How do I write a hint for Netbeans?

Question

I have looked everywhere, and the only example I could find was one for marking JOptionPane.show and removing it. That doesn't help me much.

Answer 1

Note: This goes over making a hint that will match a method, but when you are done, you should be able to match more (like learning RegEx)

This was rather difficult to do and figure out... I am going to assume you have gone over the tutorial at https://platform.netbeans.org/tutorials/nbm-java-hint.html. After creating the hint via the instructions there, you now have a basic Hint implementation:

@Hint(displayName = "#DN_MainCallHint", description = "#DESC_MainCallHint",
        category = "general")
        @Messages({
    "DN_MainCallHint=MainCall",
    "DESC_MainCallHint=Warns the user when they are manually calling public "
            + "static void main"
})
public class MainCallHint {
    @TriggerPattern(value = "$str.equals(\"\")", //Specify a pattern as needed
            constraints = @ConstraintVariableType(variable = "$str", type
                    = "java.lang.String"))
    @Messages("ERR_MainCallHint=Directly calling main! Did you mean to do that?")
    public static ErrorDescription computeWarning(HintContext ctx) {
        return ErrorDescriptionFactory.forName(ctx, ctx.getPath(), Bundle.
                ERR_MainCallHint());
    }
}

The main trouble I had was with @TriggerPattern.value. If you wanted to match a method call, you would set it to something like this:

"$caller.method($arg1, $arg2)"

and can set type constraints for each of those variables. One important thing to note: if you are trying to match a static method of a particular type, use the FQN of that class or it won't work with arguments. So use something like this:

"test.HintTest.main($args)"

Resulting in the @TriggerPattern bit to look like this:

@TriggerPattern(value = "test.HintTest.main($args)", //Specify a pattern as needed
            constraints = @ConstraintVariableType(variable = "$args", type
                    = "java.lang.String[]"))

And you get this:

Now, the tutorial shows a very cumbersome way to implement a fix. If all you need to do is a simple replace, then it can be done like this:

public static ErrorDescription computeWarning(HintContext ctx) {
    Fix fix = JavaFixUtilities.rewriteFix(ctx, "Use notMain instead",
            ctx.getPath(), "test.HintTest.notMain($args)");
    return ErrorDescriptionFactory.forName(ctx, ctx.getPath(), Bundle.
            ERR_MainCallHint(), fix);
}

Note: The variables used for rewriteFix must be the same you used in @TriggerPattern or they will be interpreted as literals.