Windows runs java projects (programs) with the command line

Due to the need to run the java project on the command line. First of all, there must be jdk on the computer, which is a necessary condition. Secondly, you can create a new project folder, such as ShowTime, and then create a new src folder (just for convenient management, not necessarily necessary), then you can create a new java file in it.

import java.util.*;

public class HelloDate{
    public static void main(String[] args){
        System.out.println("Hello,it's:");
        System.out.println(new Date());
    }
}

In this way, name it time.java

and then operate on the command line, first enter the src folder, and then type:

javac time.java

At this time, an error is reported, because the file name is inconsistent with the class name, so change the file name to HelloDate.java, and type again:

javac HelloDate.java

At this time, no error is reported, indicating that the compilation is successful!
Then according to many blog tutorials on the Internet, type the following command:

java HelloDate.class

It was wrong... So I changed it to another way of writing, and it's still the same.

Finally found a solution online:

java -cp ./ HelloDate

Finally it worked!
As for compiling multiple java files, use the following command:

javac *.java

It's ok, you must choose a class with a main method to run when running!