001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.metrics;
021
022import java.util.regex.Pattern;
023
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * <div>
028 * Measures the number of distinct classes that are instantiated
029 * within the given class or record. This type of coupling is not caused by inheritance or
030 * the object-oriented paradigm. Generally speaking, any data type with other
031 * data types as members or local variable that is an instantiation (object)
032 * of another class has data abstraction coupling (DAC). The higher the DAC,
033 * the more complex the structure of the class.
034 * </div>
035 *
036 * <p>
037 * This check processes files in the following way:
038 * </p>
039 * <ol>
040 * <li>
041 * Iterates over the list of tokens (defined below) and counts all mentioned classes.
042 * <ul>
043 * <li>
044 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#IMPORT">
045 * PACKAGE_DEF</a>
046 * </li>
047 * <li>
048 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#IMPORT">
049 * IMPORT</a>
050 * </li>
051 * <li>
052 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CLASS_DEF">
053 * CLASS_DEF</a>
054 * </li>
055 * <li>
056 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#INTERFACE_DEF">
057 * INTERFACE_DEF</a>
058 * </li>
059 * <li>
060 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#ENUM_DEF">
061 * ENUM_DEF</a>
062 * </li>
063 * <li>
064 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#LITERAL_NEW">
065 * LITERAL_NEW</a>
066 * </li>
067 * <li>
068 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RECORD_DEF">
069 * RECORD_DEF</a>
070 * </li>
071 * </ul>
072 * </li>
073 * <li>
074 * If a class was imported with direct import (i.e. {@code import java.math.BigDecimal}),
075 * or the class was referenced with the package name (i.e. {@code java.math.BigDecimal value})
076 * and the package was added to the {@code excludedPackages} parameter, the class
077 * does not increase complexity.
078 * </li>
079 * <li>
080 * If a class name was added to the {@code excludedClasses} parameter,
081 * the class does not increase complexity.
082 * </li>
083 * </ol>
084 *
085 * @since 3.4
086 */
087public final class ClassDataAbstractionCouplingCheck
088    extends AbstractClassCouplingCheck {
089
090    /**
091     * A key is pointing to the warning message text in "messages.properties" file.
092     */
093    public static final String MSG_KEY = "classDataAbstractionCoupling";
094
095    /** Default allowed complexity. */
096    private static final int DEFAULT_MAX = 7;
097
098    /** Creates bew instance of the check. */
099    public ClassDataAbstractionCouplingCheck() {
100        super(DEFAULT_MAX);
101    }
102
103    @Override
104    public int[] getRequiredTokens() {
105        return new int[] {
106            TokenTypes.PACKAGE_DEF,
107            TokenTypes.IMPORT,
108            TokenTypes.CLASS_DEF,
109            TokenTypes.INTERFACE_DEF,
110            TokenTypes.ENUM_DEF,
111            TokenTypes.LITERAL_NEW,
112            TokenTypes.RECORD_DEF,
113        };
114    }
115
116    @Override
117    public int[] getAcceptableTokens() {
118        return getRequiredTokens();
119    }
120
121    @Override
122    protected String getLogMessageId() {
123        return MSG_KEY;
124    }
125
126    /**
127     * Setter to specify user-configured regular expressions to ignore classes.
128     *
129     * @param from array representing regular expressions of classes to ignore.
130     * @propertySince 7.7
131     */
132    @Override
133    public void setExcludeClassesRegexps(Pattern... from) {
134        super.setExcludeClassesRegexps(from);
135    }
136
137    /**
138     * Setter to specify user-configured class names to ignore.
139     *
140     * @param excludedClasses classes to ignore.
141     * @propertySince 5.7
142     */
143    @Override
144    public void setExcludedClasses(String... excludedClasses) {
145        super.setExcludedClasses(excludedClasses);
146    }
147
148    /**
149     * Setter to specify user-configured packages to ignore.
150     *
151     * @param excludedPackages packages to ignore.
152     * @throws IllegalArgumentException if there are invalid identifiers among the packages.
153     * @propertySince 7.7
154     */
155    @Override
156    public void setExcludedPackages(String... excludedPackages) {
157        super.setExcludedPackages(excludedPackages);
158    }
159
160}