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18 package org.apache.logging.log4j.core.tools;
19
20 import java.io.PrintStream;
21 import java.util.ArrayList;
22 import java.util.Arrays;
23 import java.util.List;
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44 public final class Generate {
45
46 static final String PACKAGE_DECLARATION = "package %s;%n%n";
47
48 static enum Type {
49 CUSTOM {
50 String imports() {
51 return ""
52 + "import java.io.Serializable;%n"
53 + "import org.apache.logging.log4j.Level;%n"
54 + "import org.apache.logging.log4j.LogManager;%n" + "import org.apache.logging.log4j.Logger;%n"
55 + "import org.apache.logging.log4j.Marker;%n"
56 + "import org.apache.logging.log4j.message.Message;%n"
57 + "import org.apache.logging.log4j.message.MessageFactory;%n"
58 + "import org.apache.logging.log4j.spi.AbstractLogger;%n"
59 + "import org.apache.logging.log4j.spi.ExtendedLoggerWrapper;%n"
60 + "%n";
61 }
62
63 String declaration() {
64 return ""
65 + "/**%n"
66 + " * Custom Logger interface with convenience methods for%n"
67 + " * %s%n"
68 + " */%n"
69 + "public final class %s implements Serializable {%n"
70 + " private static final long serialVersionUID = " + System.nanoTime() + "L;%n"
71 + " private final ExtendedLoggerWrapper logger;%n"
72 + "%n"
73 ;
74 }
75
76 String constructor() {
77 return ""
78 + "%n"
79 + " private %s(final Logger logger) {%n"
80 + " this.logger = new ExtendedLoggerWrapper((AbstractLogger) logger, logger.getName(), logger.getMessageFactory());%n"
81 + " }%n"
82 ;
83 }
84
85 Class<?> generator() {
86 return CustomLogger.class;
87 }
88 },
89 EXTEND {
90 String imports() {
91 return ""
92 + "import org.apache.logging.log4j.Level;%n"
93 + "import org.apache.logging.log4j.LogManager;%n" + "import org.apache.logging.log4j.Logger;%n"
94 + "import org.apache.logging.log4j.Marker;%n"
95 + "import org.apache.logging.log4j.message.Message;%n"
96 + "import org.apache.logging.log4j.message.MessageFactory;%n"
97 + "import org.apache.logging.log4j.spi.AbstractLogger;%n"
98 + "import org.apache.logging.log4j.spi.ExtendedLoggerWrapper;%n"
99 + "%n";
100 }
101
102 String declaration() {
103 return ""
104 + "/**%n"
105 + " * Extended Logger interface with convenience methods for%n"
106 + " * %s%n"
107 + " */%n"
108 + "public final class %s extends ExtendedLoggerWrapper {%n"
109 + " private static final long serialVersionUID = " + System.nanoTime() + "L;%n"
110 + " private final ExtendedLoggerWrapper logger;%n"
111 + "%n"
112 ;
113 }
114
115 String constructor() {
116 return ""
117 + "%n"
118 + " private %s(final Logger logger) {%n"
119 + " super((AbstractLogger) logger, logger.getName(), logger.getMessageFactory());%n"
120 + " this.logger = this;%n"
121 + " }%n"
122 ;
123 }
124
125 Class<?> generator() {
126 return ExtendedLogger.class;
127 }
128 };
129 abstract String imports();
130
131 abstract String declaration();
132
133 abstract String constructor();
134
135 abstract Class<?> generator();
136 }
137
138 static final String FQCN_FIELD = ""
139 + " private static final String FQCN = %s.class.getName();%n";
140
141 static final String LEVEL_FIELD = ""
142 + " private static final Level %s = Level.forName(\"%s\", %d);%n";
143
144 static final String FACTORY_METHODS = ""
145 + "%n"
146 + " /**%n"
147 + " * Returns a custom Logger with the name of the calling class.%n"
148 + " * %n"
149 + " * @return The custom Logger for the calling class.%n"
150 + " */%n"
151 + " public static CLASSNAME create() {%n"
152 + " final Logger wrapped = LogManager.getLogger();%n"
153 + " return new CLASSNAME(wrapped);%n"
154 + " }%n"
155 + "%n"
156 + " /**%n"
157 + " * Returns a custom Logger using the fully qualified name of the Class as%n"
158 + " * the Logger name.%n"
159 + " * %n"
160 + " * @param loggerName The Class whose name should be used as the Logger name.%n"
161 + " * If null it will default to the calling class.%n"
162 + " * @return The custom Logger.%n"
163 + " */%n"
164 + " public static CLASSNAME create(final Class<?> loggerName) {%n"
165 + " final Logger wrapped = LogManager.getLogger(loggerName);%n"
166 + " return new CLASSNAME(wrapped);%n"
167 + " }%n"
168 + "%n"
169 + " /**%n"
170 + " * Returns a custom Logger using the fully qualified name of the Class as%n"
171 + " * the Logger name.%n"
172 + " * %n"
173 + " * @param loggerName The Class whose name should be used as the Logger name.%n"
174 + " * If null it will default to the calling class.%n"
175 + " * @param messageFactory The message factory is used only when creating a%n"
176 + " * logger, subsequent use does not change the logger but will log%n"
177 + " * a warning if mismatched.%n"
178 + " * @return The custom Logger.%n"
179 + " */%n"
180 + " public static CLASSNAME create(final Class<?> loggerName, final MessageFactory factory) {%n"
181 + " final Logger wrapped = LogManager.getLogger(loggerName, factory);%n"
182 + " return new CLASSNAME(wrapped);%n"
183 + " }%n"
184 + "%n"
185 + " /**%n"
186 + " * Returns a custom Logger using the fully qualified class name of the value%n"
187 + " * as the Logger name.%n"
188 + " * %n"
189 + " * @param value The value whose class name should be used as the Logger%n"
190 + " * name. If null the name of the calling class will be used as%n"
191 + " * the logger name.%n"
192 + " * @return The custom Logger.%n"
193 + " */%n"
194 + " public static CLASSNAME create(final Object value) {%n"
195 + " final Logger wrapped = LogManager.getLogger(value);%n"
196 + " return new CLASSNAME(wrapped);%n"
197 + " }%n"
198 + "%n"
199 + " /**%n"
200 + " * Returns a custom Logger using the fully qualified class name of the value%n"
201 + " * as the Logger name.%n"
202 + " * %n"
203 + " * @param value The value whose class name should be used as the Logger%n"
204 + " * name. If null the name of the calling class will be used as%n"
205 + " * the logger name.%n"
206 + " * @param messageFactory The message factory is used only when creating a%n"
207 + " * logger, subsequent use does not change the logger but will log%n"
208 + " * a warning if mismatched.%n"
209 + " * @return The custom Logger.%n"
210 + " */%n"
211 + " public static CLASSNAME create(final Object value, final MessageFactory factory) {%n"
212 + " final Logger wrapped = LogManager.getLogger(value, factory);%n"
213 + " return new CLASSNAME(wrapped);%n"
214 + " }%n"
215 + "%n"
216 + " /**%n"
217 + " * Returns a custom Logger with the specified name.%n"
218 + " * %n"
219 + " * @param name The logger name. If null the name of the calling class will%n"
220 + " * be used.%n"
221 + " * @return The custom Logger.%n"
222 + " */%n"
223 + " public static CLASSNAME create(final String name) {%n"
224 + " final Logger wrapped = LogManager.getLogger(name);%n"
225 + " return new CLASSNAME(wrapped);%n"
226 + " }%n"
227 + "%n"
228 + " /**%n"
229 + " * Returns a custom Logger with the specified name.%n"
230 + " * %n"
231 + " * @param name The logger name. If null the name of the calling class will%n"
232 + " * be used.%n"
233 + " * @param messageFactory The message factory is used only when creating a%n"
234 + " * logger, subsequent use does not change the logger but will log%n"
235 + " * a warning if mismatched.%n"
236 + " * @return The custom Logger.%n"
237 + " */%n"
238 + " public static CLASSNAME create(final String name, final MessageFactory factory) {%n"
239 + " final Logger wrapped = LogManager.getLogger(name, factory);%n"
240 + " return new CLASSNAME(wrapped);%n"
241 + " }%n"
242 ;
243 static final String METHODS = ""
244 + "%n"
245 + " /**%n"
246 + " * Logs a message with the specific Marker at the {@code CUSTOM_LEVEL} level.%n"
247 + " * %n"
248 + " * @param marker the marker data specific to this log statement%n"
249 + " * @param msg the message string to be logged%n"
250 + " */%n"
251 + " public void methodName(final Marker marker, final Message msg) {%n"
252 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, msg, (Throwable) null);%n"
253 + " }%n"
254 + "%n"
255 + " /**%n"
256 + " * Logs a message with the specific Marker at the {@code CUSTOM_LEVEL} level.%n"
257 + " * %n"
258 + " * @param marker the marker data specific to this log statement%n"
259 + " * @param msg the message string to be logged%n"
260 + " * @param t A Throwable or null.%n"
261 + " */%n"
262 + " public void methodName(final Marker marker, final Message msg, final Throwable t) {%n"
263 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, msg, t);%n"
264 + " }%n"
265 + "%n"
266 + " /**%n"
267 + " * Logs a message object with the {@code CUSTOM_LEVEL} level.%n"
268 + " * %n"
269 + " * @param marker the marker data specific to this log statement%n"
270 + " * @param message the message object to log.%n"
271 + " */%n"
272 + " public void methodName(final Marker marker, final Object message) {%n"
273 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, message, (Throwable) null);%n"
274 + " }%n"
275 + "%n"
276 + " /**%n"
277 + " * Logs a message at the {@code CUSTOM_LEVEL} level including the stack trace of%n"
278 + " * the {@link Throwable} {@code t} passed as parameter.%n"
279 + " * %n"
280 + " * @param marker the marker data specific to this log statement%n"
281 + " * @param message the message to log.%n"
282 + " * @param t the exception to log, including its stack trace.%n"
283 + " */%n"
284 + " public void methodName(final Marker marker, final Object message, final Throwable t) {%n"
285 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, message, t);%n"
286 + " }%n"
287 + "%n"
288 + " /**%n"
289 + " * Logs a message object with the {@code CUSTOM_LEVEL} level.%n"
290 + " * %n"
291 + " * @param marker the marker data specific to this log statement%n"
292 + " * @param message the message object to log.%n"
293 + " */%n"
294 + " public void methodName(final Marker marker, final String message) {%n"
295 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, message, (Throwable) null);%n"
296 + " }%n"
297 + "%n"
298 + " /**%n"
299 + " * Logs a message with parameters at the {@code CUSTOM_LEVEL} level.%n"
300 + " * %n"
301 + " * @param marker the marker data specific to this log statement%n"
302 + " * @param message the message to log; the format depends on the message factory.%n"
303 + " * @param params parameters to the message.%n"
304 + " * @see #getMessageFactory()%n"
305 + " */%n"
306 + " public void methodName(final Marker marker, final String message, final Object... params) {%n"
307 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, message, params);%n"
308 + " }%n"
309 + "%n"
310 + " /**%n"
311 + " * Logs a message at the {@code CUSTOM_LEVEL} level including the stack trace of%n"
312 + " * the {@link Throwable} {@code t} passed as parameter.%n"
313 + " * %n"
314 + " * @param marker the marker data specific to this log statement%n"
315 + " * @param message the message to log.%n"
316 + " * @param t the exception to log, including its stack trace.%n"
317 + " */%n"
318 + " public void methodName(final Marker marker, final String message, final Throwable t) {%n"
319 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, marker, message, t);%n"
320 + " }%n"
321 + "%n"
322 + " /**%n"
323 + " * Logs the specified Message at the {@code CUSTOM_LEVEL} level.%n"
324 + " * %n"
325 + " * @param msg the message string to be logged%n"
326 + " */%n"
327 + " public void methodName(final Message msg) {%n"
328 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, msg, (Throwable) null);%n"
329 + " }%n"
330 + "%n"
331 + " /**%n"
332 + " * Logs the specified Message at the {@code CUSTOM_LEVEL} level.%n"
333 + " * %n"
334 + " * @param msg the message string to be logged%n"
335 + " * @param t A Throwable or null.%n"
336 + " */%n"
337 + " public void methodName(final Message msg, final Throwable t) {%n"
338 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, msg, t);%n"
339 + " }%n"
340 + "%n"
341 + " /**%n"
342 + " * Logs a message object with the {@code CUSTOM_LEVEL} level.%n"
343 + " * %n"
344 + " * @param message the message object to log.%n"
345 + " */%n"
346 + " public void methodName(final Object message) {%n"
347 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, message, (Throwable) null);%n"
348 + " }%n"
349 + "%n"
350 + " /**%n"
351 + " * Logs a message at the {@code CUSTOM_LEVEL} level including the stack trace of%n"
352 + " * the {@link Throwable} {@code t} passed as parameter.%n"
353 + " * %n"
354 + " * @param message the message to log.%n"
355 + " * @param t the exception to log, including its stack trace.%n"
356 + " */%n"
357 + " public void methodName(final Object message, final Throwable t) {%n"
358 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, message, t);%n"
359 + " }%n"
360 + "%n"
361 + " /**%n"
362 + " * Logs a message object with the {@code CUSTOM_LEVEL} level.%n"
363 + " * %n"
364 + " * @param message the message object to log.%n"
365 + " */%n"
366 + " public void methodName(final String message) {%n"
367 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, message, (Throwable) null);%n"
368 + " }%n"
369 + "%n"
370 + " /**%n"
371 + " * Logs a message with parameters at the {@code CUSTOM_LEVEL} level.%n"
372 + " * %n"
373 + " * @param message the message to log; the format depends on the message factory.%n"
374 + " * @param params parameters to the message.%n"
375 + " * @see #getMessageFactory()%n"
376 + " */%n"
377 + " public void methodName(final String message, final Object... params) {%n"
378 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, message, params);%n"
379 + " }%n"
380 + "%n"
381 + " /**%n"
382 + " * Logs a message at the {@code CUSTOM_LEVEL} level including the stack trace of%n"
383 + " * the {@link Throwable} {@code t} passed as parameter.%n"
384 + " * %n"
385 + " * @param message the message to log.%n"
386 + " * @param t the exception to log, including its stack trace.%n"
387 + " */%n"
388 + " public void methodName(final String message, final Throwable t) {%n"
389 + " logger.logIfEnabled(FQCN, CUSTOM_LEVEL, null, message, t);%n"
390 + " }%n"
391 ;
392
393 private Generate() {
394 }
395
396
397
398
399
400 public static final class CustomLogger {
401
402
403
404
405
406
407
408 public static void main(final String[] args) {
409 generate(args, Type.CUSTOM);
410 }
411
412 private CustomLogger() {
413 }
414 }
415
416
417
418
419
420
421 public static final class ExtendedLogger {
422
423
424
425
426
427
428
429 public static void main(final String[] args) {
430 generate(args, Type.EXTEND);
431 }
432
433 private ExtendedLogger() {
434 }
435 }
436
437 static class LevelInfo {
438 final String name;
439 final int intLevel;
440
441 LevelInfo(final String description) {
442 final String[] parts = description.split("=");
443 name = parts[0];
444 intLevel = Integer.parseInt(parts[1]);
445 }
446
447 public static List<LevelInfo> parse(final List<String> values, final Class<?> generator) {
448 final List<LevelInfo> result = new ArrayList<Generate.LevelInfo>(values.size());
449 for (int i = 0; i < values.size(); i++) {
450 try {
451 result.add(new LevelInfo(values.get(i)));
452 } catch (Exception ex) {
453 System.err.println("Cannot parse custom level '" + values.get(i) + "': " + ex.toString());
454 usage(System.err, generator);
455 System.exit(-1);
456 }
457 }
458 return result;
459 }
460 }
461
462 private static void generate(final String[] args, final Type type) {
463 generate(args, type, System.out);
464 }
465
466 static void generate(final String[] args, final Type type, final PrintStream printStream) {
467 if (!validate(args)) {
468 usage(printStream, type.generator());
469 System.exit(-1);
470 }
471 final List<String> values = new ArrayList<String>(Arrays.asList(args));
472 final String classFQN = values.remove(0);
473 final List<LevelInfo> levels = LevelInfo.parse(values, type.generator());
474 printStream.println(generateSource(classFQN, levels, type));
475 }
476
477 static boolean validate(final String[] args) {
478 if (args.length < 2) {
479 return false;
480 }
481 return true;
482 }
483
484 private static void usage(final PrintStream out, final Class<?> generator) {
485 out.println("Usage: java " + generator.getName() + " className LEVEL1=intLevel1 [LEVEL2=intLevel2...]");
486 out.println(" Where className is the fully qualified class name of the custom/extended logger to generate,");
487 out.println(" followed by a space-separated list of custom log levels.");
488 out.println(" For each custom log level, specify NAME=intLevel (without spaces).");
489 }
490
491 static String generateSource(final String classNameFQN, final List<LevelInfo> levels, final Type type) {
492 final StringBuilder sb = new StringBuilder(10000 * levels.size());
493 final int lastDot = classNameFQN.lastIndexOf('.');
494 final String pkg = classNameFQN.substring(0, lastDot >= 0 ? lastDot : 0);
495 if (!pkg.isEmpty()) {
496 sb.append(String.format(PACKAGE_DECLARATION, pkg));
497 }
498 sb.append(String.format(type.imports(), ""));
499 final String className = classNameFQN.substring(classNameFQN.lastIndexOf('.') + 1);
500 final String javadocDescr = javadocDescription(levels);
501 sb.append(String.format(type.declaration(), javadocDescr, className));
502 sb.append(String.format(FQCN_FIELD, className));
503 for (LevelInfo level : levels) {
504 sb.append(String.format(LEVEL_FIELD, level.name, level.name, level.intLevel));
505 }
506 sb.append(String.format(type.constructor(), className));
507 sb.append(String.format(FACTORY_METHODS.replaceAll("CLASSNAME", className), ""));
508 for (LevelInfo level : levels) {
509 final String methodName = camelCase(level.name);
510 final String phase1 = METHODS.replaceAll("CUSTOM_LEVEL", level.name);
511 final String phase2 = phase1.replaceAll("methodName", methodName);
512 sb.append(String.format(phase2, ""));
513 }
514
515 sb.append(String.format("}%n", ""));
516 return sb.toString();
517 }
518
519 static String javadocDescription(final List<LevelInfo> levels) {
520 if (levels.size() == 1) {
521 return "the " + levels.get(0).name + " custom log level.";
522 }
523 final StringBuilder sb = new StringBuilder(512);
524 sb.append("the ");
525 String sep = "";
526 for (int i = 0; i < levels.size(); i++) {
527 sb.append(sep);
528 sb.append(levels.get(i).name);
529 sep = (i == levels.size() - 2) ? " and " : ", ";
530 }
531 sb.append(" custom log levels.");
532 return sb.toString();
533 }
534
535 static String camelCase(final String customLevel) {
536 final StringBuilder sb = new StringBuilder(customLevel.length());
537 boolean lower = true;
538 for (char ch : customLevel.toCharArray()) {
539 if (ch == '_') {
540 lower = false;
541 continue;
542 }
543 sb.append(lower ? Character.toLowerCase(ch) : Character.toUpperCase(ch));
544 lower = true;
545 }
546 return sb.toString();
547 }
548 }