OverridesJavaxInjectableMethod
This method is not annotated with @Inject, but it overrides a method that is annotated with @javax.inject.Inject. The method will not be Injected.

Category
Severity
ERROR
Maturity

The problem

When classes declare that they have an @javax.inject.Injected method, dependency injection tools must call those methods after first calling any @javax.inject.Inject constructor, and performing any field injection. These methods are part of the initialization contract for the object.

When subclasses override methods annotated with @javax.inject.Inject and don’t also annotate themselves with @javax.inject.Inject, the injector will not call those methods as part of the subclass’s initialization. This may unexpectedly cause assumptions taken in the superclass (e.g.: this post-initialization routine is finished, meaning that I can safely use this field) to no longer hold.

This compile error is intended to prevent this unintentional breaking of assumptions. Possible resolutions to this error include:

Suppression

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


Positive examples

OverridesJavaxInjectableMethodPositiveCases.java

/*
 * Copyright 2013 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.inject.guice.testdata;

/**
 * @author sgoldfeder@gooogle.com (Steven Goldfeder)
 */
public class OverridesJavaxInjectableMethodPositiveCases {

  /** Class with foo() */
  public class TestClass0 {
    public void foo() {}
  }

  /**
   * Class with a method foo() that is annotated with {@code javax.inject.Inject}. Other test
   * classes will extend this class.
   */
  public class TestClass1 extends TestClass0 {
    @javax.inject.Inject
    public void foo() {}
  }

  /**
   * Class with a method foo() that is not annotated, but overrides a method annotated with
   * @javax.inject.Inject.
   */
  public class TestClass2 extends TestClass1 {
    // BUG: Diagnostic contains: @Inject
    public void foo() {}
  }
  
  /**
   * Class with a method foo() that is not annotated, but overrides a method that in turn overrides
   * a method that is annotated with @javax.inject.Inject.
   */
  public class TestClass3 extends TestClass2 {
    // BUG: Diagnostic contains: @Inject
    public void foo() {}
  }
}

Negative examples

OverridesJavaxInjectableMethodNegativeCases.java

/*
 * Copyright 2013 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.inject.guice.testdata;

/** @author sgoldfeder@gooogle.com (Steven Goldfeder) */
public class OverridesJavaxInjectableMethodNegativeCases {
  /** Class with a method foo() with no annotations. */
  public class TestClass1 {
    public void foo() {}
  }

  /** Class with a method foo() annotated with @com.google.inject.Inject. */
  public class TestClass2 {
    @com.google.inject.Inject
    public void foo() {}
  }

  /** Class with a method foo() annotated with @javax.inject.Inject. */
  public class TestClass3 {
    @javax.inject.Inject
    public void foo() {}
  }

  /** OK, as it overrides a Guice-Inject method */
  public class TestClass4 extends TestClass2 {
    @Override
    public void foo() {}
  }

  /** gInject <- jInject */
  public class TestClass5 extends TestClass3 {
    @com.google.inject.Inject
    public void foo() {}
  }

  /** jInject <- gInject */
  public class TestClass6 extends TestClass2 {
    @javax.inject.Inject
    public void foo() {}
  }

  /** OK, as 7 <- jInject <- gInject */
  public class TestClass7 extends TestClass6 {
    public void foo() {}
  }

  /** OK, as 8 <- gInject */
  public class TestClass8 extends TestClass5 {
    public void foo() {}
  }

  /** Explicitly suppressed warning */
  public class TestClass9 extends TestClass3 {
    @Override
    @SuppressWarnings("OverridesJavaxInjectableMethod")
    public void foo() {}
  }
}