DefaultLogger


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3    *  contributor license agreements.  See the NOTICE file distributed with
4    *  this work for additional information regarding copyright ownership.
5    *  The ASF licenses this file to You under the Apache License, Version 2.0
6    *  (the "License"); you may not use this file except in compliance with
7    *  the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   *
17   */
18  
19  package org.apache.tools.ant;
20  
21  import java.io.BufferedReader  ;
22  import java.io.IOException  ;
23  import java.io.PrintStream  ;
24  import java.io.StringReader  ;
25  
26  import org.apache.tools.ant.util.DateUtils;
27  import org.apache.tools.ant.util.StringUtils;
28  
29  /**
30   * Writes build events to a PrintStream. Currently, it
31   * only writes which targets are being executed, and
32   * any messages that get logged.
33   *
34   */
35  public class DefaultLogger implements BuildLogger {
36      /**
37       * Size of left-hand column for right-justified task name.
38       * @see #messageLogged(BuildEvent)
39       */
40      public static final int LEFT_COLUMN_SIZE = 12;
41  
42      // CheckStyle:VisibilityModifier OFF - bc
43      /** PrintStream to write non-error messages to */
44      protected PrintStream   out;
45  
46      /** PrintStream to write error messages to */
47      protected PrintStream   err;
48  
49      /** Lowest level of message to write out */
50      protected int msgOutputLevel = Project.MSG_ERR;
51  
52      /** Time of the start of the build */
53      private long startTime = System.currentTimeMillis();
54  
55      // CheckStyle:ConstantNameCheck OFF - bc
56      /** Line separator */
57      protected static final String   lSep = StringUtils.LINE_SEP;
58      // CheckStyle:ConstantNameCheck ON
59  
60      /** Whether or not to use emacs-style output */
61      protected boolean emacsMode = false;
62      // CheckStyle:VisibilityModifier ON
63  
64  
65      /**
66       * Sole constructor.
67       */
68      public DefaultLogger() {
69      }
70  
71      /**
72       * Sets the highest level of message this logger should respond to.
73       *
74       * Only messages with a message level lower than or equal to the
75       * given level should be written to the log.
76       * <p>
77       * Constants for the message levels are in the
78       * {@link Project Project} class. The order of the levels, from least
79       * to most verbose, is <code>MSG_ERR</code>, <code>MSG_WARN</code>,
80       * <code>MSG_INFO</code>, <code>MSG_VERBOSE</code>,
81       * <code>MSG_DEBUG</code>.
82       * <p>
83       * The default message level for DefaultLogger is Project.MSG_ERR.
84       *
85       * @param level the logging level for the logger.
86       */
87      public void setMessageOutputLevel(int level) {
88          this.msgOutputLevel = level;
89      }
90  
91      /**
92       * Sets the output stream to which this logger is to send its output.
93       *
94       * @param output The output stream for the logger.
95       *               Must not be <code>null</code>.
96       */
97      public void setOutputPrintStream(PrintStream   output) {
98          this.out = new PrintStream  (output, true);
99      }
100 
101     /**
102      * Sets the output stream to which this logger is to send error messages.
103      *
104      * @param err The error stream for the logger.
105      *            Must not be <code>null</code>.
106      */
107     public void setErrorPrintStream(PrintStream   err) {
108         this.err = new PrintStream  (err, true);
109     }
110 
111     /**
112      * Sets this logger to produce emacs (and other editor) friendly output.
113      *
114      * @param emacsMode <code>true</code> if output is to be unadorned so that
115      *                  emacs and other editors can parse files names, etc.
116      */
117     public void setEmacsMode(boolean emacsMode) {
118         this.emacsMode = emacsMode;
119     }
120 
121     /**
122      * Responds to a build being started by just remembering the current time.
123      *
124      * @param event Ignored.
125      */
126     public void buildStarted(BuildEvent event) {
127         startTime = System.currentTimeMillis();
128     }
129 
130     /**
131      * Prints whether the build succeeded or failed,
132      * any errors the occurred during the build, and
133      * how long the build took.
134      *
135      * @param event An event with any relevant extra information.
136      *              Must not be <code>null</code>.
137      */
138     public void buildFinished(BuildEvent event) {
139         Throwable   error = event.getException();
140         StringBuffer   message = new StringBuffer  ();
141         if (error == null) {
142             message.append(StringUtils.LINE_SEP);
143             message.append(getBuildSuccessfulMessage());
144         } else {
145             message.append(StringUtils.LINE_SEP);
146             message.append(getBuildFailedMessage());
147             message.append(StringUtils.LINE_SEP);
148 
149             if (Project.MSG_VERBOSE <= msgOutputLevel
150                 || !(error instanceof BuildException)) {
151                 message.append(StringUtils.getStackTrace(error));
152             } else {
153                 message.append(error.toString()).append(lSep);
154             }
155         }
156         message.append(StringUtils.LINE_SEP);
157         message.append("Total time: ");
158         message.append(formatTime(System.currentTimeMillis() - startTime));
159 
160         String   msg = message.toString();
161         if (error == null) {
162             printMessage(msg, out, Project.MSG_VERBOSE);
163         } else {
164             printMessage(msg, err, Project.MSG_ERR);
165         }
166         log(msg);
167     }
168 
169     /**
170      * This is an override point: the message that indicates whether a build failed.
171      * Subclasses can change/enhance the message.
172      * @return The classic "BUILD FAILED"
173      */
174     protected String   getBuildFailedMessage() {
175         return "BUILD FAILED";
176     }
177 
178     /**
179      * This is an override point: the message that indicates that a build succeeded.
180      * Subclasses can change/enhance the message.
181      * @return The classic "BUILD SUCCESSFUL"
182      */
183     protected String   getBuildSuccessfulMessage() {
184         return "BUILD SUCCESSFUL";
185     }
186 
187     /**
188      * Logs a message to say that the target has started if this
189      * logger allows information-level messages.
190      *
191      * @param event An event with any relevant extra information.
192      *              Must not be <code>null</code>.
193       */
194     public void targetStarted(BuildEvent event) {
195         if (Project.MSG_INFO <= msgOutputLevel
196             && !event.getTarget().getName().equals("")) {
197             String   msg = StringUtils.LINE_SEP
198                 + event.getTarget().getName() + ":";
199             printMessage(msg, out, event.getPriority());
200             log(msg);
201         }
202     }
203 
204     /**
205      * No-op implementation.
206      *
207      * @param event Ignored.
208      */
209     public void targetFinished(BuildEvent event) {
210     }
211 
212     /**
213      * No-op implementation.
214      *
215      * @param event Ignored.
216      */
217     public void taskStarted(BuildEvent event) {
218     }
219 
220     /**
221      * No-op implementation.
222      *
223      * @param event Ignored.
224      */
225     public void taskFinished(BuildEvent event) {
226     }
227 
228     /**
229      * Logs a message, if the priority is suitable.
230      * In non-emacs mode, task level messages are prefixed by the
231      * task name which is right-justified.
232      *
233      * @param event A BuildEvent containing message information.
234      *              Must not be <code>null</code>.
235      */
236     public void messageLogged(BuildEvent event) {
237         int priority = event.getPriority();
238         // Filter out messages based on priority
239         if (priority <= msgOutputLevel) {
240 
241             StringBuffer   message = new StringBuffer  ();
242             if (event.getTask() != null && !emacsMode) {
243                 // Print out the name of the task if we're in one
244                 String   name = event.getTask().getTaskName();
245                 String   label = "[" + name + "] ";
246                 int size = LEFT_COLUMN_SIZE - label.length();
247                 StringBuffer   tmp = new StringBuffer  ();
248                 for (int i = 0; i < size; i++) {
249                     tmp.append(" ");
250                 }
251                 tmp.append(label);
252                 label = tmp.toString();
253 
254                 try {
255                     BufferedReader   r =
256                         new BufferedReader  (
257                             new StringReader  (event.getMessage()));
258                     String   line = r.readLine();
259                     boolean first = true;
260                     do {
261                         if (first) {
262                             if (line == null) {
263                                 message.append(label);
264                                 break;
265                             }
266                         } else {
267                             message.append(StringUtils.LINE_SEP);
268                         }
269                         first = false;
270                         message.append(label).append(line);
271                         line = r.readLine();
272                     } while (line != null);
273                 } catch (IOException   e) {
274                     // shouldn't be possible
275                     message.append(label).append(event.getMessage());
276                 }
277             } else {
278                 message.append(event.getMessage());
279             }
280             Throwable   ex = event.getException();
281             if (Project.MSG_DEBUG <= msgOutputLevel && ex != null) {
282                     message.append(StringUtils.getStackTrace(ex));
283             }
284 
285             String   msg = message.toString();
286             if (priority != Project.MSG_ERR) {
287                 printMessage(msg, out, priority);
288             } else {
289                 printMessage(msg, err, priority);
290             }
291             log(msg);
292         }
293     }
294 
295     /**
296      * Convenience method to format a specified length of time.
297      *
298      * @param millis Length of time to format, in milliseconds.
299      *
300      * @return the time as a formatted string.
301      *
302      * @see DateUtils#formatElapsedTime(long)
303      */
304     protected static String   formatTime(final long millis) {
305         return DateUtils.formatElapsedTime(millis);
306     }
307 
308     /**
309      * Prints a message to a PrintStream.
310      *
311      * @param message  The message to print.
312      *                 Should not be <code>null</code>.
313      * @param stream   A PrintStream to print the message to.
314      *                 Must not be <code>null</code>.
315      * @param priority The priority of the message.
316      *                 (Ignored in this implementation.)
317      */
318     protected void printMessage(final String   message,
319                                 final PrintStream   stream,
320                                 final int priority) {
321         stream.println(message);
322     }
323 
324     /**
325      * Empty implementation which allows subclasses to receive the
326      * same output that is generated here.
327      *
328      * @param message Message being logged. Should not be <code>null</code>.
329      */
330     protected void log(String   message) {
331     }
332 }
333
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