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.naming;
21
22 import com.puppycrawl.tools.checkstyle.api.DetailAST;
23 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24
25 /**
26 * <p>
27 * Checks that {@code catch} parameter names conform to a specified pattern.
28 * </p>
29 * <p>
30 * Default pattern has the following characteristic:
31 * </p>
32 * <ul>
33 * <li>allows names beginning with two lowercase letters followed by at least one uppercase or
34 * lowercase letter</li>
35 * <li>allows {@code e} abbreviation (suitable for exceptions end errors)</li>
36 * <li>allows {@code ex} abbreviation (suitable for exceptions)</li>
37 * <li>allows {@code t} abbreviation (suitable for throwables)</li>
38 * <li>allows {@code _} for unnamed catch parameters</li>
39 * <li>prohibits numbered abbreviations like {@code e1} or {@code t2}</li>
40 * <li>prohibits one letter prefixes like {@code pException}</li>
41 * <li>prohibits two letter abbreviations like {@code ie} or {@code ee}</li>
42 * <li>prohibits any other characters than letters</li>
43 * </ul>
44 * <ul>
45 * <li>
46 * Property {@code format} - Sets the pattern to match valid identifiers.
47 * Type is {@code java.util.regex.Pattern}.
48 * Default value is {@code "^(e|t|ex|[a-z][a-z][a-zA-Z]+|_)$"}.
49 * </li>
50 * </ul>
51 * <p>
52 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
53 * </p>
54 * <p>
55 * Violation Message Keys:
56 * </p>
57 * <ul>
58 * <li>
59 * {@code name.invalidPattern}
60 * </li>
61 * </ul>
62 *
63 * @since 6.14
64 */
65 public class CatchParameterNameCheck extends AbstractNameCheck {
66
67 /**
68 * Creates a new {@code CatchParameterNameCheck} instance.
69 */
70 public CatchParameterNameCheck() {
71 super("^(e|t|ex|[a-z][a-z][a-zA-Z]+|_)$");
72 }
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.PARAMETER_DEF};
87 }
88
89 @Override
90 protected boolean mustCheckName(DetailAST ast) {
91 return ast.getParent().getType() == TokenTypes.LITERAL_CATCH;
92 }
93
94 }