001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 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 *
040 * @since 3.2
041 */
042@StatelessCheck
043public class AnonInnerLengthCheck extends AbstractCheck {
044
045    /**
046     * A key is pointing to the warning message text in "messages.properties" file.
047     */
048    public static final String MSG_KEY = "maxLen.anonInner";
049
050    /** Default maximum number of lines. */
051    private static final int DEFAULT_MAX = 20;
052
053    /** Specify the maximum number of lines allowed. */
054    private int max = DEFAULT_MAX;
055
056    /**
057     * Creates a new {@code AnonInnerLengthCheck} instance.
058     */
059    public AnonInnerLengthCheck() {
060        // no code by default
061    }
062
063    @Override
064    public int[] getDefaultTokens() {
065        return getRequiredTokens();
066    }
067
068    @Override
069    public int[] getAcceptableTokens() {
070        return getRequiredTokens();
071    }
072
073    @Override
074    public int[] getRequiredTokens() {
075        return new int[] {TokenTypes.LITERAL_NEW};
076    }
077
078    @Override
079    public void visitToken(DetailAST ast) {
080        final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
081        if (openingBrace != null) {
082            final DetailAST closingBrace =
083                openingBrace.findFirstToken(TokenTypes.RCURLY);
084            final int length =
085                closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
086            if (length > max) {
087                log(ast, MSG_KEY, length, max);
088            }
089        }
090    }
091
092    /**
093     * Setter to specify the maximum number of lines allowed.
094     *
095     * @param length the maximum length of an anonymous inner class.
096     * @since 3.2
097     */
098    public void setMax(int length) {
099        max = length;
100    }
101
102}