java.math.BigInteger cannot be cast to java.lang.Long

Question

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?

Because a java.math.BigInteger class instance is not an instance of java.lang.Long class. — Luiggi Mendoza
– Luiggi Mendoza, Commented Aug 21, 2013 at 15:30
You're going to need to provide more code if you want more help. Maybe the line the error is pointing to? And what type does getDynamics() return? — Eric Stein
– Eric Stein, Commented Aug 21, 2013 at 15:30
you have your answer in your question, i assume this Collections.max(dynamics)) is BigInteger, and you are trying cast it to long, try to cast it to BigInteger, and then use longValue()method — user902383
– user902383, Commented Aug 21, 2013 at 15:32
Ok people, he's clearly labeled his dynamics list as a List<Long>. @Tony Check the return type of spyPathService.getDynamics(). Assuming your error is actually coming from these lines of code, I would guess from this code that spyPathService.getDynamics() is actually returning a List that at the very least includes some BigIntegers — StormeHawke
– StormeHawke, Commented Aug 21, 2013 at 15:34

Community · Accepted Answer · 2017-05-23 12:02:53Z

35

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 javadocs
Scalar queries
Hibernate.LONG, remember it has been deprecated since Hibernate version 3.6.X
here is the deprecated document, so you have to use LongType.INSTANCE
My previous answer

edited May 23, 2017 at 12:02

CommunityBot

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answered Nov 28, 2013 at 10:48

Aniket Kulkarni

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1 Comment

gavenkoa Over a year ago

You are hero! +1, but really +100!

Amin Abu-Taleb · Accepted Answer · 2013-08-21 15:34:19Z

26

Your error might be in this line:

List<Long> result = query.list();

where query.list() is returning a BigInteger List instead of Long list. Try to change it to.

List<BigInteger> result = query.list();

answered Aug 21, 2013 at 15:34

Amin Abu-Taleb

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3 Comments

mike Over a year ago

As @StormeHawke said '...is actually returning a List that at the very least includes some BigIntegers'. So you better find out exactly, before you run into the next problem of this kind.

gavenkoa Over a year ago

This answer lies on wrong assumption about internal Hibernate wrapper types! The only Aniket Kulkarni answer SQLQuery#addScalar is right!

Bills Over a year ago

I also type cast the list

Abstract · Accepted Answer · 2013-08-21 15:34:44Z

17

Try to convert the BigInteger to a long like this

Long longNumber= bigIntegerNumber.longValue();

answered Aug 21, 2013 at 15:34

Abstract

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Comments

mike · Accepted Answer · 2013-08-21 15:32:07Z

3

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...

answered Aug 21, 2013 at 15:32

mike

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1 Comment

Tony Over a year ago

I heard that COUNT(*) statement returns Long. Doesn't it?

Jai Aggarwal · Accepted Answer · 2019-11-29 08:47:17Z

3

It's a very old post, but if it benefits anyone, we can do something like this:

Long max=((BigInteger) Collections.max(dynamics)).longValue();

answered Nov 29, 2019 at 8:47

Jai Aggarwal

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Comments

Ash Burlaczenko · Accepted Answer · 2013-08-21 15:32:43Z

1

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)

edited Aug 21, 2013 at 15:32

Ash Burlaczenko

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answered Aug 21, 2013 at 15:31

dkatzel

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Comments

Bert Verhees · Accepted Answer · 2016-10-18 18:00:35Z

1

Imagine d.getId is a Long, then wrap like this:

BigInteger l  = BigInteger.valueOf(d.getId());

answered Oct 18, 2016 at 18:00

Bert Verhees

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Comments

DevNG · Accepted Answer · 2017-08-22 15:09:40Z

1

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();

answered Aug 22, 2017 at 15:09

DevNG

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jsmin · Accepted Answer · 2022-03-06 15:37:13Z

0

You need to retrieve the result as List of BigInteger then convert it to a Long collection.

List<BigInteger> ids = query.getResultList();
Set<Long> collect = ids.stream().map(id -> id.longValue()).collect(Collectors.toSet());

answered Mar 6, 2022 at 15:37

jsmin

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