWhat.contains("new ") && selectWhat.contains("(") && selectWhat.contains(")")) {selectWhat = StringUtils.substringBetween(selectWhat, "(", ")");}
//        第一列查询总行数String countHql = "select count(*)" + (selectWhat == null ? "" : ", " + selectWhat + " ") + fromHql;return countHql;}protected String getCountSql(String originalHql,SessionFactory sessionFactory) {SessionFactoryImplementor sessionFactoryImplementor = (SessionFactoryImplementor) sessionFactory;HQLQueryPlan hqlQueryPlan = sessionFactoryImplementor.getQueryPlanCache().getHQLQueryPlan(originalHql, false,Collections.emptyMap());String[] sqls = hqlQueryPlan.getSqlStrings();String countSql = "select count(*) from (" + sqls[0] + ") count";return countSql;}public SessionFactoryImplementor getSessionFactoryImplementor() {return (SessionFactoryImplementor) sessionFactory;}public QueryPlanCache getQueryPlanCache() {return getSessionFactoryImplementor().getQueryPlanCache();}public HQLQueryPlan getHqlQueryPlan(String hql) {return getQueryPlanCache().getHQLQueryPlan(hql, false,Collections.emptyMap());}protected String prepareCountSql(String sql) {return getCountSql(sql, sessionFactory);}@Overridepublic <T> List<T> findList(Class<T> clazz, String hql, List<Object> params) {Query q = getCurrentSession().createQuery(hql);if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}return q.list();}@Overridepublic <T> List<T> findListLimit(Class<T> clazz, String hql, int limit,List<Object> params) {Query q = getCurrentSession().createQuery(hql);if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}q.setFirstResult(0);q.setMaxResults(limit);return q.list();}@Overridepublic T getUniqueResult(String hql, Object... params) {return getUniqueResult(this.entityClass, hql, params);}@Overridepublic <T> T getUniqueResult(Class<T> clazz, String hql, List<Object> params) {Query q = getCurrentSession().createQuery(hql);if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}q.setFirstResult(0);q.setMaxResults(1);List list = q.list();if (list == null || list.isEmpty() || list.get(0) == null) {return null;}return (T) list.get(0);}@Overridepublic <T> List<T> findList(Class<T> clazz, String hql, Object... params) {return this.findList(clazz, hql,params == null ? null : Arrays.asList(params));}@Override/*** 用给定的HQL和参数查询前几条给定类型的数据列表* @param clazz* @param hql* @param limit* @param params* @return*/public <T> List<T> findListLimit(Class<T> clazz, String hql, int limit,Object... params) {return this.findListLimit(clazz, hql, limit, params == null ? null: Arrays.asList(params));}@Overridepublic <T> PageList<T> findPageList(Page page, Class<T> clazz, String hql,Object... params) {return findPageList(page, clazz, hql, Arrays.asList(params));}@Overridepublic <T> PageList<T> findPageList(Page page, Class<T> clazz, String hql,List<Object> params) {Query q = getCurrentSession().createQuery(hql);if (page instanceof Page.Offset) {q.setFirstResult(((Page.Offset) page).getStart()).setMaxResults(((Page.Offset) page).getLimit());} else {q.setFirstResult((page.getPage() - 1) * page.getPageSize()).setMaxResults(page.getPageSize());}if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}page.setTotal(this.getTotalCount(hql, params));return new PageList(page, q.list());}@Overridepublic T getUniqueResultByProperty(String propertyName, Object value) {return this.getUniqueResult("from " + this.entityClass.getName()+ " where " + propertyName + "=?", value);}@Overridepublic <T> T getUniqueResult(Class<T> clazz, String hql, Object... params) {return this.getUniqueResult(clazz, hql,params == null ? null : Arrays.asList(params));}@Overridepublic void execute(String hql, List<Object> params) {Query q = this.getCurrentSession().createQuery(hql);if (params != null) {for (int i = 0; i < params.size(); i++) {q.setParameter(i, params.get(i));}}q.executeUpdate();}@Overridepublic void execute(String hql, Object... params) {this.execute(hql, params == null ? null : Arrays.asList(params));}@Overridepublic void updateProperty(PK id, String propertyName, Object status) {String hql = "update " + this.entityClass.getName() + " set " + propertyName + " = ? where " + sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName() + "= ?";this.execute(hql, status, id);}@Overridepublic void incr(PK id, String propertyName) {String hql = "update " + this.entityClass.getName() + " set " + propertyName + " = " + propertyName + "+1 where " + sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName() + "= ?";this.execute(hql, id);}@Overridepublic void incr(PK id, String propertyName, Integer n) {String hql = "update " + this.entityClass.getName() + " set " + propertyName + " = " + propertyName + "+1 where " + sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName() + "= ?";this.execute(hql, id, n);}@Overridepublic void updateProperties(PK id, String[] propertyNames, Object[] values) {String hql = "update " + entityClass.getName() + " set ";for (int i = 0; i < propertyNames.length; i++) {hql += propertyNames[i] + "= :v" + i;if (i + 1 < propertyNames.length) {hql += ",";}}hql += " where " + getIdPropertyName() + " =:id";Query query = getCurrentSession().createQuery(hql);for (int i = 0; i < values.length; i++) {query.setParameter("v" + i, values[i]);}query.setParameter("id", id).executeUpdate();}public String getIdPropertyName() {return sessionFactory.getClassMetadata(this.entityClass).getIdentifierPropertyName();}@Overridepublic boolean deleteAll() {String hql = "delete " + this.entityClass.getName();this.execute(hql);return true;}
}

tips：

本文由wp2Blog导入，原文链接：http://devonios.com/hibernate-%e5%b0%81%e8%a3%85%e7%9a%84%e9%80%9a%e7%94%a8dao%e5%9f%ba%e7%a1%80%e7%b1%bb.html