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.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 * Restricts nested try-catch-finally blocks to a specified depth (default = 1).
029 * @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris</a>
030 */
031@FileStatefulCheck
032public final class NestedTryDepthCheck extends AbstractCheck {
033
034    /**
035     * A key is pointing to the warning message text in "messages.properties"
036     * file.
037     */
038    public static final String MSG_KEY = "nested.try.depth";
039
040    /** Maximum allowed nesting depth. */
041    private int max = 1;
042    /** Current nesting depth. */
043    private int depth;
044
045    /**
046     * Setter for maximum allowed nesting depth.
047     * @param max maximum allowed nesting depth.
048     */
049    public void setMax(int max) {
050        this.max = max;
051    }
052
053    @Override
054    public int[] getDefaultTokens() {
055        return getRequiredTokens();
056    }
057
058    @Override
059    public int[] getAcceptableTokens() {
060        return getRequiredTokens();
061    }
062
063    @Override
064    public int[] getRequiredTokens() {
065        return new int[] {TokenTypes.LITERAL_TRY};
066    }
067
068    @Override
069    public void beginTree(DetailAST rootAST) {
070        depth = 0;
071    }
072
073    @Override
074    public void visitToken(DetailAST literalTry) {
075        if (depth > max) {
076            log(literalTry, MSG_KEY, depth, max);
077        }
078        ++depth;
079    }
080
081    @Override
082    public void leaveToken(DetailAST literalTry) {
083        --depth;
084    }
085
086}