How to get the body of a byte message in JMS ActiveMQ Artemis?

Question

I have a code that gets a message from a JMS queue, but I don't understand how to get the body of the message if it is a byte and translate it into a String:

connectQueueBrowser();
Enumeration<Message> messageEnumeration =  queueBrowser.getEnumeration();
ArrayList<Message> messages = new ArrayList<>();
while (messageEnumeration.hasMoreElements()){
   messages.add(messageEnumeration.nextElement());
}
System.out.println(messages.get(0).getBody(String.class));

This is the error I get:

javax.jms.MessageFormatException: Body not assignable to class java.lang.String

But I get an error when I display body messages.

Answer 1

If you have sent a JMS BytesMessage then you can only use getBody with byte[].class, e.g.:

System.out.println(messages.get(0).getBody(byte[].class));

If you've serialized a Java String into the BytesMessage using something like this:

bytesMessage.writeBytes(myString.getBytes(StandardCharsets.UTF_8));

Then you'll be able to deserialize that String from the BytesMessage using something like this:

byte[] myBytes = new byte[(int)bytesMessage.getBodyLength()];
bytesMessage.readBytes(myBytes);      
String myString = new String(myBytes, StandardCharsets.UTF_8);