/**
* Copyright (c) 2005-2010 springside.org.cn
*
* Licensed under the Apache License, Version 2.0 (the "License");
*
* $Id: HibernateDao.java 1205 2010-09-09 15:12:17Z calvinxiu $
*/
package com.dao.hibernate;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.math.NumberUtils;
import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.CriteriaSpecification;
import org.hibernate.criterion.Criterion;
import org.hibernate.criterion.Disjunction;
import org.hibernate.criterion.MatchMode;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projection;
import org.hibernate.criterion.Projections;
import org.hibernate.criterion.Restrictions;
import org.hibernate.impl.CriteriaImpl;
import org.hibernate.transform.ResultTransformer;
import org.springframework.util.Assert;
import com.dao.hibernate.PropertyFilter.MatchType;
import com.utils.ReflectionUtils;
/**
* 封装SpringSide扩展功能的Hibernat DAO泛型基类.
*
* 扩展功能包括分页查询,按属性过滤条件列表查询. 可在Service层直接使用,也可以扩展泛型DAO子类使用,见两个构造函数的注释.
*
* @param <T>
* DAO操作的对象类型
* @param <PK>
* 主键类型
*
* @author calvin
*/
public class HibernateDao<T, PK extends Serializable> extends
SimpleHibernateDao<T, PK> {
/**
* 用于Dao层子类的构造函数. 通过子类的泛型定义取得对象类型Class. eg. public class UserDao extends
* HibernateDao<User, Long>{ }
*/
public HibernateDao() {
super();
}
/**
* 用于省略Dao层, Service层直接使用通用HibernateDao的构造函数. 在构造函数中定义对象类型Class. eg.
* HibernateDao<User, Long> userDao = new HibernateDao<User,
* Long>(sessionFactory, User.class);
*/
public HibernateDao(final SessionFactory sessionFactory,
final Class<T> entityClass) {
super(sessionFactory, entityClass);
}
// -- 分页查询函数 --//
/**
* 分页获取全部对象.
*/
public Page<T> getAll(final Page<T> page) {
return findPage(page);
}
/**
* 按HQL分页查询.
*
* @param page
* 分页参数. 注意不支持其中的orderBy参数.
* @param hql
* hql语句.
* @param values
* 数量可变的查询参数,按顺序绑定.
*
* @return 分页查询结果, 附带结果列表及所有查询输入参数.
*/
public Page<T> findPage(final Page<T> page, final String hql,
final Object... values) {
Assert.notNull(page, "page不能为空");
Query q = createQuery(hql, values);
if (page.isAutoCount()) {
long totalCount = countHqlResult(hql, values);
page.setTotalCount(totalCount);
}
setPageParameterToQuery(q, page);
List result = q.list();
page.setResult(result);
return page;
}
/**
* 按HQL分页查询.
*
* @param page
* 分页参数. 注意不支持其中的orderBy参数.
* @param hql
* hql语句.
* @param values
* 命名参数,按名称绑定.
*
* @return 分页查询结果, 附带结果列表及所有查询输入参数.
*/
@SuppressWarnings("unchecked")
public Page<T> findPage(final Page<T> page, final String hql,
final Map<String, ?> values) {
Assert.notNull(page, "page不能为空");
Query q = createQuery(hql, values);
if (page.isAutoCount()) {
long totalCount = countHqlResult(hql, values);
page.setTotalCount(totalCount);
}
setPageParameterToQuery(q, page);
List result = q.list();
page.setResult(result);
return page;
}
/**
* 按Criteria分页查询.
*
* @param page
* 分页参数.
* @param criterions
* 数量可变的Criterion.
*
* @return 分页查询结果.附带结果列表及所有查询输入参数.
*/
@SuppressWarnings("unchecked")
public Page<T> findPage(final Page<T> page, final Criterion... criterions) {
Assert.notNull(page, "page不能为空");
Criteria c = createCriteria(criterions);
if (page.isAutoCount()) {
long totalCount = countCriteriaResult(c);
page.setTotalCount(totalCount);
}
if(page.getPageNo() > page.getTotalPages()) {
page.setPageNo(NumberUtils.toInt(Long.toString(page.getTotalPages())));
}
setPageParameterToCriteria(c, page);
List result = c.list();
page.setResult(result);
return page;
}
/**
* 设置分页参数到Query对象,辅助函数.
*/
protected Query setPageParameterToQuery(final Query q, final Page<T> page) {
Assert.isTrue(page.getPageSize() > 0, "Page Size must larger than zero");
// hibernate的firstResult的序号从0开始
q.setFirstResult(page.getFirst() - 1);
q.setMaxResults(page.getPageSize());
return q;
}
/**
* 设置分页参数到Criteria对象,辅助函数.
*/
protected Criteria setPageParameterToCriteria(final Criteria c,
final Page<T> page) {
Assert.isTrue(page.getPageSize() > 0, "Page Size must larger than zero");
// hibernate的firstResult的序号从0开始
c.setFirstResult(page.getFirst() - 1);
c.setMaxResults(page.getPageSize());
if (page.isOrderBySetted()) {
String[] orderByArray = StringUtils.split(page.getOrderBy(), ',');
String[] orderArray = StringUtils.split(page.getOrder(), ',');
Assert.isTrue(orderByArray.length == orderArray.length,
"分页多重排序参数中,排序字段与排序方向的个数不相等");
for (int i = 0; i < orderByArray.length; i++) {
if (Page.ASC.equals(orderArray[i])) {
c.addOrder(Order.asc(orderByArray[i]));
} else {
c.addOrder(Order.desc(orderByArray[i]));
}
}
}
return c;
}
/**
* 执行count查询获得本次Hql查询所能获得的对象总数.
*
* 本函数只能自动处理简单的hql语句,复杂的hql查询请另行编写count语句查询.
*/
protected long countHqlResult(final String hql, final Object... values) {
String countHql = prepareCountHql(hql);
try {
Long count = findUnique(countHql, values);
return count;
} catch (Exception e) {
throw new RuntimeException("hql can't be auto count, hql is:"
+ countHql, e);
}
}
/**
* 执行count查询获得本次Hql查询所能获得的对象总数.
*
* 本函数只能自动处理简单的hql语句,复杂的hql查询请另行编写count语句查询.
*/
protected long countHqlResult(final String hql, final Map<String, ?> values) {
String countHql = prepareCountHql(hql);
try {
Long count = findUnique(countHql, values);
return count;
} catch (Exception e) {
throw new RuntimeException("hql can't be auto count, hql is:"
+ countHql, e);
}
}
private String prepareCountHql(String orgHql) {
String fromHql = orgHql;
// select子句与order by子句会影响count查询,进行简单的排除.
fromHql = "from " + StringUtils.substringAfter(fromHql, "from");
fromHql = StringUtils.substringBefore(fromHql, "order by");
String countHql = "select count(*) " + fromHql;
return countHql;
}
/**
* 执行count查询获得本次Criteria查询所能获得的对象总数.
*/
@SuppressWarnings("unchecked")
protected long countCriteriaResult(final Criteria c) {
CriteriaImpl impl = (CriteriaImpl) c;
// 先把Projection、ResultTransformer、OrderBy取出来,清空三者后再执行Count操作
Projection projection = impl.getProjection();
ResultTransformer transformer = impl.getResultTransformer();
List<CriteriaImpl.OrderEntry> orderEntries = null;
try {
orderEntries = (List) ReflectionUtils.getFieldValue(impl,
"orderEntries");
ReflectionUtils
.setFieldValue(impl, "orderEntries", new ArrayList());
} catch (Exception e) {
logger.error("不可能抛出的异常:{}", e.getMessage());
}
// 执行Count查询
Long totalCountObject = Long.parseLong(c
.setProjection(Projections.rowCount()).uniqueResult()
.toString());
long totalCount = (totalCountObject != null) ? totalCountObject : 0;
// 将之前的Projection,ResultTransformer和OrderBy条件重新设回去
c.setProjection(projection);
if (projection == null) {
c.setResultTransformer(CriteriaSpecification.ROOT_ENTITY);
}
if (transformer != null) {
c.setResultTransformer(transformer);
}
try {
ReflectionUtils.setFieldValue(impl, "orderEntries", orderEntries);
} catch (Exception e) {
logger.error("不可能抛出的异常:{}", e.getMessage());
}
return totalCount;
}
// -- 属性过滤条件(PropertyFilter)查询函数 --//
/**
* 按属性查找对象列表,支持多种匹配方式.
*
* @param matchType
* 匹配方式,目前支持的取值见PropertyFilter的MatcheType enum.
*/
public List<T> findBy(final String propertyName, final Object value,
final MatchType matchType) {
Criterion criterion = buildCriterion(propertyName, value, matchType);
return find(criterion);
}
/**
* 按属性过滤条件列表查找对象列表.
*/
public List<T> find(List<PropertyFilter> filters) {
Criterion[] criterions = buildCriterionByPropertyFilter(filters);
return find(criterions);
}
/**
* 按属性过滤条件列表分页查找对象.
*/
public Page<T> findPage(final Page<T> page,
final List<PropertyFilter> filters) {
Criterion[] criterions = buildCriterionByPropertyFilter(filters);
return findPage(page, criterions);
}
/**
* 按属性条件参数创建Criterion,辅助函数.
*/
protected Criterion buildCriterion(final String propertyName,
final Object propertyValue, final MatchType matchType) {
Assert.hasText(propertyName, "propertyName不能为空");
Criterion criterion = null;
// 根据MatchType构造criterion
switch (matchType) {
case EQ:
criterion = Restrictions.eq(propertyName, propertyValue);
break;
case LIKE:
criterion = Restrictions.like(propertyName, (String) propertyValue,
MatchMode.ANYWHERE);
break;
case LE:
criterion = Restrictions.le(propertyName, propertyValue);
break;
case LT:
criterion = Restrictions.lt(propertyName, propertyValue);
break;
case GE:
criterion = Restrictions.ge(propertyName, propertyValue);
break;
case GT:
criterion = Restrictions.gt(propertyName, propertyValue);
}
return criterion;
}
/**
* 按属性条件列表创建Criterion数组,辅助函数.
*/
protected Criterion[] buildCriterionByPropertyFilter(
final List<PropertyFilter> filters) {
List<Criterion> criterionList = new ArrayList<Criterion>();
for (PropertyFilter filter : filters) {
if (!filter.hasMultiProperties()) { // 只有一个属性需要比较的情况.
Criterion criterion = buildCriterion(filter.getPropertyName(),
filter.getMatchValue(), filter.getMatchType());
criterionList.add(criterion);
} else {// 包含多个属性需要比较的情况,进行or处理.
Disjunction disjunction = Restrictions.disjunction();
for (String param : filter.getPropertyNames()) {
Criterion criterion = buildCriterion(param,
filter.getMatchValue(), filter.getMatchType());
disjunction.add(criterion);
}
criterionList.add(disjunction);
}
}
return criterionList.toArray(new Criterion[criterionList.size()]);
}
}
原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/tech/pnotes/10098.html