How can I run a jar file?

Question

I searched long to find code to run a jar file, but this is the only code I found:

public class Main {
    
    public static void main (String args[]) {
        try {
            Runtime.getRuntime().exec("java -jar C:/Users/lordb/Desktop/Server/NewBuildTest/spigot-1.18.1.jar");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

but it didn't work. Just nothing happens. No Exception, no Error, nothing. Can someone help me?

Answer 1

There is at least one cause, because there is no single command with the name

"java -jar C:/Users/lordb/Desktop/Server/NewBuildTest/spigot-1.18.1.jar"

What you want, is to execte the command "java" with the 2 arguments "-jar" and "C:/Users/lordb/Desktop/Server/NewBuildTest/spigot-1.18.1.jar". You can do that by passing the command and its arguments via String array. In your case that would be an array of 3 Strings.

Javadoc: https://docs.oracle.com/javase/7/docs/api/java/lang/Runtime.html#exec(java.lang.String[])

In that javadoc you can see that exec returns a new Process object. Such Process provides more information, eg the exit code of your process (via waitFor ) and access to (error) output messages (via getInputStream ).

Javadoc: https://docs.oracle.com/javase/7/docs/api/java/lang/Process.html

Example: Printing a Java InputStream from a Process

Note: You didn't specify which Java version you are using, so i just picked a "random" version for the javadoc links. You might need to look for the version you are using.