1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 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 * <div>
29 * Checks for long anonymous inner classes.
30 * </div>
31 *
32 * <p>
33 * Rationale: If an anonymous inner class becomes very long
34 * it is hard to understand and to see the flow of the method
35 * where the class is defined. Therefore, long anonymous inner
36 * classes should usually be refactored into a named inner class.
37 * See also Bloch, Effective Java, p. 93.
38 * </p>
39 *
40 * @since 3.2
41 */
42 @StatelessCheck
43 public class AnonInnerLengthCheck extends AbstractCheck {
44
45 /**
46 * A key is pointing to the warning message text in "messages.properties"
47 * file.
48 */
49 public static final String MSG_KEY = "maxLen.anonInner";
50
51 /** Default maximum number of lines. */
52 private static final int DEFAULT_MAX = 20;
53
54 /** Specify the maximum number of lines allowed. */
55 private int max = DEFAULT_MAX;
56
57 /**
58 * Creates a new {@code AnonInnerLengthCheck} instance.
59 */
60 public AnonInnerLengthCheck() {
61 // no code by default
62 }
63
64 @Override
65 public int[] getDefaultTokens() {
66 return getRequiredTokens();
67 }
68
69 @Override
70 public int[] getAcceptableTokens() {
71 return getRequiredTokens();
72 }
73
74 @Override
75 public int[] getRequiredTokens() {
76 return new int[] {TokenTypes.LITERAL_NEW};
77 }
78
79 @Override
80 public void visitToken(DetailAST ast) {
81 final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
82 if (openingBrace != null) {
83 final DetailAST closingBrace =
84 openingBrace.findFirstToken(TokenTypes.RCURLY);
85 final int length =
86 closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
87 if (length > max) {
88 log(ast, MSG_KEY, length, max);
89 }
90 }
91 }
92
93 /**
94 * Setter to specify the maximum number of lines allowed.
95 *
96 * @param length the maximum length of an anonymous inner class.
97 * @since 3.2
98 */
99 public void setMax(int length) {
100 max = length;
101 }
102
103 }