RxInteropFunction.java

public class RxInteropFunction<T, R> implements Func1<T, R>, Function<T, R> {

    public static <T, R> RxInteropFunction<T, R> wrap(Function<T, R> function) {
        return new RxInteropFunction<>(function);
    }

    private final Function<T, R> function;

    private RxInteropFunction(Function<T, R> function) {
        this.function = function;
    }

    @Override
    public R apply(T t) throws Exception {
        return function.apply(t);
    }

    @Override
    public R call(T t) {
        try {
            return function.apply(t);
        } catch (Throwable throwable) {
            throw new RuntimeException(throwable);
        }
    }

}

RxInteropPredicate.java

public class RxInteropPredicate<T> implements Predicate<T>, Func1<T, Boolean> {

    public static <T> RxInteropPredicate<T> wrap(Predicate<T> predicate) {
        return new RxInteropPredicate<>(predicate);
    }

    private final Predicate<T> predicate;

    public RxInteropPredicate(Predicate<T> predicate) {
        this.predicate = predicate;
    }

    @Override
    public boolean test(T t) throws Exception {
        return predicate.test(t);
    }

    @Override
    public Boolean call(T t) {
        try {
            return predicate.test(t);
        } catch (Throwable throwable) {
            throw new RuntimeException(throwable);
        }
    }

}