I've got List<Long> dynamics
. And I want to get max result using Collections
. This is my code:
List<Long> dynamics=spyPathService.getDynamics();
Long max=((Long)Collections.max(dynamics)).longValue();
This is my getDynamics
:
public List<Long> getDynamics() {
Session session = null;
session = this.sessionFactory.getCurrentSession();
Query query = session
.createSQLQuery("SELECT COUNT(*) FROM SpyPath WHERE DATE(time)>=DATE_SUB(CURDATE(),INTERVAL 6 DAY) GROUP BY DATE(time) ORDER BY time;");
List<Long> result = query.list();
return result;
}
Now I'm getting java.math.BigInteger cannot be cast to java.lang.Long
. What's wrong?
This question is related to
java
hibernate
collections
long-integer
biginteger
Are you sure dynamics is a List<Long>
and not List<BigInteger>
?
If dynamics is a List<Long>
you don't need to do a cast to (Long)
Imagine d.getId is a Long, then wrap like this:
BigInteger l = BigInteger.valueOf(d.getId());
Try to convert the BigInteger to a long like this
Long longNumber= bigIntegerNumber.longValue();
You need to add an alias for the count to your query and then use the addScalar()
method as the default for list()
method in Hibernate seams to be BigInteger
for numeric SQL types. Here is an example:
List<Long> sqlResult = session.createSQLQuery("SELECT column AS num FROM table")
.addScalar("num", StandardBasicTypes.LONG).list();
I'm lacking context, but this is working just fine:
List<BigInteger> nums = new ArrayList<BigInteger>();
Long max = Collections.max(nums).longValue(); // from BigInteger to Long...
It's a very old post, but if it benefits anyone, we can do something like this:
Long max=((BigInteger) Collections.max(dynamics)).longValue();
Better option is use SQLQuery#addScalar than casting to Long
or BigDecimal
.
Here is modified query that returns count
column as Long
Query query = session
.createSQLQuery("SELECT COUNT(*) as count
FROM SpyPath
WHERE DATE(time)>=DATE_SUB(CURDATE(),INTERVAL 6 DAY)
GROUP BY DATE(time)
ORDER BY time;")
.addScalar("count", LongType.INSTANCE);
Then
List<Long> result = query.list(); //No ClassCastException here
Related link
Hibernate.LONG
, remember it has been deprecated since Hibernate version 3.6.XLongType.INSTANCE
Source: Stackoverflow.com