/*
* 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.ERROR;
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;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Symbol.TypeSymbol;
import javax.lang.model.element.TypeElement;
/**
* This checker matches methods that
* 1) are not themselves annotated with @Inject
* 2) descend from a method that is annotated with @javax.inject.Inject
* 3) do not descent from a method that is annotated with @com.google.inject.Inject
*
* @author sgoldfeder@google.com (Steven Goldfeder)
*/
@BugPattern(name = "OverridesJavaxInjectableMethod",
summary = "This method is not annotated with @Inject, but it overrides a method that is "
+ " annotated with @javax.inject.Inject.",
explanation = "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",
category = GUICE, severity = ERROR, maturity = EXPERIMENTAL)
public class GuiceOverridesJavaxInjectableMethod 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)) {
return Description.NO_MATCH;
}
boolean foundJavaxInject = false;
MethodSymbol method = (MethodSymbol) ASTHelpers.getSymbol(methodTree);
MethodSymbol superMethod = null;
for (boolean checkSuperClass = true; checkSuperClass; method = superMethod) {
superMethod = findSuperMethod(method, state);
if (isAnnotatedWith(superMethod, GUICE_INJECT_ANNOTATION)) {
return Description.NO_MATCH;
}
// is not necessarily a match even if we find javax Inject on an ancestor
// since a higher up ancestor may have @com.google.inject.Inject
foundJavaxInject = isAnnotatedWith(superMethod, JAVAX_INJECT_ANNOTATION);
// check if there are ancestor methods
checkSuperClass = isAnnotatedWith(superMethod, OVERRIDE_ANNOTATION);
}
if (foundJavaxInject) {
return describeMatch(methodTree,
SuggestedFix.builder()
.addImport("javax.inject.Inject")
.prefixWith(methodTree, "@Inject\n")
.build());
}
return Description.NO_MATCH;
}
private MethodSymbol findSuperMethod(MethodSymbol method, VisitorState state) {
TypeSymbol superClass = method.enclClass().getSuperclass().tsym;
for (Symbol s : superClass.members().getElements()) {
if (s.name.contentEquals(method.name)
&& method.overrides(s, superClass, state.getTypes(), true)) {
return (MethodSymbol) s;
}
}
return null;
}
// better to use matchers?
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;
}
}