Eclipselink中的标准查询缓存缓存？

Question

Iam使用EclipseLink作为JPA的标准查询。我需要根据查询结果的参数来缓存它们。当我使用query.setHint("eclipselink.QUERY_RESULTS_CACHE", "TRUE")时，它仍然会向数据库发出查询。如何在标准查询的上下文中使用它？

在这里，我设置了我的查询及其提示和addNamedQuery

Query query = psEntityManager.getEntityManager().createQuery(criteriaQuery);// Creating Query to supply Values
        query.setHint("eclipselink.QUERY_RESULTS_CACHE", "TRUE");
        query.setHint(QueryHints.QUERY_TYPE,QueryType.ReadObject);
        psEntityManager.getEntityManager().getEntityManagerFactory().addNamedQuery("query1", query);

这是我的输出：

Query1-----------
[EL Fine]: sql: 2013-10-10 21:33:35.495--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, ADDRESSLINE1, ADDRESSLINE2, PHONENUMBER, fkCityId, fkPersonId FROM ADDRESS WHERE (fkPersonId = ?)
    bind => [2]
[EL Fine]: sql: 2013-10-10 21:33:35.527--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, CITYNAME, PINCODE, fkStateId FROM CITY WHERE (PRIMARYKEY = ?)
    bind => [2]
[EL Fine]: sql: 2013-10-10 21:33:35.528--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, STATENAME FROM STATE WHERE (PRIMARYKEY = ?)
    bind => [1]
[EL Fine]: sql: 2013-10-10 21:33:35.531--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, AGE, DOB, FIRSTNAME, LASTNAME, SEX, TIMESTAMP, fkDepartmentId FROM PERSON WHERE (PRIMARYKEY = ?)
    bind => [2]
[EL Fine]: sql: 2013-10-10 21:33:35.541--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, DEPTNAME FROM DEPARTMENT WHERE (PRIMARYKEY = ?)
    bind => [2]
[EL Fine]: sql: 2013-10-10 21:33:35.547--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, CITYNAME, PINCODE, fkStateId FROM CITY WHERE (PRIMARYKEY = ?)
    bind => [5]
[EL Fine]: sql: 2013-10-10 21:33:35.548--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, STATENAME FROM STATE WHERE (PRIMARYKEY = ?)
    bind => [3]
[EL Fine]: sql: 2013-10-10 21:33:35.551--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, CITYNAME, PINCODE, fkStateId FROM CITY WHERE (PRIMARYKEY = ?)
    bind => [8]
[EL Fine]: sql: 2013-10-10 21:33:35.553--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, STATENAME FROM STATE WHERE (PRIMARYKEY = ?)
    bind => [4]
Query2-----------
[EL Fine]: sql: 2013-10-10 21:33:35.557--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, ADDRESSLINE1, ADDRESSLINE2, PHONENUMBER, fkCityId, fkPersonId FROM ADDRESS WHERE (fkPersonId = ?)
    bind => [2]
Query3-----------
[EL Fine]: sql: 2013-10-10 21:33:35.56--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, ADDRESSLINE1, ADDRESSLINE2, PHONENUMBER, fkCityId, fkPersonId FROM ADDRESS WHERE (fkPersonId = ?)
    bind => [2]
Query4-----------
[EL Fine]: sql: 2013-10-10 21:33:35.563--ServerSession(14144548)--Connection(7200601)--SELECT PRIMARYKEY, ADDRESSLINE1, ADDRESSLINE2, PHONENUMBER, fkCityId, fkPersonId FROM ADDRESS WHERE (fkPersonId = ?)
    bind => [2]

Answer 1

删除query.setHint(QueryHints.QUERY_TYPE，QueryType.ReadObject)，或者先调用它。query_type更改底层查询对象，并不是所有提示都可能被复制到新对象中。反正也没什么必要的。