ArrayIndexOutOfBoundsException when using saveDataGraph

In my project, for every service call response, I need to use saveDataGraph to translate Datagraph to XML string. So I have a function called bind:

public static String bind( final DataGraph graph ) throws IOException
{
if ( graph != null && graph.getRootObject() != null )

{ ByteArrayOutputStream os = new ByteArrayOutputStream(); Map<String, Object> options = new HashMap<String, Object>(); options.put( "DECLARE_XML", Boolean.FALSE ); SDOUtil.saveDataGraph( graph, os, options ); final String xml = os.toString(); return xml; }

return null;
}

This works fine most of the time. However, if I have too many service calls, which in turn calls the bind function for too many times, the following problem happens. It seems saveDataGraph has some problem in clearing out the buffer?

java.lang.ArrayIndexOutOfBoundsException: 8192
at org.eclipse.emf.ecore.xmi.impl.StringSegment.writeAscii(StringSegment.java:322)
at org.eclipse.emf.ecore.xmi.impl.XMLSaveImpl.writeAscii(XMLSaveImpl.java:900)
at org.eclipse.emf.ecore.xmi.impl.XMLSaveImpl.save(XMLSaveImpl.java:237)
at org.eclipse.emf.ecore.xmi.impl.XMLResourceImpl.doSave(XMLResourceImpl.java:203)
at org.eclipse.emf.ecore.resource.impl.ResourceImpl.save(ResourceImpl.java:993)
at org.apache.tuscany.sdo.helper.SDOHelperImpl.saveDataGraph(SDOHelperImpl.java:220)
at org.apache.tuscany.sdo.api.SDOUtil.saveDataGraph(SDOUtil.java:175)
at com.abacus.aim.service.util.DataGraphUtils.bind(DataGraphUtils.java:80)
at com.abacus.aim.service.translation.LookupQueryTranslation.processRequest(LookupQueryTranslation.java:57)
at com.abacus.aim.service.translation.ServiceTranslation.process(ServiceTranslation.java:113)
at sun.reflect.GeneratedMethodAccessor364.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:275)
at org.springframework.jms.listener.adapter.MessageListenerAdapter.invokeListenerMethod(MessageListenerAdapter.java:452)
at org.springframework.jms.listener.adapter.MessageListenerAdapter.onMessage(MessageListenerAdapter.java:354)
at org.springframework.jms.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:506)
at org.springframework.jms.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:463)
at org.springframework.jms.listener.AbstractMessageListenerContainer.doExecuteListener(AbstractMessageListenerContainer.java:435)
at org.springframework.jms.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:407)
at org.springframework.jms.listener.SimpleMessageListenerContainer.processMessage(SimpleMessageListenerContainer.java:228)
at org.springframework.jms.listener.SimpleMessageListenerContainer$2.onMessage(SimpleMessageListenerContainer.java:205)
at org.apache.activemq.ActiveMQMessageConsumer.dispatch(ActiveMQMessageConsumer.java:946)
at org.apache.activemq.ActiveMQSessionExecutor.dispatch(ActiveMQSessionExecutor.java:122)
at org.apache.activemq.ActiveMQSessionExecutor.iterate(ActiveMQSessionExecutor.java:192)
at org.apache.activemq.thread.PooledTaskRunner.runTask(PooledTaskRunner.java:118)
at org.apache.activemq.thread.PooledTaskRunner$1.run(PooledTaskRunner.java:42)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:675)
at java.lang.Thread.run(Thread.java:595)

Thank you very much for your help!!