1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.sizes;
21
22 import com.puppycrawl.tools.checkstyle.StatelessCheck;
23 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
24 import com.puppycrawl.tools.checkstyle.api.DetailAST;
25 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
26
27 /**
28 * <p>
29 * Checks for long anonymous inner classes.
30 * </p>
31 * <p>
32 * Rationale: If an anonymous inner class becomes very long
33 * it is hard to understand and to see the flow of the method
34 * where the class is defined. Therefore, long anonymous inner
35 * classes should usually be refactored into a named inner class.
36 * See also Bloch, Effective Java, p. 93.
37 * </p>
38 * <ul>
39 * <li>
40 * Property {@code max} - Specify the maximum number of lines allowed.
41 * Type is {@code int}.
42 * Default value is {@code 20}.
43 * </li>
44 * </ul>
45 * <p>
46 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
47 * </p>
48 * <p>
49 * Violation Message Keys:
50 * </p>
51 * <ul>
52 * <li>
53 * {@code maxLen.anonInner}
54 * </li>
55 * </ul>
56 *
57 * @since 3.2
58 */
59 @StatelessCheck
60 public class AnonInnerLengthCheck extends AbstractCheck {
61
62 /**
63 * A key is pointing to the warning message text in "messages.properties"
64 * file.
65 */
66 public static final String MSG_KEY = "maxLen.anonInner";
67
68 /** Default maximum number of lines. */
69 private static final int DEFAULT_MAX = 20;
70
71 /** Specify the maximum number of lines allowed. */
72 private int max = DEFAULT_MAX;
73
74 @Override
75 public int[] getDefaultTokens() {
76 return getRequiredTokens();
77 }
78
79 @Override
80 public int[] getAcceptableTokens() {
81 return getRequiredTokens();
82 }
83
84 @Override
85 public int[] getRequiredTokens() {
86 return new int[] {TokenTypes.LITERAL_NEW};
87 }
88
89 @Override
90 public void visitToken(DetailAST ast) {
91 final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
92 if (openingBrace != null) {
93 final DetailAST closingBrace =
94 openingBrace.findFirstToken(TokenTypes.RCURLY);
95 final int length =
96 closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
97 if (length > max) {
98 log(ast, MSG_KEY, length, max);
99 }
100 }
101 }
102
103 /**
104 * Setter to specify the maximum number of lines allowed.
105 *
106 * @param length the maximum length of an anonymous inner class.
107 * @since 3.2
108 */
109 public void setMax(int length) {
110 max = length;
111 }
112
113 }