/*
* SonarQube Java
* Copyright (C) 2012-2016 SonarSource SA
* mailto:contact AT sonarsource DOT com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* 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 GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package org.sonar.java.checks;
import com.google.common.collect.Sets;
import org.sonar.check.Rule;
import org.sonar.check.RuleProperty;
import org.sonar.plugins.java.api.JavaFileScanner;
import org.sonar.plugins.java.api.JavaFileScannerContext;
import org.sonar.plugins.java.api.tree.ArrayTypeTree;
import org.sonar.plugins.java.api.tree.BaseTreeVisitor;
import org.sonar.plugins.java.api.tree.CatchTree;
import org.sonar.plugins.java.api.tree.ClassTree;
import org.sonar.plugins.java.api.tree.ExpressionTree;
import org.sonar.plugins.java.api.tree.IdentifierTree;
import org.sonar.plugins.java.api.tree.InstanceOfTree;
import org.sonar.plugins.java.api.tree.MemberSelectExpressionTree;
import org.sonar.plugins.java.api.tree.MethodTree;
import org.sonar.plugins.java.api.tree.NewArrayTree;
import org.sonar.plugins.java.api.tree.NewClassTree;
import org.sonar.plugins.java.api.tree.ParameterizedTypeTree;
import org.sonar.plugins.java.api.tree.Tree;
import org.sonar.plugins.java.api.tree.TypeCastTree;
import org.sonar.plugins.java.api.tree.TypeParameterTree;
import org.sonar.plugins.java.api.tree.UnionTypeTree;
import org.sonar.plugins.java.api.tree.VariableTree;
import org.sonar.plugins.java.api.tree.WildcardTree;
import javax.annotation.Nullable;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
@Rule(key = "S1200")
public class ClassCouplingCheck extends BaseTreeVisitor implements JavaFileScanner {
private static final int DEFAULT_MAX = 20;
@RuleProperty(
key = "max",
description = "Maximum number of classes a single class is allowed to depend upon",
defaultValue = "" + DEFAULT_MAX)
public int max = DEFAULT_MAX;
private final Deque<Set<String>> nesting = new LinkedList<>();
private Set<String> types;
private JavaFileScannerContext context;
@Override
public void scanFile(JavaFileScannerContext context) {
this.context = context;
scan(context.getTree());
}
@Override
public void visitClass(ClassTree tree) {
if (tree.is(Tree.Kind.CLASS) && tree.simpleName() != null) {
nesting.push(types);
types = Sets.newHashSet();
}
checkTypes(tree.superClass());
checkTypes((List<? extends Tree>) tree.superInterfaces());
super.visitClass(tree);
if (tree.is(Tree.Kind.CLASS) && tree.simpleName() != null) {
if (types.size() > max) {
context.reportIssue(
this,
tree.simpleName(),
"Split this class into smaller and more specialized ones to reduce its dependencies on other classes from " +
types.size() + " to the maximum authorized " + max + " or less.");
}
types = nesting.pop();
}
}
@Override
public void visitVariable(VariableTree tree) {
checkTypes(tree.type());
super.visitVariable(tree);
}
@Override
public void visitCatch(CatchTree tree) {
//skip visit catch parameter for backward compatibility
scan(tree.block());
}
@Override
public void visitTypeCast(TypeCastTree tree) {
checkTypes(tree.type());
super.visitTypeCast(tree);
}
@Override
public void visitMethod(MethodTree tree) {
checkTypes(tree.returnType());
super.visitMethod(tree);
}
@Override
public void visitTypeParameter(TypeParameterTree typeParameter) {
checkTypes((List<? extends Tree>) typeParameter.bounds());
checkTypes(typeParameter.identifier());
super.visitTypeParameter(typeParameter);
}
@Override
public void visitUnionType(UnionTypeTree tree) {
// can not be visited because of visitCatch excluding exceptions
checkTypes((List<? extends Tree>) tree.typeAlternatives());
super.visitUnionType(tree);
}
@Override
public void visitParameterizedType(ParameterizedTypeTree tree) {
checkTypes(tree.type());
checkTypes((List<Tree>) tree.typeArguments());
super.visitParameterizedType(tree);
}
@Override
public void visitNewClass(NewClassTree tree) {
if (tree.typeArguments() != null) {
checkTypes((List<Tree>) tree.typeArguments());
}
if (tree.identifier().is(Tree.Kind.PARAMETERIZED_TYPE)) {
scan(tree.enclosingExpression());
checkTypes((List<Tree>) ((ParameterizedTypeTree) tree.identifier()).typeArguments());
scan(tree.typeArguments());
scan(tree.arguments());
scan(tree.classBody());
} else {
super.visitNewClass(tree);
}
}
@Override
public void visitWildcard(WildcardTree tree) {
checkTypes(tree.bound());
super.visitWildcard(tree);
}
@Override
public void visitArrayType(ArrayTypeTree tree) {
checkTypes(tree.type());
super.visitArrayType(tree);
}
@Override
public void visitInstanceOf(InstanceOfTree tree) {
checkTypes(tree.type());
super.visitInstanceOf(tree);
}
@Override
public void visitNewArray(NewArrayTree tree) {
checkTypes(tree.type());
super.visitNewArray(tree);
}
private void checkTypes(List<? extends Tree> types) {
for (Tree type : types) {
checkTypes(type);
}
}
private void checkTypes(@Nullable Tree type) {
if (type == null || types == null) {
return;
}
if (type.is(Tree.Kind.IDENTIFIER)) {
types.add(((IdentifierTree) type).name());
} else if (type.is(Tree.Kind.MEMBER_SELECT)) {
ExpressionTree expr = (ExpressionTree) type;
while (expr.is(Tree.Kind.MEMBER_SELECT)) {
MemberSelectExpressionTree mse = (MemberSelectExpressionTree) expr;
types.add(mse.identifier().name());
expr = mse.expression();
}
if (expr.is(Tree.Kind.IDENTIFIER)) {
types.add(((IdentifierTree) expr).name());
}
types.add(((MemberSelectExpressionTree) type).identifier().name());
}
}
}