"Error: Main Method Not Found in Class Myclass, Please Define the Main Method As..."

Error: Main method not found in class MyClass, please define the main method as...

When you use the java command to run a Java application from the command line, e.g.,

java some.AppName arg1 arg2 ...

the command loads the class that you nominated and then looks for the entry point method called main. More specifically, it is looking for a method that is declared as follows:

package some;
public class AppName {
    ...
    public static void main(final String[] args) {
        // body of main method follows
        ...
    }
}

The specific requirements for the entry point method are:

1. The method must be in the nominated class.
2. The name of the method must be "main" with exactly that capitalization¹.
3. The method must be public.
4. The method must be static ².
5. The method's return type must be void.
6. The method must have exactly one argument and argument's type must be String[] ³.

(The argument may be declared using varargs syntax; e.g. String... args. See this question for more information. The String[] argument is used to pass the arguments from the command line, and is required even if your application takes no command-line arguments.)

If anyone of the above requirements is not satisfied, the java command will fail with some variant of the message:

Error: Main method not found in class MyClass, please define the main method as:
   public static void main(String[] args)
or a JavaFX application class must extend javafx.application.Application

Or, if you are running an extremely old version of Java:

java.lang.NoSuchMethodError: main
Exception in thread "main"

If you encounter this error, check that you have a main method and that it satisfies all of the six requirements listed above.

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<sup>1 - One really obscure variation of this is when one or more of the characters in "main" is NOT a LATIN-1 character … but a Unicode character that looks like the corresponding LATIN-1 character when displayed.

2 - Here is an explanation of why the method is required to be static.

3 - String must be the standard java.lang.String class and not to a custom class named String that is hiding the standard class.</sup>

Error :: Main method not found in class

To start a java program you need the main method which not define in your code you can make it like this :

public class Test {

    public void printPhoto(int width, int height, boolean inColor) {
        System.out.println("Width = " + width + " cm");
        System.out.println("Height = " + height + " cm");
        if (inColor) {
            System.out.println("Print is Full color.");
        } else {
            System.out.println("Print is black and white.");
        }
        // printPhoto(10, 20, false); // Avoid a Stack Overflow due the recursive call
    }

    //main class
    public static void main(String[] args) {
        Test tst = new Test();//create a new instance of your class
        tst.printPhoto(0, 0, true);//call your method with some values        
    }

}

Main method not found even if I've declared it

As said in my comments, looks like you've declared a String class among your own classes. To prove this, I've created a basic example:

class String {
}

public class CarelessMain {
    public static void main(String[] args) {
        System.out.println("won't get printed");
    }
    public static void main(java.lang.String[] args) {
        System.out.println("worked");
    }
}

If you execute this code, it will print "worked" in the console. If you comment the second main method, the application will throw an error with this message (similar for your environment):

Error: Main method not found in class edu.home.poc.component.CarelessMain, please define the main method as:

public static void main(String[] args)

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