1 /*
2 * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26
27 package java.util.logging;
28
29 import java.nio.charset.Charset;
30 import java.time.Instant;
31 import java.time.format.DateTimeFormatter;
32 import java.util.*;
33
34 /**
35 * Format a LogRecord into a standard XML format.
36 * <p>
37 * The DTD specification is provided as Appendix A to the
38 * Java Logging APIs specification.
39 * <p>
40 * The XMLFormatter can be used with arbitrary character encodings,
41 * but it is recommended that it normally be used with UTF-8. The
42 * character encoding can be set on the output Handler.
43 *
44 * @implSpec Since JDK 9, instances of {@linkplain LogRecord} contain
45 * an {@link LogRecord#getInstant() Instant} which can have nanoseconds below
46 * the millisecond resolution.
47 * The DTD specification has been updated to allow for an optional
48 * {@code <nanos>} element. By default, the XMLFormatter will compute the
49 * nanosecond adjustment below the millisecond resolution (using
50 * {@code LogRecord.getInstant().getNano() % 1000_000}) - and if this is not 0,
51 * this adjustment value will be printed in the new {@code <nanos>} element.
52 * The event instant can then be reconstructed using
53 * {@code Instant.ofEpochSecond(millis/1000L, (millis % 1000L) * 1000_000L + nanos)}
54 * where {@code millis} and {@code nanos} represent the numbers serialized in
55 * the {@code <millis>} and {@code <nanos>} elements, respectively.
56 * <br>
57 * The {@code <date>} element will now contain the whole instant as formatted
58 * by the {@link DateTimeFormatter#ISO_INSTANT DateTimeFormatter.ISO_INSTANT}
59 * formatter.
60 * <p>
61 * For compatibility with old parsers, XMLFormatters can
62 * be configured to revert to the old format by specifying a
63 * {@code <xml-formatter-fully-qualified-class-name>.useInstant = false}
64 * {@linkplain LogManager#getProperty(java.lang.String) property} in the
65 * logging configuration. When {@code useInstant} is {@code false}, the old
66 * formatting will be preserved. When {@code useInstant} is {@code true}
67 * (the default), the {@code <nanos>} element will be printed and the
68 * {@code <date>} element will contain the {@linkplain
69 * DateTimeFormatter#ISO_INSTANT formatted} instant.
70 * <p>
71 * For instance, in order to configure plain instances of XMLFormatter to omit
72 * the new {@code <nano>} element,
73 * {@code java.util.logging.XMLFormatter.useInstant = false} can be specified
74 * in the logging configuration.
75 *
76 * @since 1.4
77 */
78
79 public class XMLFormatter extends Formatter {
80 private final LogManager manager = LogManager.getLogManager();
81 private final boolean useInstant;
82
83 /**
84 * Creates a new instance of XMLFormatter.
85 *
86 * @implSpec
87 * Since JDK 9, the XMLFormatter will print out the record {@linkplain
88 * LogRecord#getInstant() event time} as an Instant. This instant
89 * has the best resolution available on the system. The {@code <date>}
90 * element will contain the instant as formatted by the {@link
91 * DateTimeFormatter#ISO_INSTANT}.
92 * In addition, an optional {@code <nanos>} element containing a
93 * nanosecond adjustment will be printed if the instant contains some
94 * nanoseconds below the millisecond resolution.
95 * <p>
96 * This new behavior can be turned off, and the old formatting restored,
97 * by specifying a property in the {@linkplain
98 * LogManager#getProperty(java.lang.String) logging configuration}.
99 * If {@code LogManager.getLogManager().getProperty(
100 * this.getClass().getName()+".useInstant")} is {@code "false"} or
101 * {@code "0"}, the old formatting will be restored.
102 */
103 public XMLFormatter() {
104 useInstant = (manager == null)
105 || manager.getBooleanProperty(
106 this.getClass().getName()+".useInstant", true);
107 }
108
109 // Append a two digit number.
110 private void a2(StringBuilder sb, int x) {
111 if (x < 10) {
112 sb.append('0');
113 }
114 sb.append(x);
115 }
116
117 // Append the time and date in ISO 8601 format
118 private void appendISO8601(StringBuilder sb, long millis) {
119 GregorianCalendar cal = new GregorianCalendar();
120 cal.setTimeInMillis(millis);
121 sb.append(cal.get(Calendar.YEAR));
122 sb.append('-');
123 a2(sb, cal.get(Calendar.MONTH) + 1);
124 sb.append('-');
125 a2(sb, cal.get(Calendar.DAY_OF_MONTH));
126 sb.append('T');
127 a2(sb, cal.get(Calendar.HOUR_OF_DAY));
128 sb.append(':');
129 a2(sb, cal.get(Calendar.MINUTE));
130 sb.append(':');
131 a2(sb, cal.get(Calendar.SECOND));
132 }
133
134 // Append to the given StringBuilder an escaped version of the
135 // given text string where XML special characters have been escaped.
136 // For a null string we append "<null>"
137 private void escape(StringBuilder sb, String text) {
138 if (text == null) {
139 text = "<null>";
140 }
141 for (int i = 0; i < text.length(); i++) {
142 char ch = text.charAt(i);
143 if (ch == '<') {
144 sb.append("<");
145 } else if (ch == '>') {
146 sb.append(">");
147 } else if (ch == '&') {
148 sb.append("&");
149 } else {
150 sb.append(ch);
151 }
152 }
153 }
154
155 /**
156 * Format the given message to XML.
157 * <p>
158 * This method can be overridden in a subclass.
159 * It is recommended to use the {@link Formatter#formatMessage}
160 * convenience method to localize and format the message field.
161 *
162 * @param record the log record to be formatted.
163 * @return a formatted log record
164 */
165 @Override
166 public String format(LogRecord record) {
167 StringBuilder sb = new StringBuilder(500);
168 sb.append("<record>\n");
169
170 final Instant instant = record.getInstant();
171
172 sb.append(" <date>");
173 if (useInstant) {
174 // If useInstant is true - we will print the instant in the
175 // date field, using the ISO_INSTANT formatter.
176 DateTimeFormatter.ISO_INSTANT.formatTo(instant, sb);
177 } else {
178 // If useInstant is false - we will keep the 'old' formating
179 appendISO8601(sb, instant.toEpochMilli());
180 }
181 sb.append("</date>\n");
182
183 sb.append(" <millis>");
184 sb.append(instant.toEpochMilli());
185 sb.append("</millis>\n");
186
187 final int nanoAdjustment = instant.getNano() % 1000_000;
188 if (useInstant && nanoAdjustment != 0) {
189 sb.append(" <nanos>");
190 sb.append(nanoAdjustment);
191 sb.append("</nanos>\n");
192 }
193
194 sb.append(" <sequence>");
195 sb.append(record.getSequenceNumber());
196 sb.append("</sequence>\n");
197
198 String name = record.getLoggerName();
199 if (name != null) {
200 sb.append(" <logger>");
201 escape(sb, name);
202 sb.append("</logger>\n");
203 }
204
205 sb.append(" <level>");
206 escape(sb, record.getLevel().toString());
207 sb.append("</level>\n");
208
209 if (record.getSourceClassName() != null) {
210 sb.append(" <class>");
211 escape(sb, record.getSourceClassName());
212 sb.append("</class>\n");
213 }
214
215 if (record.getSourceMethodName() != null) {
216 sb.append(" <method>");
217 escape(sb, record.getSourceMethodName());
218 sb.append("</method>\n");
219 }
220
221 sb.append(" <thread>");
222 sb.append(record.getThreadID());
223 sb.append("</thread>\n");
224
225 if (record.getMessage() != null) {
226 // Format the message string and its accompanying parameters.
227 String message = formatMessage(record);
228 sb.append(" <message>");
229 escape(sb, message);
230 sb.append("</message>");
231 sb.append("\n");
232 }
233
234 // If the message is being localized, output the key, resource
235 // bundle name, and params.
236 ResourceBundle bundle = record.getResourceBundle();
237 try {
238 if (bundle != null && bundle.getString(record.getMessage()) != null) {
239 sb.append(" <key>");
240 escape(sb, record.getMessage());
241 sb.append("</key>\n");
242 sb.append(" <catalog>");
243 escape(sb, record.getResourceBundleName());
244 sb.append("</catalog>\n");
245 }
246 } catch (Exception ex) {
247 // The message is not in the catalog. Drop through.
248 }
249
250 Object parameters[] = record.getParameters();
251 // Check to see if the parameter was not a messagetext format
252 // or was not null or empty
253 if (parameters != null && parameters.length != 0
254 && record.getMessage().indexOf('{') == -1 ) {
255 for (Object parameter : parameters) {
256 sb.append(" <param>");
257 try {
258 escape(sb, parameter.toString());
259 } catch (Exception ex) {
260 sb.append("???");
261 }
262 sb.append("</param>\n");
263 }
264 }
265
266 if (record.getThrown() != null) {
267 // Report on the state of the throwable.
268 Throwable th = record.getThrown();
269 sb.append(" <exception>\n");
270 sb.append(" <message>");
271 escape(sb, th.toString());
272 sb.append("</message>\n");
273 StackTraceElement trace[] = th.getStackTrace();
274 for (StackTraceElement frame : trace) {
275 sb.append(" <frame>\n");
276 sb.append(" <class>");
277 escape(sb, frame.getClassName());
278 sb.append("</class>\n");
279 sb.append(" <method>");
280 escape(sb, frame.getMethodName());
281 sb.append("</method>\n");
282 // Check for a line number.
283 if (frame.getLineNumber() >= 0) {
284 sb.append(" <line>");
285 sb.append(frame.getLineNumber());
286 sb.append("</line>\n");
287 }
288 sb.append(" </frame>\n");
289 }
290 sb.append(" </exception>\n");
291 }
292
293 sb.append("</record>\n");
294 return sb.toString();
295 }
296
297 /**
298 * Return the header string for a set of XML formatted records.
299 *
300 * @param h The target handler (can be null)
301 * @return a valid XML string
302 */
303 @Override
304 public String getHead(Handler h) {
305 StringBuilder sb = new StringBuilder();
306 String encoding;
307 sb.append("<?xml version=\"1.0\"");
308
309 if (h != null) {
310 encoding = h.getEncoding();
311 } else {
312 encoding = null;
313 }
314
315 if (encoding == null) {
316 // Figure out the default encoding.
317 encoding = java.nio.charset.Charset.defaultCharset().name();
318 }
319 // Try to map the encoding name to a canonical name.
320 try {
321 Charset cs = Charset.forName(encoding);
322 encoding = cs.name();
323 } catch (Exception ex) {
324 // We hit problems finding a canonical name.
325 // Just use the raw encoding name.
326 }
327
328 sb.append(" encoding=\"");
329 sb.append(encoding);
330 sb.append("\"");
331 sb.append(" standalone=\"no\"?>\n");
332
333 sb.append("<!DOCTYPE log SYSTEM \"logger.dtd\">\n");
334 sb.append("<log>\n");
335 return sb.toString();
336 }
337
338 /**
339 * Return the tail string for a set of XML formatted records.
340 *
341 * @param h The target handler (can be null)
342 * @return a valid XML string
343 */
344 @Override
345 public String getTail(Handler h) {
346 return "</log>\n";
347 }
348 }