Question

I’m trying to implement the following:

 public class Main {
     public static void main(String[] args) {
    //READ FILE IN
         String filename = args[0];
         System.out.println(filename);
      }}

This compiles fine, but when I try to run java br/com/seimos/minijava/Main.java < a or java br/com/seimos/minijava/Main.java a for example, I get an error. Why?? (by the way, I need to get it so that I can do java br/xx/xx.../xx.

Thanks!

EDIT: Sorry, I typed it wrong initially. I DID run java not javac.

The error I get is:

Exception in thread "main" java.lang.NoClassDefFoundError: br/com/seimos/minijava/Main/java
Caused by: java.lang.ClassNotFoundException: br.com.seimos.minijava.Main.java
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)

Answer 1

You don’t pass arguments at compile-time, but at runtime.

javac --> compiles your Java program
java --> runs the generated bytecode

---

java br/com/seimos/minijava/Main.java -args
                                   ^ remove (.java)

Java runtime runs the .class bytecode-generated, which is of the name supplied, not the uncompiled .java source