Question

For example, I have this code:

// ...
for (int i = 0; i < 5000; ++i) {
    for (int j = 0; j < 7000; ++j) {
        // Do something...
    }
}
// ...

Can I change it using annotations? If yes, how I can perform it? Something like this:

// ...
@SplitFor(value="i < 2000, j < 3000")
for (int i = 0; i < 5000; ++i) {
    for (int j = 0; j < 7000; ++j) {
        // Do something...
    }
}
// ...

Should translate to:

// ...
for (int i = 0; i < 2000; ++i) {
    for (int j = 0; j < 3000; ++j) {
        // Do something...
    }
}
// ...

It possible? If yes — HOW?

P.S.:
This is can used for easy parallelization: I can generate split loops for used it in Fork/Join framework, for example.

Answer 1

Typically, you’d do this in one of two ways:

1. An annotation processor, which would see the annotation, and alter the class code
2. Aspectj, which could find the annotation, and do runtime weaving of code, though i’m not sure what capability it would have of doing a block replace of code. typically people use this for before/after/around advice not for replacing code.