找不到或加载主类Java错误记事本++

Question

I've implemented "Java Compile" and "Compile and Run" (the second as Java Compile and Run) as described in this answer: Java compile and run using notepad++ and nppexec .

Note: I'm using 1.8.0_20 rather than 1.7.0 as described in the answer.

However, when I try to run HelloWorld (as found here: http://docs.oracle.com/javase/8/javafx/get-started-tutorial/hello_world.htm ) to test the compiler, I get the following response, including a "Could not find or load main class" error:

NPP_EXEC: "Java Compile and Run"
CD: C:\Users\Bova\Documents
Current directory: C:\Users\Bova\Documents
"C:\Program Files (x86)\Java\jdk1.8.0_20\bin\java" -classpath "C:\Users\Bova\Documents"    "HelloWorld"
Process started >>>
Error: Could not find or load main class HelloWorld
<<< Process finished. (Exit code 1)
================ READY ================

What do I need to change to avoid this error?

Answer 1

The very first line of HelloWorld.java reads:

package helloworld;

Java packages are mapped to directories on the filesystem, so the interpreter expects to find HelloWorld.class inside a helloworld directory. Move the .class file to a helloworld subdir and run it as:

> java helloworld.HelloWorld

from the parent directory (ie the directory which contains helloworld/ ).

Answer 2

I had this problem in Notepad++ too. What I did to fix it was I went to the Plugins menu, clicked on NppExec, and selected Follow $(CURRENT_DIRECTORY) . After that I can run programs just fine.