How do I get @ParametersAreNonnullByDefault to work?

how to apply@ParametersAreNonnullByDefault

package-info.javaCreate a file in your package in which to enforce the desired behavior.

In that file, do the following:

/**
 * You should do it like this!
 */
@ParametersAreNonnullByDefault
package com.stackoverflow;

import javax.annotation.ParametersAreNonnullByDefault;

How not to apply@ParametersAreNonnullByDefault

Do not do the following in a Java source file:

/**
 * But you shouldn't do it this way!
 */
@ParametersAreNonnullByDefault
package com.stackoverflow;

import javax.annotation.ParametersAreNonnullByDefault;

public class Answer { ...

Declaring such an annotation is ambiguous.

notes

Annotations can be applied directly on Answerclasses .

package com.stackoverflow;

import javax.annotation.ParametersAreNonnullByDefault;

/**
 * You can do it like this also.
 */
@ParametersAreNonnullByDefault
public class Answer { ...

The exact same thing applies .@ParametersAreNullableByDefault