ClassFanOutComplexityCheck.java
///////////////////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
// Copyright (C) 2001-2024 the original author or authors.
//
// This library 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 2.1 of the License, or (at your option) any later version.
//
// This library 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 library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
///////////////////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.metrics;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
/**
* <p>
* Checks the number of other types a given class/record/interface/enum/annotation
* relies on. Also, the square of this has been shown to indicate the amount
* of maintenance required in functional programs (on a file basis) at least.
* </p>
* <p>
* This check processes files in the following way:
* </p>
* <ol>
* <li>
* Iterates over all tokens that might contain type reference.
* </li>
* <li>
* If a class was imported with direct import (i.e. {@code import java.math.BigDecimal}),
* or the class was referenced with the package name (i.e. {@code java.math.BigDecimal value})
* and the package was added to the {@code excludedPackages} parameter,
* the class does not increase complexity.
* </li>
* <li>
* If a class name was added to the {@code excludedClasses} parameter,
* the class does not increase complexity.
* </li>
* </ol>
* <ul>
* <li>
* Property {@code excludeClassesRegexps} - Specify user-configured regular
* expressions to ignore classes.
* Type is {@code java.util.regex.Pattern[]}.
* Default value is {@code ^$}.
* </li>
* <li>
* Property {@code excludedClasses} - Specify user-configured class names to ignore.
* Type is {@code java.lang.String[]}.
* Default value is {@code ArrayIndexOutOfBoundsException, ArrayList, Boolean, Byte,
* Character, Class, Collection, Deprecated, Deque, Double, DoubleStream, EnumSet, Exception,
* Float, FunctionalInterface, HashMap, HashSet, IllegalArgumentException, IllegalStateException,
* IndexOutOfBoundsException, IntStream, Integer, LinkedHashMap, LinkedHashSet, LinkedList, List,
* Long, LongStream, Map, NullPointerException, Object, Optional, OptionalDouble, OptionalInt,
* OptionalLong, Override, Queue, RuntimeException, SafeVarargs, SecurityException, Set, Short,
* SortedMap, SortedSet, Stream, String, StringBuffer, StringBuilder, SuppressWarnings, Throwable,
* TreeMap, TreeSet, UnsupportedOperationException, Void, boolean, byte, char, double,
* float, int, long, short, var, void}.
* </li>
* <li>
* Property {@code excludedPackages} - Specify user-configured packages to ignore.
* Type is {@code java.lang.String[]}.
* Default value is {@code ""}.
* </li>
* <li>
* Property {@code max} - Specify the maximum threshold allowed.
* Type is {@code int}.
* Default value is {@code 20}.
* </li>
* </ul>
* <p>
* Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
* </p>
* <p>
* Violation Message Keys:
* </p>
* <ul>
* <li>
* {@code classFanOutComplexity}
* </li>
* </ul>
*
* @since 3.4
*/
public final class ClassFanOutComplexityCheck extends AbstractClassCouplingCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "classFanOutComplexity";
/** Default value of max value. */
private static final int DEFAULT_MAX = 20;
/** Creates new instance of this check. */
public ClassFanOutComplexityCheck() {
super(DEFAULT_MAX);
}
@Override
public int[] getRequiredTokens() {
return new int[] {
TokenTypes.PACKAGE_DEF,
TokenTypes.IMPORT,
TokenTypes.CLASS_DEF,
TokenTypes.EXTENDS_CLAUSE,
TokenTypes.IMPLEMENTS_CLAUSE,
TokenTypes.ANNOTATION,
TokenTypes.INTERFACE_DEF,
TokenTypes.ENUM_DEF,
TokenTypes.TYPE,
TokenTypes.LITERAL_NEW,
TokenTypes.LITERAL_THROWS,
TokenTypes.ANNOTATION_DEF,
TokenTypes.RECORD_DEF,
};
}
@Override
public int[] getAcceptableTokens() {
return getRequiredTokens();
}
@Override
protected String getLogMessageId() {
return MSG_KEY;
}
}