Out of Memory Error in hibernate when querying a table with large data

Question

I am Querying a table using Hibernate by i get the error

"Exception in thread 
"Thread-4" java.lang.OutOfMemoryError: Java heap space at  
    java.util.Arrays.copyOf(Arrays.java:3222) at
     java.util.Arrays.copyOf(Arrays.java:3222)".

Here is My sample code.

 public   List<MyBean> loadData() {
    Session s=CFactory.getSession();
    s.beginTransaction();
     List<MyBean> mybean=null;
    try {
      Query sry=s.createQuery("from MyBean where flag='NP'");
       mybean=sry.list();
     s.getTransaction().commit();

    } catch (Exception e) {
        e.printStackTrace();
    }
    return mybean;
}

My question is how can i query in a table that has a huge data and convert it to a list without getting out of memory error in hibernate?

Exception in thread "Thread-4" java.lang.OutOfMemoryError: Java heap space
    at java.util.Arrays.copyOf(Arrays.java:3222)
    at java.util.Arrays.copyOf(Arrays.java:3222)
    at java.io.ByteArrayOutputStream.grow(ByteArrayOutputStream.java:113)
    at java.io.ByteArrayOutputStream.ensureCapacity(ByteArrayOutputStream.java:93)
    at java.io.ByteArrayOutputStream.write(ByteArrayOutputStream.java:140)
    at org.hibernate.type.descriptor.java.DataHelper.extractBytes(DataHelper.java:170)
    at org.hibernate.type.descriptor.java.DataHelper.extractBytes(DataHelper.java:170)
    at org.hibernate.type.descriptor.java.PrimitiveByteArrayTypeDescriptor.wrap(PrimitiveByteArrayTypeDescriptor.java:124)
    at org.hibernate.type.descriptor.java.PrimitiveByteArrayTypeDescriptor.wrap(PrimitiveByteArrayTypeDesciptor.java:41)
    at org.hibernate.type.descriptor.sql.BlobTypeDescriptor$5.doExtract(BlobTypeDescriptor.java:115)
    at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:64)
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:254)
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:250)
    at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:230)
    at org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:331)

Firstly why are you using transaction while you are only fetching records from db??? and also can you post full stacktrace? — Vimal Bera, Nov 24 '14 at 06:47
Increase your heap memory. -Xms and -Xmx are the one's which you needed! — janasainik, Nov 24 '14 at 06:49
@hemanth This might be related to hibernate logging feature. So you can't be sure about that. Check this http://stackoverflow.com/questions/8487221/hibernate-java-lang-outofmemoryerror-java-heap-space — Vimal Bera, Nov 24 '14 at 06:51
it depends on the size that the query returns! ofcorse it also depends on the type of the content that is stored(BLOB,etc..) — janasainik, Nov 24 '14 at 06:58
Use Pagination feature and load more data on request, If you dnt have sufficient system memory. — Ankit Sharma, Nov 24 '14 at 07:00
@Hemanth What can I do to solve this problem because the table contains images too — MorganM, Nov 24 '14 at 07:00

score 2 · Answer 1 · answered Nov 24 '14 at 07:02

2

I think you should not load a large table into memory at one time, use pagination is a must.

answered Nov 24 '14 at 07:02

sanigo

625
4
14

How can i implement that in hibernate – MorganM Nov 24 '14 at 07:18

score 2 · Answer 2 · edited May 23 '17 at 12:12

2

You can use

Query sry=s.createQuery("from MyBean where flag='NP'")
.setFirstResult(start).setMaxResults(pageSize);

for pagination.

Or you can increase heap size

edited May 23 '17 at 12:12

Community

1
1

answered Nov 24 '14 at 07:38

xrcwrn

5,339
17
68
129

Then how to i compine the paginated results into one bean? – MorganM Nov 24 '14 at 08:31
If you are fetchin data only for dislpay purpose then you can use thsi – xrcwrn Nov 24 '14 at 08:59
You can use Pagination . – xrcwrn Nov 25 '14 at 07:40

Out of Memory Error in hibernate when querying a table with large data

2 Answers2