Web Article - ClassLoader Example

package com.jcg;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

/**
 * @author ashraf
 * 
 */
public class JavaClassLoader extends ClassLoader {
 
 public void invokeClassMethod(String classBinName, String methodName){
  
  try {
   
   // Create a new JavaClassLoader 
   ClassLoader classLoader = this.getClass().getClassLoader();
   
   // Load the target class using its binary name
         Class loadedMyClass = classLoader.loadClass(classBinName);
         
         System.out.println("Loaded class name: " + loadedMyClass.getName());
         
         // Create a new instance from the loaded class
         Constructor constructor = loadedMyClass.getConstructor();
         Object myClassObject = constructor.newInstance();
         
         // Getting the target method from the loaded class and invoke it using its name
         Method method = loadedMyClass.getMethod(methodName);
         System.out.println("Invoked method name: " + method.getName());
         method.invoke(myClassObject);

  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (Exception e) {
   e.printStackTrace();
  }
  
 }
}

Running the example

package com.jcg;


/**
 * @author ashraf
 * 
 */
public class ClassLoaderTest extends JavaClassLoader {

 public static void main(String[] args) {

  JavaClassLoader javaClassLoader = new JavaClassLoader();
  javaClassLoader.invokeClassMethod("com.jcg.MyClass", "sayHello");
  
 }
 
}

Source: javacodegeeks