CODEWITHSUNDEEP
javahibernatehql
Suhail Gupta
Suhail Gupta

Reputation: 23226

Why am I getting a ClassCastException as I try to get a property of type Long?

On running the following snippet :

String hqlSelect = "select bookID from Issued where regID = " + regID;
    List list = sess.createQuery(hqlSelect).list();
    Iterator i = list.iterator();
    while(i.hasNext()) {
        Issued issued = (Issued) i.next(); // LINE : 46
        bookIdList.add(issued.getBookID());
    }

line number 46 generates an exception.

java.lang.ClassCastException: java.lang.Long cannot be cast to pojo.Issued

In the query bookID and regID are of type Long and issued is a class that contains bookID and regID.

Why am I getting this exception ?

Upvotes: 1

Views: 195

Answers (4)

Kartik73
Kartik73

Reputation: 513

try using below code.

String hqlSelect = "select new java.lang.Long(bookID) from Issued where regID = " + regID;
List<Long> list = (List<Long>)sess.createQuery(hqlSelect).list();
Iterator<Long> i = list.iterator();
while(i.hasNext()) {
    bookIdList.add(i);
}

You can also use for each loop

for (Long i : list) {
bookIdList.add(i);
}

Upvotes: 1

fachammer
fachammer

Reputation: 181

You do not need the select clause for selecting objects in HQL (see HQL Reference). So you can just use the following HQL query:

String hqlSelect = "from Issued where regID = " + regID;

and the query it will return a list of objects which can be cast to Issued.

Upvotes: 0

Masudul
Masudul

Reputation: 21961

Use following code to get bookID

String hqlSelect = "select bookID from Issued where regID = " + regID;
    List<Object[]> list = sess.createQuery(hqlSelect).list();

for (Object[] result : list) {        
    long bookId = ((Number) result[0]).longValue();
}

Upvotes: 0

Manoj
Manoj

Reputation: 329

String hqlSelect = "select bookID from Issued where regID = " + regID;

This query seems like a normal native query. It will give Object[] List.

List<Object> list = sess.createNativeQuery(hqlSelect).list();

if u are using JPA query you can get Issued objects (if you have POJO Object for Issued)

Upvotes: 0

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