How to Launch a Application or Executable Using Java Code with Command Line Arguments

In this post, we shall see how to launch an application with its command line arguments using Java code. Most applications take path of a file as command-line argument to open it. If we give path of an image file to mspaint application as command-line argument, the image will be opened in paint. The following java program launches mspaint with a command-line argument which is a path to an image.

 try
 {
 Runtime.getRuntime().exec("C:\\Windows\\System32\\mspaint.exe \"C:\\Users\\Shareef\\Desktop\\flower.jpg\"");
 } catch (IOException ex) {}

Arguments are separated by spaces. If a command-line argument contains space within it (such as a space in a path), it is recommended to enclose it within brackets.

How to Load a Webpage in a Java App

Do you wonder how to load a webpage in your java application? It is simple. You can load a web document whether it is a web document in internet or a web document from a file in the localhost. I know three methods to do it. You can use JTextPane in java swing (javax.swing), JEditorPane in java swing (javax.swing) or WebView in javaFX (javafx.scene.web.WebView). We will discuss each method to display a webpage in a java application.

The three methods we are going to discuss are:

• Using JTextPane
• Using JEditorPane
• Using WebView in JavaFX

How to Set JFrame in Center of Screen

By default, a java application appears at top left corner of the screen. You might have seen that most of the applications appear in the middle of the screen. I will tell you how to center your java application on screen.

To set JFrame in center of Just call this.setLocationRelativeTo(null); in constructor of the JFrame. If you are using Netbeans IDE, it should be after calling initComponents() method. But if you call setLocation() method of JFrame after this, your JFrame will get relocated.

In most cases this works and this is enough. if you want to get the center point of the screen, just refer to the following post:

How to Get Center Point of Screen in Java

How to Close or Exit a Java App When some Button is Clicked

To close a Java app, System.exit() can be used. This function can be used to close the app if an error occurs or no error is occurred. If no, error occurred, the argument  of the function should be 0. This method terminates the currently running Java Virtual Machine. The argument stands for status code; by convention, a nonzero status code indicates abnormal termination. If you are calling the System.exit() function without any errors (in normal case), just give the argument as zero. This method calls the exit method in class Runtime.