CGLIB

<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>2.2.2</version>
</dependency>

public class SampleClass {
    public void test(){
        System.out.println("hello world");
    }
public static void main(String[] args) {
    Enhancer enhancer = new Enhancer();
    enhancer.setSuperclass(SampleClass.class);
    enhancer.setCallback(new MethodInterceptor() {
        @Override
        public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
            System.out.println("before method run...");
            Object result = proxy.invokeSuper(obj, args);
            System.out.println("after method run...");
            return result;
        }
    });
    SampleClass sample = (SampleClass) enhancer.create();
    sample.test();
}

}
public class SampleClass {

public String test(String input){

return "hello world";

}

}