In order to close Java program we need to consider which kind of Java application is it?, because termination of Java application varies between normal core java program to swing GUI application. In general all Java programs terminate automatically once all user threads created by program finishes its execution, including main thread.<\/p>\n
JVM doesn’t wait for daemon thread so as soon as last user thread finished, Java program will terminate. If you want to close or terminate your java application before this, your only option is to use This cause JVM to abandon all threads and exit immediately. Shutdown hooks are get called to allow some last minute clearing before JVM actually terminates. Unlike AWT, Java Swing provides platform-independent and lightweight components.\u00a0The javax.swing package provides classes for java swing API<\/p>\n Swing API architecture follows loosely based MVC architecture in the following manner.<\/p>\n Every user interface considers the following three main aspects:<\/p>\n Light Weight \u2013 Swing component are independent of native Operating System\u2019s API as Swing API controls are rendered mostly using pure JAVA code instead of underlying operating system calls.<\/p>\n Popular Java Editors: Prerequisite<\/b> Here is a code example of closing Java program by calling System.exit() method. Remember non zero argument to exit() method like exit(1) denotes abnormal termination of Java application.<\/p>\n ApplicationExit.java<\/em><\/span><\/p>\n This Java program first creates a Thread\u00a0 in main method and start it, \u00a0which prints \u201cUser thread is running\u201d and then main thread sleeps for 200 Milli second. Till then, the other user thread is running and printing but once the main thread wakes up, it terminates the program by calling Swing application mostly uses Difference between ApplicationExit.java<\/em><\/span><\/p>\n That’s all on how to close or terminate Java program. We have also seen example of closing Swing application in Java and difference between This was an example of closing a Java application properly.<\/p>\nSystem.exit(int status)<\/code> or Runtime.getRuntime().exit()<\/code>.<\/p>\nSystem.exit()<\/code> also accept an int status parameter where a non zero value denote abnormal execute and the result returned by java command to caller. In this java tutorial we will see example of closing both Java program and Java Swing application.
\nSwing is a GUI widget toolkit for Java. It is part of Oracle\u2019s Java Foundation Classes (JFC) \u2013 an API for providing a graphical user interface (GUI) for Java programs. Swing was developed to provide a more sophisticated set of GUI components than the earlier Abstract Window Toolkit (AWT)<\/code>. JAVA provides a rich set of libraries to create Graphical User Interface in platform independent way.<\/p>\n2. Java Swing<\/h2>\n
2.1 MVC Architecture<\/h3>\n
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2.2 Swing Features<\/h3>\n
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2.3 Setup<\/h3>\n
\nTo write your java programs you will need a text editor. There are even more sophisticated IDE available in the market. But for now, you can consider one of the following:\n
\nThis example is developed on Eclipse therefore a compatible Eclipse IDE is required to be installed on the system.
\nWe also need WindowBuilder tool to be installed on Eclipse IDE for the easiness of the work.<\/p>\n3. Example of Closing Java program using System.exit()<\/h2>\n
import java.util.logging.Level;\r\nimport java.util.logging.Logger;\r\n\r\n\/**\r\n\u00a0*Java program which terminates itself by using System.exit() method , non zero call to exit() method denotes abnormal termination.\r\n\u00a0*\/\r\npublic class JavaCloseExample {\r\n\u00a0 \r\n\u00a0 \u00a0 public static void main(String args[]) throws InterruptedException {\r\n\u00a0 \u00a0 \r\n\u00a0 \u00a0 \u00a0 \u00a0Thread t = new Thread(){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 @Override\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0public void run(){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0while(true){\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0System.out.println(\"User thread is running\");\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 try {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Thread.sleep(100);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 } catch (InterruptedException ex) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Logger.getLogger(JavaCloseExample.class.getName()).log(Level.SEVERE, null, ex);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0}\r\n\u00a0 \u00a0 \u00a0 \u00a0};\r\n\u00a0 \u00a0 \u00a0 \r\n\u00a0 \u00a0 \u00a0 \u00a0t.start();\r\n\u00a0 \u00a0 \u00a0 \u00a0Thread.sleep(200);\r\n\u00a0 \u00a0 \u00a0 \u00a0System.out.println(\"terminating or closing java program\");\r\n\u00a0 \u00a0 \u00a0 \u00a0System.exit(1); \/\/non zero value to exit says abnormal termination of JVM\r\n\u00a0 \u00a0 }\r\n}\r\n\r\nOutput:\r\nUser thread is running\r\nUser thread is running\r\nterminating or closing java program\r\nJava Result: 1 \u00a0\/\/1 is what we passed to exit() method\r\n\r\n<\/pre>\nexit()<\/code> method of java.lang.System<\/code> class.<\/p>\n3.2 How to close Java swing application from program<\/h3>\n
JFrame<\/code> as top level container which provides two option to close swing GUI application from code. First option which is default is EXIT_ON_CLOSE which terminates Java swing GUI program when you click close button on JFrame<\/code> window. Another option is DISPOSE_ON_CLOSE<\/code> which terminates JVM if last displayable window is disposed off.<\/p>\nEXIT_ON_CLOSE<\/code> and DISPOSE_ON_CLOSE<\/code> is that if you have a non daemon thread running it will not be closed in case of DISPOSE_ON_CLOSE<\/code>, while EXIT_ON_CLOSE<\/code> terminate JVM even if user thread is running. Run the below example by un comment DISPOSE_ON_CLOSE<\/code> in your IDE and you can see user thread running even after clicking on close button. Here is a complete code example of closing Swing application in Java.<\/p>\nimport java.util.logging.Level;\r\nimport java.util.logging.Logger;\r\nimport javax.swing.JFrame;\r\n\r\n\/**\r\n\u00a0* Java swing program which terminates itself by calling \u00a0EXIT_ON_CLOSE and DISPOSE_ON_CLOSE\r\n\u00a0*\/\r\npublic class CloseSwingExample {\r\n\r\n\u00a0 \u00a0 public static void main(String args[]) throws InterruptedException {\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 JFrame frame = new JFrame(\"Sample\");\r\n\u00a0 \u00a0 \u00a0 \u00a0 \/\/frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); won't terminate JVM if user thread running\r\n\u00a0 \u00a0 \u00a0 \u00a0 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);\r\n\u00a0 \u00a0 \u00a0 \u00a0 frame.setSize(200, 200);\r\n\u00a0 \u00a0 \u00a0 \u00a0 frame.setVisible(true);\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 Thread t = new Thread() {\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 @Override\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 public void run() {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 while (true) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 System.out.println(\"User thread is running\");\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 try {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Thread.sleep(100);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 } catch (InterruptedException ex) {\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 Logger.getLogger(CloseSwingExample.class.getName()).log(Level.SEVERE, null, ex);\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 }\r\n\u00a0 \u00a0 \u00a0 \u00a0 };\r\n\r\n\u00a0 \u00a0 \u00a0 \u00a0 t.start();\r\n\r\n\u00a0 \u00a0 }\r\n}\r\n\r\n<\/pre>\n3.3 Important Points for closing or terminating a Java application<\/h3>\n
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System.exit()<\/code> actually calls Runtime.getRuntime().exit()<\/code> method.<\/li>\nEXIT_ON_CLOSE<\/code> and other is DISPOSE_ON_CLOSE<\/code>.<\/li>\nDISPOSE_ON_CLOSE<\/code> doesn’t terminate JVM if any user thread is running.<\/li>\nSystem.exit()<\/code> in Swing application.<\/li>\n<\/ul>\nEXIT_ON_CLOSE<\/code> and DISPOSE_ON_CLOSE<\/code>.<\/p>\n4. Download The Source Code<\/h2>\n