001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2019 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.annotation;
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;
026import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
027
028/**
029 * The check does verifying that annotations are located on the same line with their targets.
030 * Verifying with this check is not good practice, but it is using by some style guides.
031 */
032@StatelessCheck
033public class AnnotationOnSameLineCheck extends AbstractCheck {
034
035    /** A key is pointing to the warning message text in "messages.properties" file. */
036    public static final String MSG_KEY_ANNOTATION_ON_SAME_LINE = "annotation.same.line";
037
038    @Override
039    public int[] getDefaultTokens() {
040        return new int[] {
041            TokenTypes.CLASS_DEF,
042            TokenTypes.INTERFACE_DEF,
043            TokenTypes.ENUM_DEF,
044            TokenTypes.METHOD_DEF,
045            TokenTypes.CTOR_DEF,
046            TokenTypes.VARIABLE_DEF,
047        };
048    }
049
050    @Override
051    public int[] getAcceptableTokens() {
052        return new int[] {
053            TokenTypes.CLASS_DEF,
054            TokenTypes.INTERFACE_DEF,
055            TokenTypes.ENUM_DEF,
056            TokenTypes.METHOD_DEF,
057            TokenTypes.CTOR_DEF,
058            TokenTypes.VARIABLE_DEF,
059            TokenTypes.PARAMETER_DEF,
060            TokenTypes.ANNOTATION_DEF,
061            TokenTypes.TYPECAST,
062            TokenTypes.LITERAL_THROWS,
063            TokenTypes.IMPLEMENTS_CLAUSE,
064            TokenTypes.TYPE_ARGUMENT,
065            TokenTypes.LITERAL_NEW,
066            TokenTypes.DOT,
067            TokenTypes.ANNOTATION_FIELD_DEF,
068        };
069    }
070
071    @Override
072    public int[] getRequiredTokens() {
073        return CommonUtil.EMPTY_INT_ARRAY;
074    }
075
076    @Override
077    public void visitToken(DetailAST ast) {
078        DetailAST nodeWithAnnotations = ast;
079        if (ast.getType() == TokenTypes.TYPECAST) {
080            nodeWithAnnotations = ast.findFirstToken(TokenTypes.TYPE);
081        }
082        DetailAST modifiersNode = nodeWithAnnotations.findFirstToken(TokenTypes.MODIFIERS);
083        if (modifiersNode == null) {
084            modifiersNode = nodeWithAnnotations.findFirstToken(TokenTypes.ANNOTATIONS);
085        }
086        if (modifiersNode != null) {
087            for (DetailAST annotationNode = modifiersNode.getFirstChild();
088                    annotationNode != null;
089                    annotationNode = annotationNode.getNextSibling()) {
090                if (annotationNode.getType() == TokenTypes.ANNOTATION
091                        && annotationNode.getLineNo() != getNextNode(annotationNode).getLineNo()) {
092                    log(annotationNode.getLineNo(), MSG_KEY_ANNOTATION_ON_SAME_LINE,
093                          getAnnotationName(annotationNode));
094                }
095            }
096        }
097    }
098
099    /**
100     * Finds next node of ast tree.
101     * @param node current node
102     * @return node that is next to given
103     */
104    private static DetailAST getNextNode(DetailAST node) {
105        DetailAST nextNode = node.getNextSibling();
106        if (nextNode == null) {
107            nextNode = node.getParent().getNextSibling();
108        }
109        return nextNode;
110    }
111
112    /**
113     * Returns the name of the given annotation.
114     * @param annotation annotation node.
115     * @return annotation name.
116     */
117    private static String getAnnotationName(DetailAST annotation) {
118        DetailAST identNode = annotation.findFirstToken(TokenTypes.IDENT);
119        if (identNode == null) {
120            identNode = annotation.findFirstToken(TokenTypes.DOT).getLastChild();
121        }
122        return identNode.getText();
123    }
124
125}