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.coding;
021
022import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
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 * Restricts nested try-catch-finally blocks to a specified depth.
030 * </p>
031 * <ul>
032 * <li>
033 * Property {@code max} - Specify maximum allowed nesting depth.
034 * Type is {@code int}.
035 * Default value is {@code 1}.
036 * </li>
037 * </ul>
038 * <p>
039 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
040 * </p>
041 * <p>
042 * Violation Message Keys:
043 * </p>
044 * <ul>
045 * <li>
046 * {@code nested.try.depth}
047 * </li>
048 * </ul>
049 *
050 * @since 3.2
051 */
052@FileStatefulCheck
053public final class NestedTryDepthCheck extends AbstractCheck {
054
055    /**
056     * A key is pointing to the warning message text in "messages.properties"
057     * file.
058     */
059    public static final String MSG_KEY = "nested.try.depth";
060
061    /** Specify maximum allowed nesting depth. */
062    private int max = 1;
063    /** Current nesting depth. */
064    private int depth;
065
066    /**
067     * Setter to specify maximum allowed nesting depth.
068     *
069     * @param max maximum allowed nesting depth.
070     * @since 3.2
071     */
072    public void setMax(int max) {
073        this.max = max;
074    }
075
076    @Override
077    public int[] getDefaultTokens() {
078        return getRequiredTokens();
079    }
080
081    @Override
082    public int[] getAcceptableTokens() {
083        return getRequiredTokens();
084    }
085
086    @Override
087    public int[] getRequiredTokens() {
088        return new int[] {TokenTypes.LITERAL_TRY};
089    }
090
091    @Override
092    public void visitToken(DetailAST literalTry) {
093        if (depth > max) {
094            log(literalTry, MSG_KEY, depth, max);
095        }
096        ++depth;
097    }
098
099    @Override
100    public void leaveToken(DetailAST literalTry) {
101        --depth;
102    }
103
104}