Java Reflection - Method.getParameters() Examples

package com.logicbig.example.method;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.util.Arrays;
import java.util.Map;
import java.util.Objects;

public class GetParametersExample {

    private static class Test {
        private <T extends Serializable> void process(int processorId, String processName,
                                                      Map<Byte, T> processParams) {}
    }

    public static void main(String... args) throws Exception {
        Method[] m = Test.class.getDeclaredMethods();
        for (Method method : m) {
            System.out.println("-- " + method + " --");
            Parameter[] parameters = method.getParameters();
            System.out.println("-- " + Arrays.toString(parameters) + " --");
            for (Parameter parameter : parameters) {
                System.out.println("-- " + parameter + " --");
                printParameter(parameter);
            }
        }
    }

    private static void printParameter(Parameter p) throws Exception {
        for (Method method : Parameter.class.getDeclaredMethods()) {
            String methodName = method.getName();
            if (methodName.startsWith("get")) {
                if (method.getParameterCount() > 0) {
                    continue;
                }
                if (method.canAccess(p)) {
                    if (!method.trySetAccessible()) {
                        System.err.println("trySEtAccessible fails " + method);
                        continue;
                    }
                }
                Object o = null;
                try {
                    o = method.invoke(p);
                } catch (Exception e) {
                    //System.err.println(e + " - " + method);
                }
                print("Parameter#" + methodName, o);
            }
        }
    }

    private static void print(String msg, Object val) {
        if (val != null && val.getClass().isArray()) {
            val = Arrays.toString((Object[]) val);
        } else {
            val = Objects.toString(val);
        }
        System.out.printf(" %s = %s%n", msg, val);
    }
}