[AMQ-5632] MapMessage.getBytes crashes with NPE if no value present

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 5.12.0
• Assignee: Timothy A. Bish
• Reporter: Endre Stølsvik
• Created: 03/Mar/15 14:27
• Updated: 03/Mar/15 21:18
• Resolved: 03/Mar/15 21:18

Description

Compare to AMQ-5628 and AMQ-5629

Read up on http://docs.oracle.com/javaee/1.4/api/javax/jms/MapMessage.html

Notice the wording "if there is no item by this name, a null value is returned."

ActiveMqMapMessage, line ~494:

    /**
     * Returns the byte array value with the specified name.
     *
     * @param name the name of the byte array
     * @return a copy of the byte array value with the specified name; if there
     *         is no item by this name, a null value is returned.
     * @throws JMSException if the JMS provider fails to read the message due to
     *                 some internal error.
     * @throws MessageFormatException if this type conversion is invalid.
     */
    @Override
    public byte[] getBytes(String name) throws JMSException {
        initializeReading();
        Object value = map.get(name);
        if (value instanceof byte[]) {
            return (byte[])value;
        } else {
            throw new MessageFormatException(" cannot read a byte[] from " + value.getClass().getName());
        }
    }

Notice how the "else"-block will kick in on null value, whereby we get the "value.getClass()" executed when inside the constructor argument creation of the wrongly thrown MessageFormatException, resulting in NPE.

Instead, a code block like every other getter has should be employed, here from getString right above:

    public String getString(String name) throws JMSException {
        initializeReading();
        Object value = map.get(name);
        if (value == null) {
            return null;
        }
        if (value instanceof byte[]) {
            throw new MessageFormatException("Use getBytes to read a byte array");
        } else {
            return value.toString();
        }
    }

Notice the null-check with null-return.

Issue Links

• relates to: AMQ-5628 MapMessage.getDouble uses Float when converting from String/UTF8
• relates to: AMQ-5629 MapMessage.getChar does not handle if the backing map contains String or UTF8