Question

I am beginner with Java, and I would like to write some code like this :

TEST(myfunction(1, 2, 3));

Where TEST is :

• Either a macro as used in C
• Either a function which need the address of the function myfunction

In my code, I would like TEST to do some code :

TEST(function) {
    if (function()) 
        // code
    else
        //code
}

I know pointers are not usable in Java.
An idea to help me ?

[EDIT]
Here is another example :

TEST(myfunction(1, 2, 3));

Where TEST is implemented :

void TEST (function(args[])) {
try {
    function();
}
catch (Exception e) {
    // Exception happened !
}

}

Thanks to that, with only one code line, I will be able to use try catch !

Answer 1

Java doesn’t have pointers to functions. The typical way functions are passed around in Java is to pass an object that implements Runnable.

EDIT: I’ve revised my example to be closer to your second case.

In your case, where you want a boolean return value, you can define your own interface:

public interface BooleanTest {
    boolean test(Object... args) throws Exception;
}

and then later:

class MyTest implements BooleanTest {
    private boolean result;
    public MyTest(int a, int b, int c) {
        result = a + b == c;
    }
    // stupid test -- don't _have_ to declare "throws Exception"
    public boolean test(Object... args) {
        return result && args.length == 3;
    }
}

TEST(new MyTest(1, 2, 3));

and inside TEST:

TEST(BooleanTest test) {
    try {
        if (test.test("Jack", "and", "Jill")) {
            // ...
        }
    } catch (Exception e) {
    }
}