Mysql deserialization Problem

geek · **Joined:** Wed Aug 27, 2003 3:09 am **Posts:** 17

The problem:
When I try to deserialize SimpleClusteringResult javabean from mysql database, the below stack trace is resulted. The same problem is avoided by replacing MySQL with PostgreSQL 7.2.

Also, I have tried to load the serialized object with JDBC code. Such object can be loaded correctly from the database and can be deserialized without problem.Thus I am sure that the following problem is not related to the object size(17kbytes).

The configuration to reproduce the problem:

Hibernate 2.0.2 and 2.0.3

J2sdk 1.4.2

mysql-connector-java-3.0.8-stable

Mysql 3.x

The SimpleClusteringResult javabean:

Code:

public class SimpleClusteringResult implements Serializable {
   protected int[][] clusterMembers;
   protected int[][] selectedAttrs;
   protected int[] outliers;
}

Stack trace:

Code:

hk.hku.csis.biosphere.webservices.buffer.PersistenceException: net.sf.hibernate.type.SerializationException: Could not deserialize a serializable property: 
   at hk.hku.csis.biosphere.webservices.buffer.DatabaseCompletedTaskBuffer.getCompletedTask(DatabaseCompletedTaskBuffer.java:82)
   at hk.hku.csis.biosphere.webservices.buffer.DatabaseCompletedTaskBuffer.main(DatabaseCompletedTaskBuffer.java:91)
Caused by: net.sf.hibernate.type.SerializationException: Could not deserialize a serializable property: 
   at net.sf.hibernate.type.SerializableType.fromBytes(SerializableType.java:75)
   at net.sf.hibernate.type.SerializableType.get(SerializableType.java:35)
   at net.sf.hibernate.type.NullableType.nullSafeGet(NullableType.java:59)
   at net.sf.hibernate.type.NullableType.nullSafeGet(NullableType.java:51)
   at net.sf.hibernate.type.AbstractType.hydrate(AbstractType.java:66)
   at net.sf.hibernate.loader.Loader.hydrate(Loader.java:419)
   at net.sf.hibernate.loader.Loader.loadFromResultSet(Loader.java:373)
   at net.sf.hibernate.loader.Loader.instanceNotYetLoaded(Loader.java:342)
   at net.sf.hibernate.loader.Loader.getRow(Loader.java:281)
   at net.sf.hibernate.loader.Loader.doFind(Loader.java:159)
   at net.sf.hibernate.loader.Loader.loadEntity(Loader.java:587)
   at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:42)
   at net.sf.hibernate.persister.EntityPersister.load(EntityPersister.java:396)
   at net.sf.hibernate.impl.SessionImpl.doLoad(SessionImpl.java:1889)
   at net.sf.hibernate.impl.SessionImpl.doLoadByClass(SessionImpl.java:1757)
   at net.sf.hibernate.impl.SessionImpl.load(SessionImpl.java:1688)
   at hk.hku.csis.biosphere.webservices.buffer.DatabaseCompletedTaskBuffer.getCompletedTask(DatabaseCompletedTaskBuffer.java:74)
   ... 1 more
Caused by: org.apache.commons.lang.SerializationException
   at org.apache.commons.lang.SerializationUtils.deserialize(SerializationUtils.java:170)
   at org.apache.commons.lang.SerializationUtils.deserialize(SerializationUtils.java:191)
   at net.sf.hibernate.type.SerializableType.fromBytes(SerializableType.java:72)
   ... 17 more
Caused by: java.io.EOFException
   at java.io.ObjectInputStream$PeekInputStream.readFully(ObjectInputStream.java:2165)
   at java.io.ObjectInputStream$BlockDataInputStream.readInts(ObjectInputStream.java:2786)
   at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1582)
   at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1271)
   at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1603)
   at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1271)
   at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1845)
   at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1769)
   at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1646)
   at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
   at java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
   at org.apache.commons.lang.SerializationUtils.deserialize(SerializationUtils.java:165)
   ... 19 more
Process terminated with exit code 0

DaGGeRRz · **Joined:** Fri Oct 10, 2003 10:14 am **Posts:** 7

I'm seeing the excact same problem with Hibernate 2.0.1 HSQLDB 1.7.1. JDK 1.4.2_01, while retrieving an array of strings. I'm not sure this is really a hibernate error, seems more like an error in commons-lang since this is where the EOFException occurs.

What's strange is that if I store just a string (instead of an array of strings), I get a StreamCorruptedException in SerializationUtils instead. When looking at the data from an SQL client, everything looks good.

Any clues to help us out? :)

Cheers,

Dag

DaGGeRRz · **Joined:** Fri Oct 10, 2003 10:14 am **Posts:** 7

DaGGeRRz wrote:

I'm seeing the excact same problem with Hibernate 2.0.1 HSQLDB 1.7.1. JDK 1.4.2_01, while retrieving an array of strings.

Same problem with Hibernate 2.0.3 as well.

DaGGeRRz · **Joined:** Fri Oct 10, 2003 10:14 am **Posts:** 7

...so sorry about bothering the Hibernate community. :)

Cheers,

Dag

JimDaues · **Joined:** Tue Oct 21, 2003 4:31 pm **Posts:** 1

I see the same traceback.
I am using Hibernate 2.03, MySQL 4.0.15
driver=org.gjt.mm.mysql.Driver
[tried com.mysql.jdbc.Driver, failed too]
this is within the context of Jboss 3.22.

my property is:
<property name="delegateBytes" column="INVOCATION" type="binary" length="1024" />

the property setter/getter in the Java object uses byte []
this property is mapped to a BLOB column in the table.

I also tried setter/getter that uses java.sql.Blob directly.
that did not throw an exception, but I could never retrieve
the data successfully after a persist. the blob always came back
empty.

In my example, the length of the byte array is over 255
but well under the 1024 limit.

DaGGeRRz · **Joined:** Fri Oct 10, 2003 10:14 am **Posts:** 7

JimDaues wrote:

I see the same traceback.
I am using Hibernate 2.03, MySQL 4.0.15
driver=org.gjt.mm.mysql.Driver
[tried com.mysql.jdbc.Driver, failed too]
this is within the context of Jboss 3.22.

my property is:
<property name="delegateBytes" column="INVOCATION" type="binary" length="1024" />

the property setter/getter in the Java object uses byte []
this property is mapped to a BLOB column in the table.

I also tried setter/getter that uses java.sql.Blob directly.
that did not throw an exception, but I could never retrieve
the data successfully after a persist. the blob always came back
empty.

In my example, the length of the byte array is over 255
but well under the 1024 limit.

Perhaps this is Hibernate, after all. I haven't really had time to do more research / debugging. In this specific instance - the binaries are all set and read by the same service and no other process touches it (+ low volume, so everything stays in cached in the session). This in combination with being far-from-critical makes it acceptable for us to wait for a HSQL or Hibernate fix, so we just haven't done anything about it yet.

Perhaps Gavin or one of the other contributors can comment?