ServiceHelper: fall back to stderr if there is no LogService yet

dscho · dscho · commit a6b68aa1f94d · 2013-03-24T22:17:43.000-05:00
At the stage of the ServiceHelper, we cannot realistically assume
that the LogService has been created yet: there might have been an
error initializing it, it might not have been initialized yet, or
there might not be any LogService available to begin with.

We should fail gracefully in all those cases and simply fall back to
printing to stderr instead.

Signed-off-by: Johannes Schindelin &lt;johannes.schindelin@gmx.de&gt;
diff --git a/src/main/java/org/scijava/service/ServiceHelper.java b/src/main/java/org/scijava/service/ServiceHelper.java
@@ -229,24 +229,34 @@ private void findServiceClasses(
 	private void info(final String msg) {
 		final LogService log = getContext().getService(LogService.class);
 		if (log != null) log.info(msg);
+		else System.err.println("[INFO] " + msg);
 	}
 	
 	/** Logs the given warning, if a {@link LogService} is available. */ 
 	private void warn(final String msg) {
 		final LogService log = getContext().getService(LogService.class);
 		if (log != null) log.warn(msg);
+		else System.err.println("[WARNING] " + msg);
 	}
 
 	/** Logs the given error, if a {@link LogService} is available. */
 	private void error(final String msg, final Throwable t) {
 		final LogService log = getContext().getService(LogService.class);
 		if (log != null) log.error(msg, t);
+		else {
+			System.err.println("[ERROR] " + msg);
+			if (t != null) t.printStackTrace();
+		}
 	}
 
 	/** Logs the given debug message, if a {@link LogService} is available. */
 	private void debug(final String msg, final Throwable t) {
 		final LogService log = getContext().getService(LogService.class);
 		if (log != null) log.debug(msg, t);
+		else {
+			System.err.println("[DEBUG] " + msg);
+			if (t != null) t.printStackTrace();
+		}
 	}
 
 }
