Java reflection JSON launcher "discussion"

[Alex Armenteros]

Here i'm asking for your opinion about this code and possible improvements or errors you may see. (only limitation i'm aware of is i can't have multiple methods with the same name on the class), also don't know if this is the correct forum to post this, if not, please move the post accordingly please.

I've developed (i think) a function launcher from a JSON string
The Json string is something like this.

{
    "service": "ServiceClass",
    "method": "methodName",
    "params": [
        {
            "object1Member1": "value11",
            "object1Member2": "value21"
        },
        [
            {
                "object2Member1": "value210",
                "object2Member2": "value220"
            },
            {
                "object2Member1": "value211",
                "object2Member2": "value221"
            }
        ]
    ]
}

method specifies which method i want to execute, service specifies which class contains that method, and params contains the parameters for the method.

In this case i want to execute a method like this "public Object methodName(Object1 ob, List<Object2> ob)"

The launcher code is something like this.

Gson gson = new Gson();

		@SuppressWarnings("unchecked")
//Transform to java object
		HashMap<String, Object> map = gson.fromJson(val, HashMap.class);
//Get class
		String service = map.get("service").toString();
//Here we get the bean from spring context for the later invoke
		Object serv = getBeanFromContext(service);
//Get method
		String metodo = map.get("method").toString();
//Get parameters
		ArrayList par = (ArrayList) map.get("params");

		try {
			//Search method
			Class<?> cl = Class.forName(service);
			Method[] met = cl.getMethods();
			Method m = null;
			for (Method me : met) {
				if (me.getName().equals(metodo)) {
					m = me;
					break;
				}
			}
			if (m == null) {
				throw new NoSuchMethodException();
			}
//Get parameters of method
			Type[] gen = m.getGenericParameterTypes();
			if (gen.length != 0) {
//Parameters
				Object[] call = new Object[gen.length];
				int i = 0;
				for (Type clas : gen) {
//Turn parameter back to json to transform into correct object type
					String param = gson.toJson(par.get(i));
					call[i] = gson.fromJson(param, clas);

					i++;
				}
				Object result = m.invoke(serv, call);
				if (result != null)
					return result;
			} else {
//No parameters
				Object result = m.invoke(serv);
				if (result != null)
					return result;

			}

		} catch (NoSuchMethodException | SecurityException
				| ClassNotFoundException | IllegalAccessException
				| IllegalArgumentException | InvocationTargetException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

I hope you find this useful on the future, and thanks in advance for your answers.

[Stephan van Hulst]

Why are you suppressing unchecked warnings? You should be using properly parameterized types.

You might be interested in the JAX-B and JAX-WS specifications that deal with object to XML bindings and XML method invocation respectively.