Develop Reference

How to launch program in psvm?

How to launch a program in psvm with one command?
How does the application know which class to launch first?
I know that psvm should only have starting command and nothing more.
Could you explain this to me?
I mean how to create proper public static void main(String[] args) in a simple program on Maven. Should I create a class i.e. Starter with method run (with sequence actions) and in psvm write new Starter().run()?

psvm stands for public static void main as shown below:
public static void main(String[] args) {
// Your code here
}
psvm is not a standard Java terminology. You can call it as a Java slang. It is the entry point in your standalone Java application i.e. when you run an executable jar, it will execute the class having psvm. There are so much of content about it on the internet e.g. https://dzone.com/articles/executable-java-applications

The main() is the first entry point of Java application. Java Virtual Machine is told to run an application by specifying its class using the application launcher & it will look for the main() with exact syntax of public static void main(String[]).

Considering your comments you want to do something like this :
public class Starter{
public static void main(String args) {
new Starter().run();
}
public void run() {
//your logic
}
}
once you write this,
you have multiple options to run this I am mentioning a few
1) by building jar and then executing that jar using java -jar command
2) or by executing maven command once you have compiled your program using mvn compile, mvn exec:java -Dexec.mainClass="complete name of your main class i.e including package name."
a few links
http://www.vineetmanohar.com/2009/11/3-ways-to-run-java-main-from-maven/
https://www.oracle.com/webfolder/technetwork/tutorials/obe/java/Maven_SE/Maven.html
hope this might help

Cannot Run Class Files

Notice that the run option for the main class is greyed out. I tried restarting intelliJ, rebuilding, cleaning, everything.
(click to zoom in)

Move your code inside of the src folder. Once it's there, it'll be compiled on-the-fly every time it's saved.
IntelliJ only recognizes files in specific locations as part of the project - namely, anything inside of a blue folder is specifically considered to be source code.
Also - while I can't see all of your source code - be sure that it's proper Java syntax, with a class declared the same as the file and that it has a main method (specifically public static void main(String[] args)). IntelliJ won't run code without a main method (rather, it can't - neither it nor Java would know where to start).
Use
public static void main(String[] args))

Your main method requires a String array or varargs argument to be picked up.

Correct your main() method, from:
public static void main() {...}
to
public static void main(String[] args) {...}

Java - can't run program in Eclipse

I can't run HelloWorld in Eclipse - it shows message:
Error: Main method not found in class com.taksila.javabyexample.overview.HelloWorld, please define the main method as:
public static void main(String[] args)
or a JavaFX application class must extend javafx.application.Application
Here is my code:
package com.taksila.javabyexample.overview;
public class HelloWorld {
public static void main(String[] args){
System.out.println("Hi Planet");
}
}

Code is correct. Try to restart IDE or just save sketch :-)

Yes, your code is definitely correct. Save it, restart the IDE, and wait to load all of its components. Then again run it!

Eclipse run configuration

When i'm trying to run in Eclipse program which has no main method as Java Application it always requires a main method to define. Could anybody please explain is there any simpler way to make configuration run without implementing
public static void main(String[] args) {
}

Every program requires a main method.
The public static void main(String args[]) starts the main thread which your program will run on.
There's more information available here.

You need a main method to run your program.
public static void main(String[] args){
YourClass newObject = new YourClass();
}
Put this method in your class (replace YourClass with your existing class) and hit the run button.

run in Eclipse program which has no main method
NO.You won't be able to run a class by using IDE like Eclipse or anything else. Even you won't be able to run your java program by using Java command from your command prompt, until your java program has public static void main(String args[]) method on it. If you try to run, you will get below mentioned error
Error: Main method not found in class Test, please define the main
method as: public static void main(String[] args)
But you should also know that, we can run a Java program without main method on managed environment like the case of Applet, Servlet and MIDlet. There are actually different types of execution model available in Java, for example Applets which run on browser doesn't have main method. Servlet is also java program, which runs in a Servlet container and since Servlet is also a Java program, we can say that it runs without main method. Third one on this category is MIDlet, which runs on mobile devices.

Eclipse "Run as" has no "Java Application" option (What exactly is needed to be able to run a class/.java?)

I want to run a specific .java file (a class), but Eclipse is not co-operating.
I have tried to follow the instructions here -->
eclipse how to run a different class
... but my "Run As" menu item never contains "Java Project".
I have tried accessing the menu after right-clicking in the .java pane and tab itself, and from the .java name and class name in the Package Explorer, but of course that doesn't make a difference. The only option I ever get is "Run Configurations".
(and yes, my .java has a "main" method.)
import com.jsyn.JSyn;
public class SuperSimpleSounds {
public static void main() {
[...]
What, exactly, is needed to be able to run an individual class (an individual .java file)?

Add a String array argument to the main method as expected by the JVM
public static void main(String[] args) {

Also one trick when you want to open some java classes that you downloaded elsewhere is to create a new Java project. Then, move all your java classes into the src folder of the project. Now you can run with the option of "run as Java Application".

As a minor variation on the perfect answer of Reimus:
Add a String array argument to the main method as expected by the JVM
public static void main(String[] args) {
I had been struggling with my a script, when I ran it showed Run Configuration and Fail.
By changing the following:
public static void LaunchBrowser () throws InterruptedException {
to
public static void main(String[] args) throws InterruptedException {
it solved the problem.