How to return user defines class in JMX? - jmx

Question

I am new to JMX and now I wished to monitor my project with JMX. Is there any way to return user defined class via MBeans/MXBean? I know that OpentType can help but don't know how to used it. I also went through Composite and Tabular data types but it may not work for me because I need to convert each and every class into respective data types.
Please provide your help.
Thank you in advance!!

Answer 1

You have to create an Interface SomethingMBean and a class that implement that interface.
public interface HelloMBean {
public void sayHello();
public int add(int x, int y);
public String getName();
public int getCacheSize();
public void setCacheSize(int size);
}
public class Hello ...
implements HelloMBean {
public void sayHello() {
System.out.println("hello, world");
}
public int add(int x, int y) {
return x + y;
}
public String getName() {
return this.name;
}
public int getCacheSize() {
return this.cacheSize;
}
public synchronized void setCacheSize(int size) {
...
this.cacheSize = size;
System.out.println("Cache size now " + this.cacheSize);
}
...
private final String name = "Reginald";
private int cacheSize = DEFAULT_CACHE_SIZE;
private static final int
DEFAULT_CACHE_SIZE = 200;
}
And then, you have to register your MBean...
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
ObjectName name = new ObjectName("com.example:type=Hello");
Hello mbean = new Hello();
mbs.registerMBean(mbean, name);
Take a look at Java Tutorial

Answer 2

If your project is using Spring, then it is quite easy to expose any user-defined class to JMX by simply using annotations:
#ManagedResource - to expose the class to JMX
#ManagedAttribute - to expose any fields of a ManagedResource class as attributes
#ManagedOperation - to expose any method of a ManagedResource class
as an operation
Have a look at the official Spring documentation which contains quite a few illustrative examples as well.