Prevent Stack Overflow Exceptions

Let's have a look at this generator:

public static class OverflowingPerson {
    private final String name;
    private final OverflowingPerson next;

    @Generate
    public OverflowingPerson(
        @Use(NameGenerator.class) final String name,
        final OverflowingPerson next
    ) {
        this.name = name;
        this.next = next;
    }
}

Here a StackOverflowException would occur, because OverflowingPerson (next) is generated recursively.

There are two ways to fix this:

1. Use @Depth

The @Depth-annotation specifies what the maximum depth may be for a generated object.

@Generate
public OverflowingPerson(
    @Use(NameGenerator.class) final String name,
    @Depth(2) final OverflowingPerson next
) {
    // ...
}

A stack overflow exception would not occur now, because in the 2nd OverflowingPerson next is not generated, thus null.

2. Use multiple @Generate constructors

public static class OverflowingPerson {
    private final String name;
    private final OverflowingPerson next;

    @Generate
    public OverflowingPerson(
        @Use(NameGenerator.class) final String name,
        @Generate("next") final OverflowingPerson next
    ) {
        this.name = name;
        this.next = next;
    }

    @Generate("next")
    public OverflowingPerson(
        @Use(NameGenerator.class) final String name
    ) {
        this.name = name;
        this.next = null;
    }
}

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Last update: 2022-03-15