001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 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.sizes;
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;
026
027/**
028 * <div>
029 * Checks for long anonymous inner classes.
030 * </div>
031 *
032 * <p>
033 * Rationale: If an anonymous inner class becomes very long
034 * it is hard to understand and to see the flow of the method
035 * where the class is defined. Therefore, long anonymous inner
036 * classes should usually be refactored into a named inner class.
037 * See also Bloch, Effective Java, p. 93.
038 * </p>
039 * <ul>
040 * <li>
041 * Property {@code max} - Specify the maximum number of lines allowed.
042 * Type is {@code int}.
043 * Default value is {@code 20}.
044 * </li>
045 * </ul>
046 *
047 * <p>
048 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
049 * </p>
050 *
051 * <p>
052 * Violation Message Keys:
053 * </p>
054 * <ul>
055 * <li>
056 * {@code maxLen.anonInner}
057 * </li>
058 * </ul>
059 *
060 * @since 3.2
061 */
062@StatelessCheck
063public class AnonInnerLengthCheck extends AbstractCheck {
064
065    /**
066     * A key is pointing to the warning message text in "messages.properties"
067     * file.
068     */
069    public static final String MSG_KEY = "maxLen.anonInner";
070
071    /** Default maximum number of lines. */
072    private static final int DEFAULT_MAX = 20;
073
074    /** Specify the maximum number of lines allowed. */
075    private int max = DEFAULT_MAX;
076
077    @Override
078    public int[] getDefaultTokens() {
079        return getRequiredTokens();
080    }
081
082    @Override
083    public int[] getAcceptableTokens() {
084        return getRequiredTokens();
085    }
086
087    @Override
088    public int[] getRequiredTokens() {
089        return new int[] {TokenTypes.LITERAL_NEW};
090    }
091
092    @Override
093    public void visitToken(DetailAST ast) {
094        final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
095        if (openingBrace != null) {
096            final DetailAST closingBrace =
097                openingBrace.findFirstToken(TokenTypes.RCURLY);
098            final int length =
099                closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
100            if (length > max) {
101                log(ast, MSG_KEY, length, max);
102            }
103        }
104    }
105
106    /**
107     * Setter to specify the maximum number of lines allowed.
108     *
109     * @param length the maximum length of an anonymous inner class.
110     * @since 3.2
111     */
112    public void setMax(int length) {
113        max = length;
114    }
115
116}