Java: How to print log before and after a method invocation?

Question

I am writing an application in Java using the playwright library. I've created some static methods, like performBankAccountDetail, that executes a certain navigation or just invokes some methods of the object "page".

 Page page = context.newPage();
 System.out.println("[+] - Account detail (start) "+dtf.format(now));
 HomePage.performBankAccountDetail(page);
 System.out.println("[+] - Account detail (end) "+dtf.format(now));

 System.out.println("[+] - Documents detail (start) "+dtf.format(now));
 DocumentsSequence.documentsVisualization(page);
 System.out.println("[+] - Documents detail (end) "+dtf.format(now));

On every invocation of performBankAccountDetail I have to print the time and date before and after the invocation.

In my code those two lines (print before and after) are repeated for several actions.

With this method I am repeating the same code except for a string. What is the best method to reduce the number of lines of same code in the described scenario?

Answer 1

If I understand your question correctly, you basically want aspect-oriented programming (for example a framework such as AspectJ). If you feel such a framework would be too heavy for your need, you can easily write such functionality for yourself using lambda's.

Something like this:

package com.myapp.aspect;

import java.util.function.Supplier;

public class MiniWrapper {

    public static void wrap(Runnable function) {
        System.out.println("Before invocation");
        function.run();
        System.out.println("After invocation");
    }


    public static <T> T wrap(Supplier<T> function) {
        System.out.println("Before invocation");
        T result = function.get();
        System.out.println("After invocation");
        return result;
    }
}

You can then use above class as follows:

package com.myapp;

import static com.myapp.aspect.MiniWrapper.*;

public class TestSO {

    public static void main(String[] args) {
        wrap(TestSO::someMethod);
        wrap(() -> someOtherMethod("Hello"));
        wrap(() -> someOtherMethod("Who are you?"));
        String result = wrap(()-> concatter("1","2","3"));
        System.out.println(result);
    }

    public static void someMethod() {
        System.out.println("Hello method!");
    }

    public static void someOtherMethod(String param) {
        System.out.println("Some Other method with param: " + param );
    }

    public static String concatter(String first, String second, String third) {
        return first + second + third;
    }
}

I think using a decent library would be the better way going forward.