oracle.jdbc.ReadTimeout for oracle.sql.CLOB.getChars

we often have this stuck thread on oracle.sql.CLOB.getChars:

####<Jan 6, 2014 10:34:39 AM CET> <Error> <WebLogicServer> <hqchacme110> <osbpr1ms3> <[ACTIVE] ExecuteThread: '19' for queue:
'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <d1a7b26be2c41106:7f955c62:143498f1087:-8000-00000000001dcb6a> <1389
000879486> <BEA-000337> <[STUCK] ExecuteThread: '15' for queue: 'weblogic.kernel.Default (self-tuning)' has been busy for "708"
seconds working on the request "weblogic.work.SelfTuningWorkManagerImpl$WorkAdapterImpl@16c083ce", which is more than the conf
igured time (StuckThreadMaxTime) of "600" seconds. Stack trace:
        java.net.SocketInputStream.socketRead0(Native Method)
        java.net.SocketInputStream.read(SocketInputStream.java:129)
        oracle.net.nt.MetricsEnabledInputStream.read(TcpNTAdapter.java:718)
        oracle.net.ns.Packet.receive(Packet.java:295)
        oracle.net.ns.DataPacket.receive(DataPacket.java:106)
        oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:317)
        oracle.net.ns.NetInputStream.read(NetInputStream.java:262)
        oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:107)
        oracle.jdbc.driver.T4CMAREngine.getNBytes(T4CMAREngine.java:1579)
        oracle.jdbc.driver.T4C8TTILobd.unmarshalLobData(T4C8TTILobd.java:455)
        oracle.jdbc.driver.T4C8TTILob.readLOBD(T4C8TTILob.java:796)
        oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:389)
        oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:204)
        oracle.jdbc.driver.T4C8TTIClob.read(T4C8TTIClob.java:245)
        oracle.jdbc.driver.T4CConnection.getChars(T4CConnection.java:3630)
        oracle.sql.CLOB.getChars(CLOB.java:756)
        oracle.sql.CLOB.getSubString(CLOB.java:398)
        weblogic.jdbc.wrapper.Clob_oracle_sql_CLOB.getSubString(Unknown Source)
        oracle.tip.adapter.db.sp.oracle.TypeConverter.toString(TypeConverter.java:241)
        oracle.tip.adapter.db.sp.oracle.TypeConverter.toString(TypeConverter.java:275)
        oracle.tip.adapter.db.sp.oracle.XMLBuilder.DOM(XMLBuilder.java:198)
        oracle.tip.adapter.db.sp.AbstractXMLBuilder.buildDOM(AbstractXMLBuilder.java:264)
        oracle.tip.adapter.db.sp.SPInteraction.executeStoredProcedure(SPInteraction.java:148)
        oracle.tip.adapter.db.DBInteraction.executeStoredProcedure(DBInteraction.java:1102)
        oracle.tip.adapter.db.DBInteraction.execute(DBInteraction.java:247)
        oracle.tip.adapter.sa.impl.fw.wsif.jca.WSIFOperation_JCA.performOperation(WSIFOperation_JCA.java:529)
        oracle.tip.adapter.sa.impl.fw.wsif.jca.WSIFOperation_JCA.executeOperation(WSIFOperation_JCA.java:353)
        oracle.tip.adapter.sa.impl.fw.wsif.jca.WSIFOperation_JCA.executeReque

at the same time on the Oracle DB side we have:

Fatal NI connect error 12170.

  VERSION INFORMATION:
        TNS for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production
        TCP/IP NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production
        Oracle Bequeath NT Protocol Adapter for IBM/AIX RISC System/6000: Version 11.2.0.3.0 - Production
  Time: 06-JAN-2014 10:22:25
  Tracing not turned on.
  Tns error struct:
    ns main err code: 12535

TNS-12535: TNS:operation timed out
    ns secondary err code: 12560
    nt main err code: 505

TNS-00505: Operation timed out
    nt secondary err code: 78
    nt OS err code: 0
  Client address: (ADDRESS=(PROTOCOL=tcp)(HOST=10.56.34.53)(PORT=1125))
Mon Jan 06 10:23:48 2014

I will try to fix this by setting the property oracle.jdbc.ReadTimeout to 1 800 000 (milliseconds = 30 minutes)