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.coding;
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 * Restricts nested try-catch-finally blocks to a specified depth (default = 1).
028 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
029 */
030public final class NestedTryDepthCheck extends AbstractCheck {
031
032    /**
033     * A key is pointing to the warning message text in "messages.properties"
034     * file.
035     */
036    public static final String MSG_KEY = "nested.try.depth";
037
038    /** Maximum allowed nesting depth. */
039    private int max = 1;
040    /** Current nesting depth. */
041    private int depth;
042
043    /**
044     * Setter for maximum allowed nesting depth.
045     * @param max maximum allowed nesting depth.
046     */
047    public void setMax(int max) {
048        this.max = max;
049    }
050
051    @Override
052    public int[] getDefaultTokens() {
053        return getAcceptableTokens();
054    }
055
056    @Override
057    public int[] getAcceptableTokens() {
058        return new int[] {TokenTypes.LITERAL_TRY};
059    }
060
061    @Override
062    public int[] getRequiredTokens() {
063        return getAcceptableTokens();
064    }
065
066    @Override
067    public void beginTree(DetailAST rootAST) {
068        depth = 0;
069    }
070
071    @Override
072    public void visitToken(DetailAST literalTry) {
073        if (depth > max) {
074            log(literalTry, MSG_KEY, depth, max);
075        }
076        ++depth;
077    }
078
079    @Override
080    public void leaveToken(DetailAST literalTry) {
081        --depth;
082    }
083
084}