/*
* 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;
import static com.google.errorprone.BugPattern.Category.GUICE;
import static com.google.errorprone.BugPattern.MaturityLevel.EXPERIMENTAL;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.matchers.Matchers.hasAnnotation;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.Matchers;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.MethodTree;
import com.sun.tools.javac.code.Attribute.Compound;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import javax.lang.model.element.TypeElement;
/**
* This checker matches methods that
* 1) are not themselves annotated with @Inject
* (neither javax.inject.Inject nor com.google.inject.Inject)
* 2) descend from a method that is annotated with @com.google.inject.Inject
*
* @author sgoldfeder@google.com (Steven Goldfeder)
*/
@BugPattern(name = "OverridesGuiceInjectableMethod", summary =
"This method is not annotated with @Inject, but it overrides a "
+ "method that is annotated with @com.google.inject.Inject. Guice will inject this method,"
+ "and it is recommended to annotate it explicitly.",
explanation =
"Unlike with @javax.inject.Inject, if a method overrides a method annoatated with "
+ "@com.google.inject.Inject, Guice will inject it even if it itself is not annotated. "
+ "This differs from the behavior of methods that override @javax.inject.Inject methods "
+ "since according to the JSR-330 spec, a method that overrides a method annotated with "
+ "javax.inject.Inject will not be injected unless it iself is annotated with @Inject. "
+ "Because of this difference, it is recommended that you annotate this method explicitly.",
category = GUICE, severity = WARNING, maturity = EXPERIMENTAL)
public class GuiceOverridesGuiceInjectableMethod extends BugChecker implements MethodTreeMatcher {
private static final String OVERRIDE_ANNOTATION = "java.lang.Override";
private static final String GUICE_INJECT_ANNOTATION = "com.google.inject.Inject";
private static final String JAVAX_INJECT_ANNOTATION = "javax.inject.Inject";
private static final Matcher<MethodTree> INJECTABLE_METHOD_MATCHER = Matchers.<MethodTree>anyOf(
hasAnnotation(GUICE_INJECT_ANNOTATION), hasAnnotation(JAVAX_INJECT_ANNOTATION));
private static final Matcher<MethodTree> OVERRIDE_METHOD_MATCHER =
Matchers.<MethodTree>hasAnnotation(OVERRIDE_ANNOTATION);
@Override
public Description matchMethod(MethodTree methodTree, VisitorState state) {
// if method is itself annotated with @Inject or it has no ancestor methods, return No_MATCH;
if (!INJECTABLE_METHOD_MATCHER.matches(methodTree, state)
&& OVERRIDE_METHOD_MATCHER.matches(methodTree, state)) {
MethodSymbol method = (MethodSymbol) ASTHelpers.getSymbol(methodTree);
MethodSymbol superMethod = null;
for (boolean checkSuperClass = true; checkSuperClass; method = superMethod) {
superMethod = ASTHelpers.findSuperMethod(method, state.getTypes());
if (isAnnotatedWith(superMethod, GUICE_INJECT_ANNOTATION)) {
return describeMatch(methodTree, SuggestedFix.builder()
.addImport("javax.inject.Inject")
.prefixWith(methodTree, "@Inject\n")
.build());
}
checkSuperClass = isAnnotatedWith(superMethod, OVERRIDE_ANNOTATION);
}
}
return Description.NO_MATCH;
}
private static boolean isAnnotatedWith(MethodSymbol method, String annotation) {
for (Compound c : method.getAnnotationMirrors()) {
if (((TypeElement) c.getAnnotationType().asElement()).getQualifiedName()
.contentEquals(annotation)) {
return true;
}
}
return false;
}
}