NonRuntimeAnnotation
Calling getAnnotation on an annotation that is not retained at runtime.

Category
JDK
Severity
ERROR
Maturity

The problem

Calling getAnnotation on an annotation that does not have its Retention set to RetentionPolicy.RUNTIME will always return null.

Suppression

Suppress false positives by adding an @SuppressWarnings("NonRuntimeAnnotation") annotation to the enclosing element.


Positive examples

NonRuntimeAnnotationPositiveCases.java

/*
 * Copyright 2012 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.errorprone.bugpatterns.testdata;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;


/**
 * @author scottjohnson@google.com (Scott Johnsson)
 */
@NonRuntimeAnnotationPositiveCases.NotSpecified
@NonRuntimeAnnotationPositiveCases.NonRuntime
public class NonRuntimeAnnotationPositiveCases {

  public NonRuntime testAnnotation() {
    // BUG: Diagnostic contains: null
    NonRuntimeAnnotationPositiveCases.class.getAnnotation(
        NonRuntimeAnnotationPositiveCases.NonRuntime.class);
    // BUG: Diagnostic contains: null
    NonRuntimeAnnotationPositiveCases.class.getAnnotation(
        NonRuntimeAnnotationPositiveCases.NotSpecified.class);
    // BUG: Diagnostic contains: null
    return this.getClass().getAnnotation(NonRuntimeAnnotationPositiveCases.NonRuntime.class);
  }

  /**
   * Annotation that is explicitly NOT retained at runtime
   */
  @Retention(RetentionPolicy.SOURCE)
  public @interface NonRuntime {
  }
  
  /**
   * Annotation that is implicitly NOT retained at runtime
   */
  public @interface NotSpecified {
  }
}

Negative examples

NonRuntimeAnnotationNegativeCases.java

/*
 * Copyright 2012 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.errorprone.bugpatterns.testdata;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;

/**
 * @author scottjohnson@google.com (Scott Johnsson)
 */
@NonRuntimeAnnotationNegativeCases.Runtime
public class NonRuntimeAnnotationNegativeCases {

  public Runtime testAnnotation() {
    return this.getClass().getAnnotation(NonRuntimeAnnotationNegativeCases.Runtime.class);
  }

  /**
   * Annotation that is retained at runtime
   */
  @Retention(RetentionPolicy.RUNTIME)
  public @interface Runtime {
  }
}