Changeset 31644 for main/trunk

Timestamp:

2017-05-03T17:36:02+12:00 (7 years ago)

Author:

ak19

Message:

Learnt about shutdown hooks in Java. Adding one to GLI (Gatherer) to issue the ant call to stop the GS3 server (tomcat and derby) on unexpected termination of GLI, such as Ctrl-C.

File:

• main/trunk/gli/src/org/greenstone/gatherer/Gatherer.java (modified) (1 diff)

main/trunk/gli/src/org/greenstone/gatherer/Gatherer.java

@@ -388 +388 @@
                     GS3ServerThread thread = new GS3ServerThread(gsdl3_src_path, "restart");
                     thread.start();
+    
+                    // The Java virtual machine shuts down in response to two kinds of events:
+                    // - The program exits normally, when the last non-daemon thread exits or when the exit (equivalently, System.exit) method is invoked, or
+                    // - The virtual machine is terminated in response to a user interrupt, such as typing ^C, or a system-wide event, such as user logoff or system shutdown.
+                    // https://coderanch.com/t/328888/java/Killing-process-spawned-Runtime-exec
+                    Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
+                        public void run() {                     
+
+                            if(Gatherer.exit != true) { // unexpected termination, such as Ctrl-C won't set Gatherer.exit
+                            // so still need to at least issue the ant call to stop any running GS3
+                            // (tomcat and networked Derby Server) by calling GS3ServerThread.stopServer()
+                            System.err.println("ShutDownHook called...");
+                            System.err.println("Attempting to forcibly terminate the GS3 server...");
+                            GS3ServerThread.stopServer();
+                            }
+                        }
+                        }));
+                    
+
 
                     // If fedora installed inside this local GS3, then ask for fedora login details now.