Pass parameters to jar file

Question

I have an example project ready (very simple), however I would like to make a connection configurator with the database. Once compiled, the system creates a.jar file and I would like to know how to pass a parameter in the executable to call the database configurator (Ex: .jar file /db).

Answer 1

If the goal is to pass parameters to the jar, just treat the Strings array that method main of the main class receives, because it is through it that external commands are passed the execution of the jar in the virtual machine.

To illustrate, I have elaborated the following example:

import javax.swing.JOptionPane;

public class MainTeste {

    public static void main(String[] args) {


        String commands = "";

        for(String str : args) {
            commands += str;
        }

        JOptionPane.showMessageDialog(null, "Foram passados os seguintes comandos: " + commands);

    }

}

Note that I am scanning the array received by the main and concatenating a variable to the part, and then displaying. After generating a .jar, just pass the parameters through a command line similar to below:

java -jar seuJarFile.jar comando1 comando2 comando3

See the code above, after generating the jar, working:

It is worth noting that the parameters should be separated by space, if you have some parameter that contains space (such as file names or paths, for example), it should be passed between double quotes.

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Related Topics:

• What public Static void main(String[] args means)?
• Why it is mandatory to implement "public Static void main (String [] args)"?

Answer 2

Following your tip, I got with the code below.

public static void main(String[] args) {

    String commands = "";

    for(String str : args) {
        commands += str;
    }

    if (commands.equals("db")) {
        TelaConfigDB.main(null);
    } else {
        TelaSplash.main(null);
    }
}