这里面包含了一百多个JAVA源文件

				When an application is terminated normally, the application first starts any registered shutdown threads, waits for them to complete and then finally exits. Normal termination can be caused by a call to System.exit(), the completion of the last non-daemon thread, or the interruption of the application (control-C) by the user. Abnormal termination (which does not cause the shutdown threads to be started) is caused some major fault in the Java virtual machine or native library. 
				    // Register a shutdown thread
				    Runtime.getRuntime().addShutdownHook(new Thread() {
				        // This method is called during shutdown
				        public void run() {
				            // Do shutdown work ...
				        }
				    });