"Error: could not find or load the main class My.class"

Question

Im using Java SDK 1.7 for Windows 7 via cmd.exe. Until a few hours ago everything worked correctly, all of a sudden I was not able to run my compiled class files, consistently presented with an error in the header.

It seems I can compile my My.java file, but I cannot run the resulting class file (My.class). I constantly get the error "Error: Could not find or load the main class My.class". I tried this with several other class files, all this leads to the same problem.

The environment variable "Path" is set to "C: \ Program Files (x86) \ Java \ jdk1.7.0_05 \ bin" if you are interested

I tried reinstalling, creating and setting the classpath variable (no luck) and even using directly

java -cp . My.class

teams.

I tried these posts all to no avail, so why am I posting:

Error: could not find or load the main class

Error: could not find or load the main class - newbie

Could not find or load main class

Java 1.7.0_03 Error: could not find or load the main class

If that matters, my code is:

 import javax.swing.JOptionPane; class My { public static void main(String[] args) { final double x = 3.2; int i = (int)x; double m = 0; if (x < 4) { String saySomething = JOptionPane.showInputDialog(i); System.out.println(saySomething); } else { String saySomething = JOptionPane.showInputDialog(i); System.out.println("Hello World"); } while (m < 10) { System.out.print(" While Loop "); m++; }; for (i=1; i < 10; i++) { System.out.println("For Loop"); }; } } 

Answer 1

You must specify the class name instead of the loadable class file. The difference lies in the simple removal of the .class extension.

Answer 2

I would use an IDE and you should not get these problems. Compiling and running is just a click away.

BTW to run your program from the command line

 java -cp . My 

You do not add .class

Answer 3

Put yourself in the directory of your project (you need to have the src and bin directories, assuming you keep the sources in src and binaries in the trash)

 java -cp bin My 

Answer 4

I myself faced the same problem. This happened because I was mistaken in typing the class name correctly. In my case, I typed

java doubler

instead

java doubler