springside 增强dao

/**
* 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 org.springside.modules.orm.hibernate;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.lang.StringUtils;
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.DetachedCriteria;
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.internal.CriteriaImpl;
import org.hibernate.transform.ResultTransformer;
import org.springframework.util.Assert;
import org.springside.modules.orm.Page;
import org.springside.modules.orm.PropertyFilter;
import org.springside.modules.orm.PropertyFilter.MatchType;
import org.springside.modules.utils.reflection.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> {
/**
* 保存对象别名，以免重复添加导致Hibernate报异常.
*/
Set<String> aliases = new HashSet<String>();

/**
* 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.
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
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", "rawtypes" })
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", "rawtypes" })
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);
}

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 (orderByArray[i].contains(".")) {
String alias = StringUtils.substringBefore(orderByArray[i], ".");
if (!aliases.contains(alias)) {
c.createAlias(alias, alias);
aliases.add(alias);
}
}
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", "rawtypes" })
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) c.setProjection(Projections.rowCount()).uniqueResult();
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);
}*/

/**
* 按属性过滤条件列表分页查找对象.
* 添加了关联查询和关联排序功能 add by henryyan.
*/
@SuppressWarnings( { "unchecked", "rawtypes" })
public Page<T> findPage(final Page<T> page, final List<PropertyFilter> filters) {
Assert.notNull(page, "page不能为空");
DetachedCriteria dc = buildPropertyFilterDetachedCriteria(filters);
Criteria c = dc.getExecutableCriteria(getSession());
if (page.isAutoCount()) {
long totalCount = countCriteriaResult(c);
page.setTotalCount(totalCount);
}
setPageParameterToCriteria(c, page);
aliases = new HashSet<String>();
List result = c.list();
page.setResult(result);
return page;
}

protected DetachedCriteria buildPropertyFilterDetachedCriteria(final List<PropertyFilter> filters) {
DetachedCriteria dc = DetachedCriteria.forClass(entityClass);
for (PropertyFilter filter : filters) {
if (!filter.hasMultiProperties()) {
if (filter.getPropertyName().contains(".")) {
String alias = StringUtils.substringBefore(filter.getPropertyName(), ".");
if (!aliases.contains(alias)) {
dc.createAlias(alias, alias, CriteriaSpecification.LEFT_JOIN); //默认用left join
aliases.add(alias);
}
}
} else { //含有or的情况
for (String propertyName : filter.getPropertyNames()) {
if (propertyName.contains(".")) {
String alias = StringUtils.substringBefore(filter.getPropertyName(), ".");
if (!aliases.contains(alias)) {
dc.createAlias(alias, alias, CriteriaSpecification.LEFT_JOIN);
aliases.add(alias);
}
}
}
}
}
Criterion[] criterions = buildCriterionByPropertyFilter(filters);
for (Criterion criterion : criterions) {
dc.add(criterion);
}
return dc;
}

/**
* 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()]);
}
}