org.sonar.java.checks.HasNextCallingNextCheck Maven / Gradle / Ivy
/*
* SonarQube Java
* Copyright (C) 2012-2024 SonarSource SA
* mailto:info AT sonarsource DOT com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the Sonar Source-Available License Version 1, as published by SonarSource SA.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the Sonar Source-Available License for more details.
*
* You should have received a copy of the Sonar Source-Available License
* along with this program; if not, see https://sonarsource.com/license/ssal/
*/
package org.sonar.java.checks;
import java.util.Collections;
import java.util.List;
import org.sonar.check.Rule;
import org.sonar.java.model.ExpressionUtils;
import org.sonar.plugins.java.api.IssuableSubscriptionVisitor;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.semantic.Type;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.MethodInvocationTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.Tree.Kind;
@Rule(key = "S1849")
public class HasNextCallingNextCheck extends IssuableSubscriptionVisitor {
private HasNextBodyVisitor hasNextBodyVisitor = new HasNextBodyVisitor();
@Override
public List nodesToVisit() {
return Collections.singletonList(Tree.Kind.METHOD);
}
@Override
public void visitNode(Tree tree) {
MethodTree methodTree = (MethodTree) tree;
if (methodTree.block() != null && isHasNextMethod(methodTree)) {
hasNextBodyVisitor.setHasNextOwner(methodTree.symbol().owner());
methodTree.block().accept(hasNextBodyVisitor);
}
}
@Override
public void setContext(JavaFileScannerContext context) {
super.setContext(context);
hasNextBodyVisitor.clearHasNextOwner();
}
@Override
public void leaveFile(JavaFileScannerContext context) {
hasNextBodyVisitor.clearHasNextOwner();
}
private static boolean isHasNextMethod(MethodTree methodTree) {
return "hasNext".equals(methodTree.simpleName().name()) && methodTree.parameters().isEmpty() && isIteratorMethod(methodTree.symbol());
}
private static boolean isIteratorMethod(Symbol method) {
Type type = method.owner().enclosingClass().type();
return !type.is("java.util.Iterator") && type.isSubtypeOf("java.util.Iterator");
}
private class HasNextBodyVisitor extends BaseTreeVisitor {
private Symbol hasNextOwner;
@Override
public void visitMethodInvocation(MethodInvocationTree tree) {
Symbol method = tree.methodSymbol();
if ("next".equals(method.name())
&& tree.arguments().isEmpty()
&& isIteratorMethod(method)
&& (hasNextOwner == method.owner() || hasNextOwner.type().isSubtypeOf(method.owner().type()))) {
reportIssue(ExpressionUtils.methodName(tree), "Refactor the implementation of this \"Iterator.hasNext()\" method to not call \"Iterator.next()\".");
}
super.visitMethodInvocation(tree);
}
public void setHasNextOwner(Symbol hasNextOwner) {
this.hasNextOwner = hasNextOwner;
}
public void clearHasNextOwner() {
this.hasNextOwner = null;
}
@Override
public void visitClass(ClassTree tree) {
// Don't visit nested classes
}
}
}
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