1 /*
2 * Copyright (c) 2011-2024 Qulice.com
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met: 1) Redistributions of source code must retain the above
9 * copyright notice, this list of conditions and the following
10 * disclaimer. 2) Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials provided
13 * with the distribution. 3) Neither the name of the Qulice.com nor
14 * the names of its contributors may be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
20 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
22 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
25 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
27 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
29 * OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 package com.qulice.checkstyle;
32
33 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
34 import com.puppycrawl.tools.checkstyle.api.DetailAST;
35 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
36 import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
37 import java.util.ArrayDeque;
38 import java.util.Deque;
39 import org.cactoos.text.Joined;
40 import org.cactoos.text.UncheckedText;
41
42 /**
43 * Checks that classes are declared as final. Doesn't check for classes nested
44 * in interfaces or annotations, as they are always {@code final} there.
45 * <p>
46 * An example of how to configure the check is:
47 * </p>
48 * <pre>
49 * <module name="ProhibitNonFinalClassesCheck"/>
50 * </pre>
51 *
52 * @since 0.19
53 */
54 public final class ProhibitNonFinalClassesCheck extends AbstractCheck {
55
56 /**
57 * Character separate package names in qualified name of java class.
58 */
59 private static final String PACKAGE_SEPARATOR = ".";
60
61 /**
62 * Keeps ClassDesc objects for stack of declared classes.
63 */
64 private Deque<ClassDesc> classes = new ArrayDeque<>();
65
66 /**
67 * Full qualified name of the package.
68 */
69 private String pack;
70
71 @Override
72 public int[] getDefaultTokens() {
73 return this.getRequiredTokens();
74 }
75
76 @Override
77 public int[] getAcceptableTokens() {
78 return this.getRequiredTokens();
79 }
80
81 @Override
82 public int[] getRequiredTokens() {
83 return new int[] {TokenTypes.CLASS_DEF};
84 }
85
86 @Override
87 public void beginTree(final DetailAST root) {
88 this.classes = new ArrayDeque<>();
89 this.pack = "";
90 }
91
92 @Override
93 public void visitToken(final DetailAST ast) {
94 final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
95 if (ast.getType() == TokenTypes.CLASS_DEF) {
96 final boolean isfinal =
97 modifiers.findFirstToken(TokenTypes.FINAL) != null;
98 final boolean isabstract =
99 modifiers.findFirstToken(TokenTypes.ABSTRACT) != null;
100 final String qualified = this.qualifiedClassName(ast);
101 this.classes.push(
102 new ClassDesc(qualified, isfinal, isabstract)
103 );
104 }
105 }
106
107 @Override
108 public void leaveToken(final DetailAST ast) {
109 if (ast.getType() == TokenTypes.CLASS_DEF) {
110 final ClassDesc desc = this.classes.pop();
111 if (!desc.isDeclaredAsAbstract()
112 && !desc.isAsfinal()
113 && !ScopeUtil.isInInterfaceOrAnnotationBlock(ast)) {
114 final String qualified = desc.getQualified();
115 final String name =
116 ProhibitNonFinalClassesCheck.getClassNameFromQualifiedName(
117 qualified
118 );
119 log(ast.getLineNo(), "Classes should be final", name);
120 }
121 }
122 }
123
124 /**
125 * Get qualified class name from given class Ast.
126 * @param classast Class to get qualified class name
127 * @return Qualified class name of a class
128 */
129 private String qualifiedClassName(final DetailAST classast) {
130 final String name = classast.findFirstToken(
131 TokenTypes.IDENT
132 ).getText();
133 String outer = null;
134 if (!this.classes.isEmpty()) {
135 outer = this.classes.peek().getQualified();
136 }
137 return ProhibitNonFinalClassesCheck.getQualifiedClassName(
138 this.pack,
139 outer,
140 name
141 );
142 }
143
144 /**
145 * Calculate qualified class name(package + class name) laying inside given
146 * outer class.
147 * @param pack Package name, empty string on default package
148 * @param outer Qualified name(package + class) of outer
149 * class, null if doesn't exist
150 * @param name Class name
151 * @return Qualified class name(package + class name)
152 */
153 private static String getQualifiedClassName(
154 final String pack,
155 final String outer,
156 final String name) {
157 final String qualified;
158 if (outer == null) {
159 if (pack.isEmpty()) {
160 qualified = name;
161 } else {
162 qualified =
163 new UncheckedText(
164 new Joined(
165 ProhibitNonFinalClassesCheck.PACKAGE_SEPARATOR,
166 pack,
167 name
168 )
169 ).asString();
170 }
171 } else {
172 qualified =
173 new UncheckedText(
174 new Joined(
175 ProhibitNonFinalClassesCheck.PACKAGE_SEPARATOR,
176 outer,
177 name
178 )
179 ).asString();
180 }
181 return qualified;
182 }
183
184 /**
185 * Get class name from qualified name.
186 * @param qualified Qualified class name
187 * @return Class Name
188 */
189 private static String getClassNameFromQualifiedName(
190 final String qualified
191 ) {
192 return qualified.substring(
193 qualified.lastIndexOf(
194 ProhibitNonFinalClassesCheck.PACKAGE_SEPARATOR
195 ) + 1
196 );
197 }
198
199 /**
200 * Maintains information about class' ctors.
201 *
202 * @since 0.1
203 */
204 private static final class ClassDesc {
205
206 /**
207 * Qualified class name(with package).
208 */
209 private final String qualified;
210
211 /**
212 * Is class declared as final.
213 */
214 private final boolean asfinal;
215
216 /**
217 * Is class declared as abstract.
218 */
219 private final boolean asabstract;
220
221 /**
222 * Create a new ClassDesc instance.
223 *
224 * @param qualified Qualified class name(with package)
225 * @param asfinal Indicates if the class declared as final
226 * @param asabstract Indicates if the class declared as
227 * abstract
228 */
229 ClassDesc(final String qualified, final boolean asfinal,
230 final boolean asabstract
231 ) {
232 this.qualified = qualified;
233 this.asfinal = asfinal;
234 this.asabstract = asabstract;
235 }
236
237 /**
238 * Get qualified class name.
239 * @return Qualified class name
240 */
241 private String getQualified() {
242 return this.qualified;
243 }
244
245 /**
246 * Is class declared as final.
247 * @return True if class is declared as final
248 */
249 private boolean isAsfinal() {
250 return this.asfinal;
251 }
252
253 /**
254 * Is class declared as abstract.
255 * @return True if class is declared as final
256 */
257 private boolean isDeclaredAsAbstract() {
258 return this.asabstract;
259 }
260 }
261 }