1 /*
2 * Copyright 2013 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. You may obtain a copy of the License at:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 /**
17 * Copyright (c) 2004-2011 QOS.ch
18 * All rights reserved.
19 *
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
27 *
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
30 *
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
38 *
39 */
40 package io.netty.util.internal.logging;
41
42 import java.text.MessageFormat;
43 import java.util.HashSet;
44 import java.util.Set;
45
46 // contributors: lizongbo: proposed special treatment of array parameter values
47 // Joern Huxhorn: pointed out double[] omission, suggested deep array copy
48
49 /**
50 * Formats messages according to very simple substitution rules. Substitutions
51 * can be made 1, 2 or more arguments.
52 * <p/>
53 * <p/>
54 * For example,
55 * <p/>
56 * <pre>
57 * MessageFormatter.format("Hi {}.", "there")
58 * </pre>
59 * <p/>
60 * will return the string "Hi there.".
61 * <p/>
62 * The {} pair is called the <em>formatting anchor</em>. It serves to designate
63 * the location where arguments need to be substituted within the message
64 * pattern.
65 * <p/>
66 * In case your message contains the '{' or the '}' character, you do not have
67 * to do anything special unless the '}' character immediately follows '{'. For
68 * example,
69 * <p/>
70 * <pre>
71 * MessageFormatter.format("Set {1,2,3} is not equal to {}.", "1,2");
72 * </pre>
73 * <p/>
74 * will return the string "Set {1,2,3} is not equal to 1,2.".
75 * <p/>
76 * <p/>
77 * If for whatever reason you need to place the string "{}" in the message
78 * without its <em>formatting anchor</em> meaning, then you need to escape the
79 * '{' character with '\', that is the backslash character. Only the '{'
80 * character should be escaped. There is no need to escape the '}' character.
81 * For example,
82 * <p/>
83 * <pre>
84 * MessageFormatter.format("Set \\{} is not equal to {}.", "1,2");
85 * </pre>
86 * <p/>
87 * will return the string "Set {} is not equal to 1,2.".
88 * <p/>
89 * <p/>
90 * The escaping behavior just described can be overridden by escaping the escape
91 * character '\'. Calling
92 * <p/>
93 * <pre>
94 * MessageFormatter.format("File name is C:\\\\{}.", "file.zip");
95 * </pre>
96 * <p/>
97 * will return the string "File name is C:\file.zip".
98 * <p/>
99 * <p/>
100 * The formatting conventions are different than those of {@link MessageFormat}
101 * which ships with the Java platform. This is justified by the fact that
102 * SLF4J's implementation is 10 times faster than that of {@link MessageFormat}.
103 * This local performance difference is both measurable and significant in the
104 * larger context of the complete logging processing chain.
105 * <p/>
106 * <p/>
107 * See also {@link #format(String, Object)},
108 * {@link #format(String, Object, Object)} and
109 * {@link #arrayFormat(String, Object[])} methods for more details.
110 */
111 final class MessageFormatter {
112 private static final String DELIM_STR = "{}";
113 private static final char ESCAPE_CHAR = '\\';
114
115 /**
116 * Performs single argument substitution for the 'messagePattern' passed as
117 * parameter.
118 * <p/>
119 * For example,
120 * <p/>
121 * <pre>
122 * MessageFormatter.format("Hi {}.", "there");
123 * </pre>
124 * <p/>
125 * will return the string "Hi there.".
126 * <p/>
127 *
128 * @param messagePattern The message pattern which will be parsed and formatted
129 * @param arg The argument to be substituted in place of the formatting anchor
130 * @return The formatted message
131 */
132 static FormattingTuple format(String messagePattern, Object arg) {
133 return arrayFormat(messagePattern, new Object[]{arg});
134 }
135
136 /**
137 * Performs a two argument substitution for the 'messagePattern' passed as
138 * parameter.
139 * <p/>
140 * For example,
141 * <p/>
142 * <pre>
143 * MessageFormatter.format("Hi {}. My name is {}.", "Alice", "Bob");
144 * </pre>
145 * <p/>
146 * will return the string "Hi Alice. My name is Bob.".
147 *
148 * @param messagePattern The message pattern which will be parsed and formatted
149 * @param argA The argument to be substituted in place of the first formatting
150 * anchor
151 * @param argB The argument to be substituted in place of the second formatting
152 * anchor
153 * @return The formatted message
154 */
155 static FormattingTuple format(final String messagePattern,
156 Object argA, Object argB) {
157 return arrayFormat(messagePattern, new Object[]{argA, argB});
158 }
159
160 /**
161 * Same principle as the {@link #format(String, Object)} and
162 * {@link #format(String, Object, Object)} methods except that any number of
163 * arguments can be passed in an array.
164 *
165 * @param messagePattern The message pattern which will be parsed and formatted
166 * @param argArray An array of arguments to be substituted in place of formatting
167 * anchors
168 * @return The formatted message
169 */
170 static FormattingTuple arrayFormat(final String messagePattern,
171 final Object[] argArray) {
172 if (argArray == null || argArray.length == 0) {
173 return new FormattingTuple(messagePattern, null);
174 }
175
176 int lastArrIdx = argArray.length - 1;
177 Object lastEntry = argArray[lastArrIdx];
178 Throwable throwable = lastEntry instanceof Throwable? (Throwable) lastEntry : null;
179
180 if (messagePattern == null) {
181 return new FormattingTuple(null, throwable);
182 }
183
184 int j = messagePattern.indexOf(DELIM_STR);
185 if (j == -1) {
186 // this is a simple string
187 return new FormattingTuple(messagePattern, throwable);
188 }
189
190 StringBuilder sbuf = new StringBuilder(messagePattern.length() + 50);
191 int i = 0;
192 int L = 0;
193 do {
194 boolean notEscaped = j == 0 || messagePattern.charAt(j - 1) != ESCAPE_CHAR;
195 if (notEscaped) {
196 // normal case
197 sbuf.append(messagePattern, i, j);
198 } else {
199 sbuf.append(messagePattern, i, j - 1);
200 // check that escape char is not is escaped: "abc x:\\{}"
201 notEscaped = j >= 2 && messagePattern.charAt(j - 2) == ESCAPE_CHAR;
202 }
203
204 i = j + 2;
205 if (notEscaped) {
206 deeplyAppendParameter(sbuf, argArray[L], null);
207 L++;
208 if (L > lastArrIdx) {
209 break;
210 }
211 } else {
212 sbuf.append(DELIM_STR);
213 }
214 j = messagePattern.indexOf(DELIM_STR, i);
215 } while (j != -1);
216
217 // append the characters following the last {} pair.
218 sbuf.append(messagePattern, i, messagePattern.length());
219 return new FormattingTuple(sbuf.toString(), L <= lastArrIdx? throwable : null);
220 }
221
222 // special treatment of array values was suggested by 'lizongbo'
223 private static void deeplyAppendParameter(StringBuilder sbuf, Object o,
224 Set<Object[]> seenSet) {
225 if (o == null) {
226 sbuf.append("null");
227 return;
228 }
229 Class<?> objClass = o.getClass();
230 if (!objClass.isArray()) {
231 if (Number.class.isAssignableFrom(objClass)) {
232 // Prevent String instantiation for some number types
233 if (objClass == Long.class) {
234 sbuf.append(((Long) o).longValue());
235 } else if (objClass == Integer.class || objClass == Short.class || objClass == Byte.class) {
236 sbuf.append(((Number) o).intValue());
237 } else if (objClass == Double.class) {
238 sbuf.append(((Double) o).doubleValue());
239 } else if (objClass == Float.class) {
240 sbuf.append(((Float) o).floatValue());
241 } else {
242 safeObjectAppend(sbuf, o);
243 }
244 } else {
245 safeObjectAppend(sbuf, o);
246 }
247 } else {
248 // check for primitive array types because they
249 // unfortunately cannot be cast to Object[]
250 sbuf.append('[');
251 if (objClass == boolean[].class) {
252 booleanArrayAppend(sbuf, (boolean[]) o);
253 } else if (objClass == byte[].class) {
254 byteArrayAppend(sbuf, (byte[]) o);
255 } else if (objClass == char[].class) {
256 charArrayAppend(sbuf, (char[]) o);
257 } else if (objClass == short[].class) {
258 shortArrayAppend(sbuf, (short[]) o);
259 } else if (objClass == int[].class) {
260 intArrayAppend(sbuf, (int[]) o);
261 } else if (objClass == long[].class) {
262 longArrayAppend(sbuf, (long[]) o);
263 } else if (objClass == float[].class) {
264 floatArrayAppend(sbuf, (float[]) o);
265 } else if (objClass == double[].class) {
266 doubleArrayAppend(sbuf, (double[]) o);
267 } else {
268 objectArrayAppend(sbuf, (Object[]) o, seenSet);
269 }
270 sbuf.append(']');
271 }
272 }
273
274 private static void safeObjectAppend(StringBuilder sbuf, Object o) {
275 try {
276 String oAsString = o.toString();
277 sbuf.append(oAsString);
278 } catch (Throwable t) {
279 System.err
280 .println("SLF4J: Failed toString() invocation on an object of type ["
281 + o.getClass().getName() + ']');
282 t.printStackTrace();
283 sbuf.append("[FAILED toString()]");
284 }
285 }
286
287 private static void objectArrayAppend(StringBuilder sbuf, Object[] a, Set<Object[]> seenSet) {
288 if (a.length == 0) {
289 return;
290 }
291 if (seenSet == null) {
292 seenSet = new HashSet<Object[]>(a.length);
293 }
294 if (seenSet.add(a)) {
295 deeplyAppendParameter(sbuf, a[0], seenSet);
296 for (int i = 1; i < a.length; i++) {
297 sbuf.append(", ");
298 deeplyAppendParameter(sbuf, a[i], seenSet);
299 }
300 // allow repeats in siblings
301 seenSet.remove(a);
302 } else {
303 sbuf.append("...");
304 }
305 }
306
307 private static void booleanArrayAppend(StringBuilder sbuf, boolean[] a) {
308 if (a.length == 0) {
309 return;
310 }
311 sbuf.append(a[0]);
312 for (int i = 1; i < a.length; i++) {
313 sbuf.append(", ");
314 sbuf.append(a[i]);
315 }
316 }
317
318 private static void byteArrayAppend(StringBuilder sbuf, byte[] a) {
319 if (a.length == 0) {
320 return;
321 }
322 sbuf.append(a[0]);
323 for (int i = 1; i < a.length; i++) {
324 sbuf.append(", ");
325 sbuf.append(a[i]);
326 }
327 }
328
329 private static void charArrayAppend(StringBuilder sbuf, char[] a) {
330 if (a.length == 0) {
331 return;
332 }
333 sbuf.append(a[0]);
334 for (int i = 1; i < a.length; i++) {
335 sbuf.append(", ");
336 sbuf.append(a[i]);
337 }
338 }
339
340 private static void shortArrayAppend(StringBuilder sbuf, short[] a) {
341 if (a.length == 0) {
342 return;
343 }
344 sbuf.append(a[0]);
345 for (int i = 1; i < a.length; i++) {
346 sbuf.append(", ");
347 sbuf.append(a[i]);
348 }
349 }
350
351 private static void intArrayAppend(StringBuilder sbuf, int[] a) {
352 if (a.length == 0) {
353 return;
354 }
355 sbuf.append(a[0]);
356 for (int i = 1; i < a.length; i++) {
357 sbuf.append(", ");
358 sbuf.append(a[i]);
359 }
360 }
361
362 private static void longArrayAppend(StringBuilder sbuf, long[] a) {
363 if (a.length == 0) {
364 return;
365 }
366 sbuf.append(a[0]);
367 for (int i = 1; i < a.length; i++) {
368 sbuf.append(", ");
369 sbuf.append(a[i]);
370 }
371 }
372
373 private static void floatArrayAppend(StringBuilder sbuf, float[] a) {
374 if (a.length == 0) {
375 return;
376 }
377 sbuf.append(a[0]);
378 for (int i = 1; i < a.length; i++) {
379 sbuf.append(", ");
380 sbuf.append(a[i]);
381 }
382 }
383
384 private static void doubleArrayAppend(StringBuilder sbuf, double[] a) {
385 if (a.length == 0) {
386 return;
387 }
388 sbuf.append(a[0]);
389 for (int i = 1; i < a.length; i++) {
390 sbuf.append(", ");
391 sbuf.append(a[i]);
392 }
393 }
394
395 private MessageFormatter() {
396 }
397 }