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.imports;
021
022import java.net.URI;
023import java.util.Collections;
024import java.util.Set;
025import java.util.regex.Pattern;
026
027import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
028import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
029import com.puppycrawl.tools.checkstyle.api.CheckstyleException;
030import com.puppycrawl.tools.checkstyle.api.DetailAST;
031import com.puppycrawl.tools.checkstyle.api.ExternalResourceHolder;
032import com.puppycrawl.tools.checkstyle.api.FullIdent;
033import com.puppycrawl.tools.checkstyle.api.TokenTypes;
034
035/**
036 * Check that controls what packages can be imported in each package. Useful
037 * for ensuring that application layering is not violated. Ideas on how the
038 * check can be improved include support for:
039 * <ul>
040 * <li>
041 * Change the default policy that if a package being checked does not
042 * match any guards, then it is allowed. Currently defaults to disallowed.
043 * </li>
044 * </ul>
045 *
046 * @author Oliver Burn
047 */
048@FileStatefulCheck
049public class ImportControlCheck extends AbstractCheck implements ExternalResourceHolder {
050
051    /**
052     * A key is pointing to the warning message text in "messages.properties"
053     * file.
054     */
055    public static final String MSG_MISSING_FILE = "import.control.missing.file";
056
057    /**
058     * A key is pointing to the warning message text in "messages.properties"
059     * file.
060     */
061    public static final String MSG_UNKNOWN_PKG = "import.control.unknown.pkg";
062
063    /**
064     * A key is pointing to the warning message text in "messages.properties"
065     * file.
066     */
067    public static final String MSG_DISALLOWED = "import.control.disallowed";
068
069    /**
070     * A part of message for exception.
071     */
072    private static final String UNABLE_TO_LOAD = "Unable to load ";
073
074    /** Location of import control file. */
075    private String fileLocation;
076
077    /** The filepath pattern this check applies to. */
078    private Pattern path = Pattern.compile(".*");
079    /** Whether to process the current file. */
080    private boolean processCurrentFile;
081
082    /** The root package controller. */
083    private ImportControl root;
084    /** The package doing the import. */
085    private String packageName;
086
087    /**
088     * The package controller for the current file. Used for performance
089     * optimisation.
090     */
091    private ImportControl currentImportControl;
092
093    @Override
094    public int[] getDefaultTokens() {
095        return getRequiredTokens();
096    }
097
098    @Override
099    public int[] getAcceptableTokens() {
100        return getRequiredTokens();
101    }
102
103    @Override
104    public int[] getRequiredTokens() {
105        return new int[] {TokenTypes.PACKAGE_DEF, TokenTypes.IMPORT, TokenTypes.STATIC_IMPORT, };
106    }
107
108    @Override
109    public void beginTree(DetailAST rootAST) {
110        currentImportControl = null;
111        processCurrentFile = path.matcher(getFileContents().getFileName()).find();
112    }
113
114    @Override
115    public void visitToken(DetailAST ast) {
116        if (processCurrentFile) {
117            if (ast.getType() == TokenTypes.PACKAGE_DEF) {
118                if (root == null) {
119                    log(ast, MSG_MISSING_FILE);
120                }
121                else {
122                    packageName = getPackageText(ast);
123                    currentImportControl = root.locateFinest(packageName);
124                    if (currentImportControl == null) {
125                        log(ast, MSG_UNKNOWN_PKG);
126                    }
127                }
128            }
129            else if (currentImportControl != null) {
130                final String importText = getImportText(ast);
131                final AccessResult access =
132                        currentImportControl.checkAccess(packageName, importText);
133                if (access != AccessResult.ALLOWED) {
134                    log(ast, MSG_DISALLOWED, importText);
135                }
136            }
137        }
138    }
139
140    @Override
141    public Set<String> getExternalResourceLocations() {
142        return Collections.singleton(fileLocation);
143    }
144
145    /**
146     * Returns package text.
147     * @param ast PACKAGE_DEF ast node
148     * @return String that represents full package name
149     */
150    private static String getPackageText(DetailAST ast) {
151        final DetailAST nameAST = ast.getLastChild().getPreviousSibling();
152        return FullIdent.createFullIdent(nameAST).getText();
153    }
154
155    /**
156     * Returns import text.
157     * @param ast ast node that represents import
158     * @return String that represents importing class
159     */
160    private static String getImportText(DetailAST ast) {
161        final FullIdent imp;
162        if (ast.getType() == TokenTypes.IMPORT) {
163            imp = FullIdent.createFullIdentBelow(ast);
164        }
165        else {
166            // know it is a static import
167            imp = FullIdent.createFullIdent(ast
168                    .getFirstChild().getNextSibling());
169        }
170        return imp.getText();
171    }
172
173    /**
174     * Set the name for the file containing the import control
175     * configuration. It can also be a URL or resource in the classpath.
176     * It will cause the file to be loaded.
177     * @param uri the uri of the file to load.
178     * @throws IllegalArgumentException on error loading the file.
179     */
180    public void setFile(URI uri) {
181        // Handle empty param
182        if (uri != null) {
183            try {
184                root = ImportControlLoader.load(uri);
185                fileLocation = uri.toString();
186            }
187            catch (CheckstyleException ex) {
188                throw new IllegalArgumentException(UNABLE_TO_LOAD + uri, ex);
189            }
190        }
191    }
192
193    /**
194     * Set the file path pattern that this check applies to.
195     * @param pattern the file path regex this check should apply to.
196     */
197    public void setPath(Pattern pattern) {
198        path = pattern;
199    }
200}