001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2018 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 * <p>
029 * Checks for long anonymous inner classes.
030 * </p>
031 * <p>
032 * Rationale: If an anonymous inner class becomes very long
033 * it is hard to understand and to see the flow of the method
034 * where the class is defined. Therefore long anonymous inner
035 * classes should usually be refactored into a named inner class.
036 * See also Bloch, Effective Java, p. 93.
037 * </p>
038 * <p>
039 * The default maximum anonymous inner class length is 20 lines.
040 * To change the maximum number of lines, set property max.
041 * </p>
042 * <p>
043 * An example of how to configure the check is:
044 * </p>
045 * <pre>
046 * &lt;module name="AnonInnerLength"/&gt;
047 * </pre>
048 * <p>
049 * An example of how to configure the check so that it accepts anonymous
050 * inner classes with up to 60 lines is:
051 * </p>
052 * <pre>
053 * &lt;module name="AnonInnerLength"&gt;
054 *    &lt;property name="max" value="60"/&gt;
055 * &lt;/module&gt;
056 * </pre>
057 *
058 */
059@StatelessCheck
060public class AnonInnerLengthCheck extends AbstractCheck {
061
062    /**
063     * A key is pointing to the warning message text in "messages.properties"
064     * file.
065     */
066    public static final String MSG_KEY = "maxLen.anonInner";
067
068    /** Default maximum number of lines. */
069    private static final int DEFAULT_MAX = 20;
070
071    /** Maximum number of lines. */
072    private int max = DEFAULT_MAX;
073
074    @Override
075    public int[] getDefaultTokens() {
076        return getRequiredTokens();
077    }
078
079    @Override
080    public int[] getAcceptableTokens() {
081        return getRequiredTokens();
082    }
083
084    @Override
085    public int[] getRequiredTokens() {
086        return new int[] {TokenTypes.LITERAL_NEW};
087    }
088
089    @Override
090    public void visitToken(DetailAST ast) {
091        final DetailAST openingBrace = ast.findFirstToken(TokenTypes.OBJBLOCK);
092        if (openingBrace != null) {
093            final DetailAST closingBrace =
094                openingBrace.findFirstToken(TokenTypes.RCURLY);
095            final int length =
096                closingBrace.getLineNo() - openingBrace.getLineNo() + 1;
097            if (length > max) {
098                log(ast.getLineNo(), ast.getColumnNo(), MSG_KEY,
099                        length, max);
100            }
101        }
102    }
103
104    /**
105     * Sets maximum length of an anonymous inner class.
106     * @param length the maximum length of an anonymous inner class.
107     */
108    public void setMax(int length) {
109        max = length;
110    }
111
112}