/** 在HQL的后面添加分页参数定义的orderBy, 辅助函数. */
protected String setPageRequestToHql(String hql, PageRequest pageRequest) {
if (CollectionUtils.isEmpty(pageRequest.getSort())) {
return hql;
}
StringBuilder builder = new StringBuilder(hql);
builder.append(" order by");
for (PageRequest.Sort orderBy : pageRequest.getSort()) {
builder.append(String.format(" %s %s,", orderBy.getProperty(), orderBy.getDir()));
}
builder.deleteCharAt(builder.length() - 1);
return builder.toString();
}
/**
* 设置分页参数到Criteria对象,辅助函数.
*
* @param c Hibernate Criteria
* @param pageRequest 分页请求参数
* @return {@link org.hibernate.Criteria}
*/
protected Criteria setPageRequestToCriteria(Criteria c, PageRequest pageRequest) {
Assert.isTrue(pageRequest.getPageSize() > 0, "分页大小必须大于0");
c.setFirstResult(pageRequest.getOffset());
c.setMaxResults(pageRequest.getPageSize());
if (pageRequest.isOrderBySetted()) {
for (PageRequest.Sort sort : pageRequest.getSort()) {
Order order = null;
if (sort.getDir().equals(PageRequest.Sort.ASC)) {
order = Order.asc(sort.getProperty());
} else {
order = Order.desc(sort.getProperty());
}
c.addOrder(order);
}
}
return c;
}
/**
* 根据分页请求参数与Query获取分页请求对象
*
* @param request 分页请求参数对象
* @param query Hibernate Query
* @return {@link Page}
*/
public <X> Page<X> findPage(PageRequest request, Query query) {
Page<X> page = new Page<X>(request);
if (request == null) {
return page;
}
AbstractQueryImpl impl = (AbstractQueryImpl) query;
String queryString = setPageRequestToHql(impl.getQueryString(), request);
ReflectionUtils.setFieldValue(impl, "queryString", queryString);
if (request.isCountTotal()) {
long totalCount = 0;
if (impl.hasNamedParameters()) {
Map<String, TypedValue> map = ReflectionUtils.getFieldValue(impl, "namedParameters");
Map<String, Object> values = new HashMap<String, Object>();
for (Map.Entry<String, TypedValue> entry : map.entrySet()) {
values.put(entry.getKey(), entry.getValue().getValue());
}
totalCount = countHqlResult(impl.getQueryString(), values);
} else {
List<Object> values = ReflectionUtils.invokeGetter(impl, "values");
totalCount = countHqlResult(impl.getQueryString(), values.toArray());
}
page.setTotalItems(totalCount);
}
impl.setFirstResult(request.getOffset());
impl.setMaxResults(request.getPageSize());
List result = impl.list();
page.setResult(result);
return page;
}
/**
* 根据分页参数与Criteria获取分页对象
*
* @param request 分页请求参数
* @param c Criteria对象
* @return {@link Page}
*/
public Page<T> findPage(PageRequest request, Criteria c) {
Page<T> page = new Page<T>(request);
if (request == null) {
return page;
}
if (request.isCountTotal()) {
long totalCount = countCriteriaResult(c);
page.setTotalItems(totalCount);
}
setPageRequestToCriteria(c, request);
List result = c.list();
page.setResult(result);
return page;
}
