Log4j configuration watcher

diff --git a/org.argeo.cms/src/org/argeo/cms/internal/kernel/NodeLogger.java b/org.argeo.cms/src/org/argeo/cms/internal/kernel/NodeLogger.java
index 134ab26ab3d06b8f3a97bd81bc357b48dd11c342..045229ce1fc81eadfe7fb8bade2e317c4f99270f 100644 (file)
--- a/org.argeo.cms/src/org/argeo/cms/internal/kernel/NodeLogger.java
+++ b/org.argeo.cms/src/org/argeo/cms/internal/kernel/NodeLogger.java
@@ -15,6 +15,14 @@
  */
 package org.argeo.cms.internal.kernel;
 
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardWatchEventKinds;
+import java.nio.file.WatchEvent;
+import java.nio.file.WatchKey;
+import java.nio.file.WatchService;
 import java.security.SignatureException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -53,6 +61,10 @@ import org.osgi.service.log.LogService;
 
 /** Not meant to be used directly in standard log4j config */
 class NodeLogger implements ArgeoLogger, LogListener {
+       /** Internal debug for development purposes. */
+       private static Boolean debug = false;
+
+       // private final static Log log = LogFactory.getLog(NodeLogger.class);
 
        private Boolean disabled = false;
 
@@ -92,6 +104,24 @@ class NodeLogger implements ArgeoLogger, LogListener {
                while (logEntries.hasMoreElements())
                        logged(logEntries.nextElement());
                lrs.addLogListener(this);
+
+               // configure log4j watcher
+               String log4jConfiguration = KernelUtils.getFrameworkProp("log4j.configuration");
+               if (log4jConfiguration != null && log4jConfiguration.startsWith("file:")) {
+                       if (log4jConfiguration.contains("..")) {
+                               if (log4jConfiguration.startsWith("file://"))
+                                       log4jConfiguration = log4jConfiguration.substring("file://".length());
+                               else if (log4jConfiguration.startsWith("file:"))
+                                       log4jConfiguration = log4jConfiguration.substring("file:".length());
+                       }
+                       try {
+                               Path log4jconfigPath = Paths.get(log4jConfiguration);
+                               Thread log4jConfWatcher = new Log4jConfWatcherThread(log4jconfigPath);
+                               log4jConfWatcher.start();
+                       } catch (Exception e) {
+                               stdErr("Badly formatted log4j configuration URI " + log4jConfiguration + ": " + e.getMessage());
+                       }
+               }
        }
 
        public void init() {
@@ -275,10 +305,23 @@ class NodeLogger implements ArgeoLogger, LogListener {
        }
 
        /** For development purpose, since using regular logging is not easy here */
-       static void stdOut(Object obj) {
+       private static void stdOut(Object obj) {
                System.out.println(obj);
        }
 
+       private static void stdErr(Object obj) {
+               System.err.println(obj);
+       }
+
+       private static void debug(Object obj) {
+               if (debug)
+                       System.out.println(obj);
+       }
+
+       private static boolean isInternalDebugEnabled() {
+               return debug;
+       }
+
        // public void setPattern(String pattern) {
        // this.pattern = pattern;
        // }
@@ -463,4 +506,43 @@ class NodeLogger implements ArgeoLogger, LogListener {
                }
 
        }
+
+       private class Log4jConfWatcherThread extends Thread {
+               private Path log4jConfigurationPath;
+
+               public Log4jConfWatcherThread(Path log4jConfigurationPath) {
+                       super("Log4j Configuration Watcher");
+                       try {
+                               this.log4jConfigurationPath = log4jConfigurationPath.toRealPath();
+                       } catch (IOException e) {
+                               this.log4jConfigurationPath = log4jConfigurationPath.toAbsolutePath();
+                               stdOut("Cannot determine real path for " + log4jConfigurationPath + ": " + e.getMessage());
+                       }
+               }
+
+               public void run() {
+                       Path parentDir = log4jConfigurationPath.getParent();
+                       try (final WatchService watchService = FileSystems.getDefault().newWatchService()) {
+                               parentDir.register(watchService, StandardWatchEventKinds.ENTRY_MODIFY);
+                               WatchKey wk;
+                               watching: while ((wk = watchService.take()) != null) {
+                                       for (WatchEvent<?> event : wk.pollEvents()) {
+                                               final Path changed = (Path) event.context();
+                                               if (log4jConfigurationPath.equals(parentDir.resolve(changed))) {
+                                                       if (isInternalDebugEnabled())
+                                                               debug(log4jConfigurationPath + " has changed, reloading.");
+                                                       PropertyConfigurator.configure(log4jConfigurationPath.toUri().toURL());
+                                               }
+                                       }
+                                       // reset the key
+                                       boolean valid = wk.reset();
+                                       if (!valid) {
+                                               break watching;
+                                       }
+                               }
+                       } catch (IOException | InterruptedException e) {
+                               stdErr("Log4j configuration watcher failed: " + e.getMessage());
+                       }
+               }
+       }
 }