001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2017 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.api.AbstractCheck;
023import com.puppycrawl.tools.checkstyle.api.DetailAST;
024import com.puppycrawl.tools.checkstyle.api.TokenTypes;
025
026/**
027 * <p>
028 * Checks for long anonymous inner classes.
029 * </p>
030 * <p>
031 * Rationale: If an anonymous inner class becomes very long
032 * it is hard to understand and to see the flow of the method
033 * where the class is defined. Therefore long anonymous inner
034 * classes should usually be refactored into a named inner class.
035 * See also Bloch, Effective Java, p. 93.
036 * </p>
037 * <p>
038 * The default maximum anonymous inner class length is 20 lines.
039 * To change the maximum number of lines, set property max.
040 * </p>
041 * <p>
042 * An example of how to configure the check is:
043 * </p>
044 * <pre>
045 * &lt;module name="AnonInnerLength"/&gt;
046 * </pre>
047 * <p>
048 * An example of how to configure the check so that it accepts anonymous
049 * inner classes with up to 60 lines is:
050 * </p>
051 * <pre>
052 * &lt;module name="AnonInnerLength"&gt;
053 *    &lt;property name="max" value="60"/&gt;
054 * &lt;/module&gt;
055 * </pre>
056 *
057 * @author Rob Worth
058 */
059public class AnonInnerLengthCheck extends AbstractCheck {
060
061    /**
062     * A key is pointing to the warning message text in "messages.properties"
063     * file.
064     */
065    public static final String MSG_KEY = "maxLen.anonInner";
066
067    /** Default maximum number of lines. */
068    private static final int DEFAULT_MAX = 20;
069
070    /** Maximum number of lines. */
071    private int max = DEFAULT_MAX;
072
073    @Override
074    public int[] getDefaultTokens() {
075        return getAcceptableTokens();
076    }
077
078    @Override
079    public int[] getAcceptableTokens() {
080        return new int[] {TokenTypes.LITERAL_NEW};
081    }
082
083    @Override
084    public int[] getRequiredTokens() {
085        return getAcceptableTokens();
086    }
087
088    @Override
089    public void visitToken(DetailAST ast) {
090        final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
091        if (openingBrace != null) {
092            final DetailAST closingBrace =
093                openingBrace.findFirstToken(TokenTypes.RCURLY);
094            final int length =
095                closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
096            if (length > max) {
097                log(ast.getLineNo(), ast.getColumnNo(), MSG_KEY,
098                        length, max);
099            }
100        }
101    }
102
103    /**
104     * Sets maximum length of an anonymous inner class.
105     * @param length the maximum length of an anonymous inner class.
106     */
107    public void setMax(int length) {
108        max = length;
109    }
110}