[CAMEL-18865] camel-main - Setters not invoked on bean that implements Map

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.20.0
• Fix Version/s: 3.20.2, 3.21.0, 4.0-M1, 4.0.0
• Component/s: camel-main

Environment

jdk11, camel-main, camel-jms, IBM-MQ 9.2 (https://mvnrepository.com/artifact/com.ibm.mq/com.ibm.mq.allclient)

• Estimated Complexity: Unknown
• Assignee: Claus Ibsen
• Reporter: Christian Schubert-Huff
• Created: 06/Jan/23 09:42
• Updated: 30/Jan/23 08:59
• Resolved: 06/Jan/23 11:54

Description

We are having trouble configuring camel-jms with IBM-MQ as runtime implementation, using camel-main.

Doing so requires the declaration of a connection factory, which, in our case, is com.ibm.mq.jms.MQConnectionFactory. Unfortunately, this class implements both javax.jms.ConnectionFactory and java.util.Map<java.lang.String,java.lang.Object>. Also, the setters of that class have side effects, that are non-trivial to reproduce.

What was really troubling us was that, contrary to intuition, defining a bean like this:

camel.beans.mqConnectionFactory = #class:com.ibm.mq.jms.MQConnectionFactory
camel.beans.mqConnectionFactory.hostName = mqhost

does not actually invoke the setHostName method on the factory. Instead, value "mqhost" is put under key "hostName" into the map.

Reproduction can be achieved with a quick custom class, like this:

package org.apache.camel.main;

import java.util.HashMap;

public class MyFooFactory extends HashMap<String, Object> {
    private String hostName;

    public String getHostName() {
        return hostName;
    }

    public void setHostName(String hostName) {
        this.hostName = hostName;
    }
}

and a unit test, which checks for the hostName:

    @Test
    public void testBindBeansDottedHybridMap() {
        Main main = new Main();
        main.configure().addRoutesBuilder(new MyRouteBuilder());

        // defining a factory bean
        main.addProperty("camel.beans.myfactory", "#class:org.apache.camel.main.MyFooFactory");
        main.addProperty("camel.beans.myfactory.hostName", "localhost");
        main.start();

        CamelContext camelContext = main.getCamelContext();
        assertNotNull(camelContext);

        Object bean = camelContext.getRegistry().lookupByName("myfactory");
        assertNotNull(bean);
        assertInstanceOf(MyFooFactory.class, bean);

        MyFooFactory factory = (MyFooFactory) bean;
        assertEquals("localhost", factory.getHostName());

        main.stop();
    }

For a custom bean that is under our own control, I would consider implementing java.util.Map and having additional custom getters and setters with side-effects to be invalid, but the IBM-MQ JMS client is out of our control - and required for our use case.

If the dotted annotation is used, it may be preferable to check for a suitable setter first, and only if that is missing, to check if the bean implements java.util.Map.