Source code

001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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;
021
022import java.io.OutputStream;
023import java.io.OutputStreamWriter;
024import java.io.PrintWriter;
025import java.io.StringWriter;
026import java.nio.charset.StandardCharsets;
027import java.util.ArrayList;
028import java.util.Collections;
029import java.util.List;
030import java.util.Map;
031import java.util.concurrent.ConcurrentHashMap;
032
033import com.puppycrawl.tools.checkstyle.api.AuditEvent;
034import com.puppycrawl.tools.checkstyle.api.AuditListener;
035import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
036import com.puppycrawl.tools.checkstyle.api.SeverityLevel;
037import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
038
039/**
040 * Simple XML logger.
041 * It outputs everything in UTF-8 (default XML encoding is UTF-8) in case
042 * we want to localize error messages or simply that file names are
043 * localized and takes care about escaping as well.
044
045 */
046// -@cs[AbbreviationAsWordInName] We can not change it as,
047// check's name is part of API (used in configurations).
048public class XMLLogger
049    extends AutomaticBean
050    implements AuditListener {
051
052    /** Decimal radix. */
053    private static final int BASE_10 = 10;
054
055    /** Hex radix. */
056    private static final int BASE_16 = 16;
057
058    /** Some known entities to detect. */
059    private static final String[] ENTITIES = {"gt", "amp", "lt", "apos",
060                                              "quot", };
061
062    /** Close output stream in auditFinished. */
063    private final boolean closeStream;
064
065    /** The writer lock object. */
066    private final Object writerLock = new Object();
067
068    /** Holds all messages for the given file. */
069    private final Map<String, FileMessages> fileMessages =
070            new ConcurrentHashMap<>();
071
072    /**
073     * Helper writer that allows easy encoding and printing.
074     */
075    private final PrintWriter writer;
076
077    /**
078     * Creates a new {@code XMLLogger} instance.
079     * Sets the output to a defined stream.
080     * @param outputStream the stream to write logs to.
081     * @param outputStreamOptions if {@code CLOSE} stream should be closed in auditFinished()
082     */
083    public XMLLogger(OutputStream outputStream, OutputStreamOptions outputStreamOptions) {
084        writer = new PrintWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
085        if (outputStreamOptions == null) {
086            throw new IllegalArgumentException("Parameter outputStreamOptions can not be null");
087        }
088        closeStream = outputStreamOptions == OutputStreamOptions.CLOSE;
089    }
090
091    @Override
092    protected void finishLocalSetup() {
093        // No code by default
094    }
095
096    @Override
097    public void auditStarted(AuditEvent event) {
098        writer.println("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
099
100        final String version = XMLLogger.class.getPackage().getImplementationVersion();
101
102        writer.println("<checkstyle version=\"" + version + "\">");
103    }
104
105    @Override
106    public void auditFinished(AuditEvent event) {
107        writer.println("</checkstyle>");
108        if (closeStream) {
109            writer.close();
110        }
111        else {
112            writer.flush();
113        }
114    }
115
116    @Override
117    public void fileStarted(AuditEvent event) {
118        fileMessages.put(event.getFileName(), new FileMessages());
119    }
120
121    @Override
122    public void fileFinished(AuditEvent event) {
123        final String fileName = event.getFileName();
124        final FileMessages messages = fileMessages.get(fileName);
125
126        synchronized (writerLock) {
127            writeFileMessages(fileName, messages);
128        }
129
130        fileMessages.remove(fileName);
131    }
132
133    /**
134     * Prints the file section with all file errors and exceptions.
135     * @param fileName The file name, as should be printed in the opening file tag.
136     * @param messages The file messages.
137     */
138    private void writeFileMessages(String fileName, FileMessages messages) {
139        writeFileOpeningTag(fileName);
140        if (messages != null) {
141            for (AuditEvent errorEvent : messages.getErrors()) {
142                writeFileError(errorEvent);
143            }
144            for (Throwable exception : messages.getExceptions()) {
145                writeException(exception);
146            }
147        }
148        writeFileClosingTag();
149    }
150
151    /**
152     * Prints the "file" opening tag with the given filename.
153     * @param fileName The filename to output.
154     */
155    private void writeFileOpeningTag(String fileName) {
156        writer.println("<file name=\"" + encode(fileName) + "\">");
157    }
158
159    /**
160     * Prints the "file" closing tag.
161     */
162    private void writeFileClosingTag() {
163        writer.println("</file>");
164    }
165
166    @Override
167    public void addError(AuditEvent event) {
168        if (event.getSeverityLevel() != SeverityLevel.IGNORE) {
169            final String fileName = event.getFileName();
170            if (fileName == null || !fileMessages.containsKey(fileName)) {
171                synchronized (writerLock) {
172                    writeFileError(event);
173                }
174            }
175            else {
176                final FileMessages messages = fileMessages.get(fileName);
177                messages.addError(event);
178            }
179        }
180    }
181
182    /**
183     * Outputs the given event to the writer.
184     * @param event An event to print.
185     */
186    private void writeFileError(AuditEvent event) {
187        writer.print("<error" + " line=\"" + event.getLine() + "\"");
188        if (event.getColumn() > 0) {
189            writer.print(" column=\"" + event.getColumn() + "\"");
190        }
191        writer.print(" severity=\""
192                + event.getSeverityLevel().getName()
193                + "\"");
194        writer.print(" message=\""
195                + encode(event.getMessage())
196                + "\"");
197        writer.print(" source=\"");
198        if (event.getModuleId() == null) {
199            writer.print(encode(event.getSourceName()));
200        }
201        else {
202            writer.print(encode(event.getModuleId()));
203        }
204        writer.println("\"/>");
205    }
206
207    @Override
208    public void addException(AuditEvent event, Throwable throwable) {
209        final String fileName = event.getFileName();
210        if (fileName == null || !fileMessages.containsKey(fileName)) {
211            synchronized (writerLock) {
212                writeException(throwable);
213            }
214        }
215        else {
216            final FileMessages messages = fileMessages.get(fileName);
217            messages.addException(throwable);
218        }
219    }
220
221    /**
222     * Writes the exception event to the print writer.
223     * @param throwable The
224     */
225    private void writeException(Throwable throwable) {
226        writer.println("<exception>");
227        writer.println("<![CDATA[");
228
229        final StringWriter stringWriter = new StringWriter();
230        final PrintWriter printer = new PrintWriter(stringWriter);
231        throwable.printStackTrace(printer);
232        writer.println(encode(stringWriter.toString()));
233
234        writer.println("]]>");
235        writer.println("</exception>");
236    }
237
238    /**
239     * Escape &lt;, &gt; &amp; &#39; and &quot; as their entities.
240     * @param value the value to escape.
241     * @return the escaped value if necessary.
242     */
243    public static String encode(String value) {
244        final StringBuilder sb = new StringBuilder(256);
245        for (int i = 0; i < value.length(); i++) {
246            final char chr = value.charAt(i);
247            switch (chr) {
248                case '<':
249                    sb.append("&lt;");
250                    break;
251                case '>':
252                    sb.append("&gt;");
253                    break;
254                case '\'':
255                    sb.append("&apos;");
256                    break;
257                case '\"':
258                    sb.append("&quot;");
259                    break;
260                case '&':
261                    sb.append("&amp;");
262                    break;
263                case '\r':
264                    break;
265                case '\n':
266                    sb.append("&#10;");
267                    break;
268                default:
269                    if (Character.isISOControl(chr)) {
270                        // true escape characters need '&' before but it also requires XML 1.1
271                        // until https://github.com/checkstyle/checkstyle/issues/5168
272                        sb.append("#x");
273                        sb.append(Integer.toHexString(chr));
274                        sb.append(';');
275                    }
276                    else {
277                        sb.append(chr);
278                    }
279                    break;
280            }
281        }
282        return sb.toString();
283    }
284
285    /**
286     * Finds whether the given argument is character or entity reference.
287     * @param ent the possible entity to look for.
288     * @return whether the given argument a character or entity reference
289     */
290    public static boolean isReference(String ent) {
291        boolean reference = false;
292
293        if (ent.charAt(0) == '&' && CommonUtil.endsWithChar(ent, ';')) {
294            if (ent.charAt(1) == '#') {
295                // prefix is "&#"
296                int prefixLength = 2;
297
298                int radix = BASE_10;
299                if (ent.charAt(2) == 'x') {
300                    prefixLength++;
301                    radix = BASE_16;
302                }
303                try {
304                    Integer.parseInt(
305                        ent.substring(prefixLength, ent.length() - 1), radix);
306                    reference = true;
307                }
308                catch (final NumberFormatException ignored) {
309                    reference = false;
310                }
311            }
312            else {
313                final String name = ent.substring(1, ent.length() - 1);
314                for (String element : ENTITIES) {
315                    if (name.equals(element)) {
316                        reference = true;
317                        break;
318                    }
319                }
320            }
321        }
322
323        return reference;
324    }
325
326    /**
327     * The registered file messages.
328     */
329    private static class FileMessages {
330
331        /** The file error events. */
332        private final List<AuditEvent> errors = Collections.synchronizedList(new ArrayList<>());
333
334        /** The file exceptions. */
335        private final List<Throwable> exceptions = Collections.synchronizedList(new ArrayList<>());
336
337        /**
338         * Returns the file error events.
339         * @return the file error events.
340         */
341        public List<AuditEvent> getErrors() {
342            return Collections.unmodifiableList(errors);
343        }
344
345        /**
346         * Adds the given error event to the messages.
347         * @param event the error event.
348         */
349        public void addError(AuditEvent event) {
350            errors.add(event);
351        }
352
353        /**
354         * Returns the file exceptions.
355         * @return the file exceptions.
356         */
357        public List<Throwable> getExceptions() {
358            return Collections.unmodifiableList(exceptions);
359        }
360
361        /**
362         * Adds the given exception to the messages.
363         * @param throwable the file exception
364         */
365        public void addException(Throwable throwable) {
366            exceptions.add(throwable);
367        }
368
369    }
370
371}