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.whitespace;
021
022import com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
027import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
028
029/**
030 * <p>Checks that chosen statements are not line-wrapped.
031 * By default this Check restricts wrapping import and package statements,
032 * but it's possible to check any statement.
033 * </p>
034 * <ul>
035 * <li>
036 * Property {@code tokens} - tokens to check
037 * Default value is:
038 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#PACKAGE_DEF">
039 * PACKAGE_DEF</a>,
040 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#IMPORT">
041 * IMPORT</a>,
042 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#STATIC_IMPORT">
043 * STATIC_IMPORT</a>.
044 * </li>
045 * </ul>
046 * <p>Examples of line-wrapped statements (bad case):
047 * </p>
048 * <pre>
049 * package com.puppycrawl. // violation
050 *     tools.checkstyle.checks;
051 *
052 * import com.puppycrawl.tools. // violation
053 *     checkstyle.api.AbstractCheck;
054 *
055 * import static java.math. // violation
056 *     BigInteger.ZERO;
057 * </pre>
058 *
059 * <p>
060 * To configure the check to force no line-wrapping
061 * in package and import statements (default values):
062 * </p>
063 * <pre>
064 * &lt;module name=&quot;NoLineWrap&quot;/&gt;
065 * </pre>
066 * <p>
067 * Examples:
068 * </p>
069 * <pre>
070 * package com.puppycrawl.tools.checkstyle. // violation
071 *   checks.whitespace;
072 *
073 * import java.lang.Object; // OK
074 * import java.lang. // violation
075 *   Integer;
076 *
077 * import static java.math. // violation
078 *   BigInteger.TEN;
079 * </pre>
080 * <pre>
081 * package com.puppycrawl.tools.checkstyle.checks.coding; // OK
082 *
083 * import java.lang. // violation
084 *   Boolean;
085 *
086 * import static java.math.BigInteger.ONE; // OK
087 * </pre>
088 *
089 * <p>
090 * To configure the check to force no line-wrapping only
091 * in import statements:
092 * </p>
093 * <pre>
094 * &lt;module name=&quot;NoLineWrap&quot;&gt;
095 *   &lt;property name="tokens" value="IMPORT"/&gt;
096 * &lt;/module&gt;
097 * </pre>
098 * <p>
099 * Example:
100 * </p>
101 * <pre>
102 * package com.puppycrawl. // OK
103 *   tools.checkstyle.checks;
104 *
105 * import java.io.*; // OK
106 * import java.lang. // violation
107 *  Boolean;
108 *
109 * import static java.math. // OK
110 * BigInteger.ZERO;
111 * </pre>
112 * <p>
113 * To configure the check to force no line-wrapping only
114 * in class, method and constructor definitions:
115 * </p>
116 * <pre>
117 * &lt;module name=&quot;NoLineWrap&quot;&gt;
118 *   &lt;property name="tokens" value="CLASS_DEF, METHOD_DEF, CTOR_DEF"/&gt;
119 * &lt;/module&gt;
120 * </pre>
121 * <p>
122 * Example:
123 * </p>
124 * <pre>
125 * public class // violation, class definition not wrapped in a single line
126 *   Foo {
127 *
128 *   public Foo() { // OK
129 *   }
130 *
131 *   public static void // violation, method definition not wrapped in a single line
132 *     doSomething() {
133 *   }
134 * }
135 *
136 * public class Bar { // OK
137 *
138 *   public // violation, constructor definition not wrapped in a single line
139 *     Bar() {
140 *   }
141 *
142 *   public int fun() { // OK
143 *   }
144 * }
145 * </pre>
146 *
147 * <p>Examples of not line-wrapped statements (good case):
148 * </p>
149 * <pre>
150 * import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
151 * import static java.math.BigInteger.ZERO;
152 * </pre>
153 *
154 * @since 5.8
155 */
156@StatelessCheck
157public class NoLineWrapCheck extends AbstractCheck {
158
159    /**
160     * A key is pointing to the warning message text in "messages.properties"
161     * file.
162     */
163    public static final String MSG_KEY = "no.line.wrap";
164
165    @Override
166    public int[] getDefaultTokens() {
167        return new int[] {TokenTypes.PACKAGE_DEF, TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT};
168    }
169
170    @Override
171    public int[] getAcceptableTokens() {
172        return new int[] {
173            TokenTypes.IMPORT,
174            TokenTypes.STATIC_IMPORT,
175            TokenTypes.PACKAGE_DEF,
176            TokenTypes.CLASS_DEF,
177            TokenTypes.METHOD_DEF,
178            TokenTypes.CTOR_DEF,
179            TokenTypes.ENUM_DEF,
180            TokenTypes.INTERFACE_DEF,
181        };
182    }
183
184    @Override
185    public int[] getRequiredTokens() {
186        return CommonUtil.EMPTY_INT_ARRAY;
187    }
188
189    @Override
190    public void visitToken(DetailAST ast) {
191        if (!TokenUtil.areOnSameLine(ast, ast.getLastChild())) {
192            log(ast, MSG_KEY, ast.getText());
193        }
194    }
195
196}