Classloading issue (#1069)

Kieker.WebGUI/src/main/java/kieker/webgui/common/EnvironmentLoaderListener.java

@@ -22,14 +22,17 @@ import javax.servlet.ServletContextListener;
 import kieker.common.logging.Log;
 import kieker.common.logging.LogFactory;
 
+import org.eclipse.emf.common.util.CommonUtil;
+
 /**
  * This is a context listener, which will be activated during the initialization of the application. It initializes some environment properties, which are necessary
  * for the web application.<br>
  * </br>
  * 
- * The only environment property which is currently set by this listener is the property for the web application logger. This makes sure that later created analyses
- * use the correct logger, whose messages can be intercepted by this application. If this environment property is not set, the log entries of the analyses cannot be
- * shown in the corresponding control panel.<br>
+ * The only two environment properties, which are currently set by this listener are the property for the web application logger and the property for the EMF cleaner
+ * thread. The first ones makes sure that later created analyses use the correct logger, whose messages can be intercepted by this application. If this environment
+ * property is not set, the log entries of the analyses cannot be shown in the corresponding control panel. The second property makes sure that later created
+ * analyses do not start a cleaner thread, which would result in further problems with the hot deployment and the GC.<br>
  * </br>
  * 
  * As this class is used by the servlet container, it is <b>not</b> recommended to use or access it in any way.
@@ -54,12 +57,12 @@ public final class EnvironmentLoaderListener implements ServletContextListener {
 
 	@Override
 	public void contextInitialized(final ServletContextEvent event) {
-		// We have to use the logger before setting the environment property. This makes sure, that our own logger is not initialized with the web application
-		// logger. All components which are created later use the correct logger though (they are loaded with another class loader and use another instance of the
-		// logging factory class therefore).
 		LOG.info("Starting Kieker.WebGUI environment initialization.");
 		final long timeIn = System.currentTimeMillis();
 
+		// We have to use some classes before setting the environment properties. This makes sure that the classes used within the WebGUI are initialized without
+		// these environments. The later created classes use another class loader and are therefore initialized with the modified environment settings.
+		this.initializeClasses();
 		this.initializeProperties();
 
 		final long timeOut = System.currentTimeMillis();
@@ -68,8 +71,14 @@ public final class EnvironmentLoaderListener implements ServletContextListener {
 		LOG.info(String.format("Kieker.WebGUI environment initialized in %d ms.", timeDelta));
 	}
 
+	private void initializeClasses() {
+		// The Log class has already been initialized. All that remains is the CommonUtil class.
+		CommonUtil.internToUpperCase(null);
+	}
+
 	private void initializeProperties() {
 		System.setProperty("kieker.common.logging.Log", "WEBGUI");
+		System.setProperty("org.eclipse.emf.common.util.ReferenceClearingQueue", "false");
 	}
 
 }