readStringOfCharLength(int length) throws EOF exception

I have written below code to read more than one messages in IBM MQ

com.ibm.mq.MQQueue defaultLocalQueue;
MQQueueManager qManager=null;
MQEnvironment.hostname = "reese.int.westgroup.com";
MQEnvironment.channel = "CLIENTCONNECTION";
MQEnvironment.port = 1414;
String qMngrStr = "";
qManager = new MQQueueManager(qMngrStr); 
int openOptions = MQC.MQOO_INPUT_AS_Q_DEF | MQC.MQOO_OUTPUT | MQC.MQOO_INQUIRE ; 
String queueName="COMSERV.SRCHEXT.EVENTS.PUBLISH.QA.Q01";
System.out.println("accessing::"+queueName);
defaultLocalQueue = qManager.accessQueue(queueName, openOptions);
//set transport properties.
System.out.println("set MQ props");
MQEnvironment.properties.put(MQC.TRANSPORT_PROPERTY, MQC.TRANSPORT_MQSERIES_CLIENT);
System.out.println("new Queuemanager");
ArrayList<MQMessage> msg = new ArrayList<MQMessage>();
//MQMessage putMessage = new MQMessage();
//String msg = "hello";
// putMessage.writeUTF(msg);
//specify the message options...
// MQPutMessageOptions pmo = new MQPutMessageOptions(); 
// accept 
// put the message on the queue
//defaultLocalQueue.put(putMessage, pmo);
boolean getMore = true;
while(getMore)
{  
MQMessage getMessages= new MQMessage();
MQGetMessageOptions gmo = new MQGetMessageOptions();
gmo.options=MQC.MQGMO_WAIT;
gmo.waitInterval=1000000;
//gmo.wait(100000);
System.out.println("get messages::"+gmo.toString());
defaultLocalQueue.get(getMessages, gmo);
msg.add(getMessages);
int length=getMessages.getMessageLength();
System.out.println("length::"+length);
String retrievedMsg = getMessages.readStringOfCharLength(length);
System.out.println("Message got from MQ: "+retrievedMsg);
}
if(defaultLocalQueue.getCurrentDepth()==0)
{
getMore=false;
}
for (MQMessage message : msg)
{
System.out.println("message::"+message);
}
}

The line

String retrievedMsg = getMessages.readStringOfCharLength(length); 

is causing an EOF exception even though the messages are there in MQ and length of the message is also printing 3760.

Below is the complete stack trace of the exception.

length::3760
java.io.EOFException: MQJE086: End of file exception ('MQMessage.readChar()').
at com.ibm.mq.MQMessage.readChar(MQMessage.java:908)
at com.ibm.mq.MQMessage.readStringOfCharLength(MQMessage.java:1232)
at com.tlr.searchextract.messages.MessageTrigger_ABean.init(MessageTrigger_ABean.java:109)
at com.tlr.searchextract.servlet.SEControllerServlet.insertRequestTemplate(SEControllerServlet.java:1385)
at com.tlr.searchextract.servlet.SEControllerServlet.performTask(SEControllerServlet.java:2055)
at com.tlr.searchextract.servlet.SEControllerServlet.doPost(SEControllerServlet.java:117)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:203)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)

Please help me with this.

From the MQMessage in the MQ KnowLedge Center:

> getMessageLength() Gets the number of bytes of message data in this
> message.

So, one method deals in bytes then you use readStringOfCharLength method which deals in characters.

FYI: byte length != character length

You should be using readStringOfByteLength method.

i.e.

int length=getMessages.getMessageLength();
String retrievedMsg = getMessages.readStringOfByteLength(length);

Updated: August 19, 2020.

If MQ cannot convert the message to a string then you can get it as a byte array and have the JVM attempt to convert it to a string.

int length=getMessages.getMessageLength();
byte[] bMsg = new byte[length];
getMessages.readFully(bMsg);
String retrievedMsg = new String(bMsg);

This is documented in Printing the content of a message using IBM® MQ classes for Java:

import com.ibm.mq.MQMessage;
import com.ibm.mq.headers.MQHeaderList;
...
MQMessage message = ... // Message received from a queue.
System.out.println (new MQHeaderList (message, true));