GuiceInjectOnFinalField
Although Guice allows injecting final fields, doing so is disallowed because the injected value may not be visible to other threads.

Severity
ERROR
Has Fix?
REQUIRES_HUMAN_ATTENTION

The problem

See https://github.com/google/guice/wiki/InjectionPoints#how-guice-injects

Suppression

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


Positive examples

InjectOnFinalFieldPositiveCases.java

/*
* Copyright 2013 The Error Prone Authors.
*
* 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;

import com.google.inject.Inject;
import javax.annotation.Nullable;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
public class InjectOnFinalFieldPositiveCases {
/** Class has a final injectable(com.google.inject.Inject) field. */
public class TestClass1 {
// BUG: Diagnostic contains: @Inject int a
@Inject final int a = 0;

@Inject
// BUG: Diagnostic contains: public int b
public final int b = 0;

@Inject @Nullable
// BUG: Diagnostic contains: Object c
final Object c = null;
}
}

Negative examples

InjectOnFinalFieldNegativeCases.java

/*
* Copyright 2013 The Error Prone Authors.
*
* 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;

import com.google.inject.Inject;

/** @author sgoldfeder@google.com (Steven Goldfeder) */
public class InjectOnFinalFieldNegativeCases {

/** Class has no final fields or @Inject annotations. */
public class TestClass1 {}

/** Class has a final field that is not injectable. */
public class TestClass2 {
public final int n = 0;
}

/** Class has an injectable(com.google.inject.Inject) field that is not final. */
public class TestClass3 {
@Inject public int n;
}

/** Class has an injectable(com.google.inject.Inject), final method. */
public class TestClass4 {
@Inject
final void method() {}
}
}