001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
025
026/**
027 * <p>
028 * Checks that instance variable names conform to a specified pattern.
029 * </p>
030 * <ul>
031 * <li>
032 * Property {@code format} - Specifies valid identifiers. Default value is
033 * {@code "^[a-z][a-zA-Z0-9]*$"}.
034 * </li>
035 * <li>
036 * Property {@code applyToPublic} - Controls whether to apply the check to public member.
037 * Default value is {@code true}.
038 * </li>
039 * <li>
040 * Property {@code applyToProtected} - Controls whether to apply the check to protected member.
041 * Default value is {@code true}.
042 * </li>
043 * <li>
044 * Property {@code applyToPackage} - Controls whether to apply the check to package-private member.
045 * Default value is {@code true}.
046 * </li>
047 * <li>
048 * Property {@code applyToPrivate} - Controls whether to apply the check to private member.
049 * Default value is {@code true}.
050 * </li>
051 * </ul>
052 * <p>
053 * An example of how to configure the check is:
054 * </p>
055 * <pre>
056 * &lt;module name=&quot;MemberName&quot;/&gt;
057 * </pre>
058 * <p>Code Example:</p>
059 * <pre>
060 * class MyClass {
061 *   public int num1; // OK
062 *   protected int num2; // OK
063 *   final int num3 = 3; // OK
064 *   private int num4; // OK
065 *
066 *   static int num5; // ignored: not an instance variable
067 *   public static final int CONSTANT = 1; // ignored: not an instance variable
068 *
069 *   public int NUM1; // violation, name 'NUM1'
070 *                    // must match pattern '^[a-z][a-zA-Z0-9]*$'
071 *   protected int NUM2; // violation, name 'NUM2'
072 *                       // must match pattern '^[a-z][a-zA-Z0-9]*$'
073 *   final int NUM3; // violation, name 'NUM3'
074 *                   // must match pattern '^[a-z][a-zA-Z0-9]*$'
075 *   private int NUM4; // violation, name 'NUM4'
076 *                     // must match pattern '^[a-z][a-zA-Z0-9]*$'
077 * }
078 * </pre>
079 * <p>
080 * An example of how to configure the check for names that begin with
081 * {@code &quot;m&quot;}, followed by an upper case letter, and then letters
082 * and digits. Also, suppress the check from being applied to protected
083 * and package-private member:
084 * </p>
085 *
086 * <pre>
087 * &lt;module name=&quot;MemberName&quot;&gt;
088 *   &lt;property name=&quot;format&quot; value=&quot;^m[A-Z][a-zA-Z0-9]*$&quot;/&gt;
089 *   &lt;property name=&quot;applyToProtected&quot; value=&quot;false&quot;/&gt;
090 *   &lt;property name=&quot;applyToPackage&quot; value=&quot;false&quot;/&gt;
091 * &lt;/module&gt;
092 * </pre>
093 * <p>Code Example:</p>
094 * <pre>
095 * class MyClass {
096 *   public int num1; // violation, name 'num1'
097 *                    // must match pattern '^m[A-Z][a-zA-Z0-9]*$'
098 *   protected int num2; // OK
099 *   int num3; // OK
100 *   private int num4; // violation, name 'num4'
101 *                     // must match pattern '^m[A-Z][a-zA-Z0-9]*$'
102 * }
103 * </pre>
104 * <p>
105 * An example of how to suppress the check which is applied to
106 * public and private member:
107 * </p>
108 * <pre>
109 * &lt;module name=&quot;MemberName&quot;&gt;
110 *   &lt;property name=&quot;applyToPublic&quot; value=&quot;false&quot;/&gt;
111 *   &lt;property name=&quot;applyToPrivate&quot; value=&quot;false&quot;/&gt;
112 * &lt;/module&gt;
113 * </pre>
114 * <p>Code Example:</p>
115 * <pre>
116 * class MyClass {
117 *   public int NUM1; // OK
118 *   protected int NUM2; // violation, name 'NUM2'
119 *                       // must match pattern '^[a-z][a-zA-Z0-9]*$'
120 *   int NUM3; // violation, name 'NUM3'
121 *             // must match pattern '^[a-z][a-zA-Z0-9]*$'
122 *   private int NUM4; // OK
123 * }
124 * </pre>
125 *
126 * @since 3.0
127 */
128public class MemberNameCheck
129    extends AbstractAccessControlNameCheck {
130
131    /** Creates a new {@code MemberNameCheck} instance. */
132    public MemberNameCheck() {
133        super("^[a-z][a-zA-Z0-9]*$");
134    }
135
136    @Override
137    public int[] getDefaultTokens() {
138        return getRequiredTokens();
139    }
140
141    @Override
142    public int[] getAcceptableTokens() {
143        return getRequiredTokens();
144    }
145
146    @Override
147    public int[] getRequiredTokens() {
148        return new int[] {TokenTypes.VARIABLE_DEF};
149    }
150
151    @Override
152    protected final boolean mustCheckName(DetailAST ast) {
153        final DetailAST modifiersAST =
154            ast.findFirstToken(TokenTypes.MODIFIERS);
155        final boolean isStatic = modifiersAST.findFirstToken(TokenTypes.LITERAL_STATIC) != null;
156
157        return !isStatic && !ScopeUtil.isInInterfaceOrAnnotationBlock(ast)
158            && !ScopeUtil.isLocalVariableDef(ast)
159                && shouldCheckInScope(modifiersAST);
160    }
161
162}