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.coding;
021
022import java.util.Arrays;
023import java.util.Collections;
024import java.util.Set;
025import java.util.stream.Collectors;
026
027import com.puppycrawl.tools.checkstyle.StatelessCheck;
028import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
029import com.puppycrawl.tools.checkstyle.api.DetailAST;
030import com.puppycrawl.tools.checkstyle.api.FullIdent;
031import com.puppycrawl.tools.checkstyle.api.TokenTypes;
032import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
033import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
034
035/**
036 * <p>
037 * Throwing java.lang.Error or java.lang.RuntimeException
038 * is almost never acceptable.
039 * </p>
040 * Check has following properties:
041 * <p>
042 * <b>illegalClassNames</b> - throw class names to reject.
043 * </p>
044 * <p>
045 * <b>ignoredMethodNames</b> - names of methods to ignore.
046 * </p>
047 * <p>
048 * <b>ignoreOverriddenMethods</b> - ignore checking overridden methods (marked with Override
049 *  or java.lang.Override annotation) default value is <b>true</b>.
050 * </p>
051 *
052 */
053@StatelessCheck
054public final class IllegalThrowsCheck extends AbstractCheck {
055
056    /**
057     * A key is pointing to the warning message text in "messages.properties"
058     * file.
059     */
060    public static final String MSG_KEY = "illegal.throw";
061
062    /** Methods which should be ignored. */
063    private final Set<String> ignoredMethodNames =
064        Arrays.stream(new String[] {"finalize", }).collect(Collectors.toSet());
065
066    /** Illegal class names. */
067    private final Set<String> illegalClassNames = Arrays.stream(
068        new String[] {"Error", "RuntimeException", "Throwable", "java.lang.Error",
069                      "java.lang.RuntimeException", "java.lang.Throwable", })
070        .collect(Collectors.toSet());
071
072    /** Property for ignoring overridden methods. */
073    private boolean ignoreOverriddenMethods = true;
074
075    /**
076     * Set the list of illegal classes.
077     *
078     * @param classNames
079     *            array of illegal exception classes
080     */
081    public void setIllegalClassNames(final String... classNames) {
082        illegalClassNames.clear();
083        illegalClassNames.addAll(
084                CheckUtil.parseClassNames(classNames));
085    }
086
087    @Override
088    public int[] getDefaultTokens() {
089        return getRequiredTokens();
090    }
091
092    @Override
093    public int[] getRequiredTokens() {
094        return new int[] {TokenTypes.LITERAL_THROWS};
095    }
096
097    @Override
098    public int[] getAcceptableTokens() {
099        return getRequiredTokens();
100    }
101
102    @Override
103    public void visitToken(DetailAST detailAST) {
104        final DetailAST methodDef = detailAST.getParent();
105        // Check if the method with the given name should be ignored.
106        if (!isIgnorableMethod(methodDef)) {
107            DetailAST token = detailAST.getFirstChild();
108            while (token != null) {
109                if (token.getType() != TokenTypes.COMMA) {
110                    final FullIdent ident = FullIdent.createFullIdent(token);
111                    if (illegalClassNames.contains(ident.getText())) {
112                        log(token, MSG_KEY, ident.getText());
113                    }
114                }
115                token = token.getNextSibling();
116            }
117        }
118    }
119
120    /**
121     * Checks if current method is ignorable due to Check's properties.
122     * @param methodDef {@link TokenTypes#METHOD_DEF METHOD_DEF}
123     * @return true if method is ignorable.
124     */
125    private boolean isIgnorableMethod(DetailAST methodDef) {
126        return shouldIgnoreMethod(methodDef.findFirstToken(TokenTypes.IDENT).getText())
127            || ignoreOverriddenMethods
128               && (AnnotationUtil.containsAnnotation(methodDef, "Override")
129                  || AnnotationUtil.containsAnnotation(methodDef, "java.lang.Override"));
130    }
131
132    /**
133     * Check if the method is specified in the ignore method list.
134     * @param name the name to check
135     * @return whether the method with the passed name should be ignored
136     */
137    private boolean shouldIgnoreMethod(String name) {
138        return ignoredMethodNames.contains(name);
139    }
140
141    /**
142     * Set the list of ignore method names.
143     * @param methodNames array of ignored method names
144     */
145    public void setIgnoredMethodNames(String... methodNames) {
146        ignoredMethodNames.clear();
147        Collections.addAll(ignoredMethodNames, methodNames);
148    }
149
150    /**
151     * Sets <b>ignoreOverriddenMethods</b> property value.
152     * @param ignoreOverriddenMethods Check's property.
153     */
154    public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) {
155        this.ignoreOverriddenMethods = ignoreOverriddenMethods;
156    }
157
158}