Question

My program consists of classes that extend other classes. The problem is, when I try to compile them in cmd, system says “Cannot find symbol”. Some sites discussing similar problems mention including the source folder in the CLASSPATH. I did as they said and it still gives the same error. However, it runs smoothly in Eclipse. Any ideas why?

Answer 1

Make sure that you compile the top level class first. If you try to compile a class extending other class, and you don’t have compiled .class file for that class, you will get that error.

package pkg1;
class A { }

package pkg2;
import pkg1.A;
class B extends A { }

For the above code, you should compile the .java file containing your class A first to get your .java file containing class B compiled. Also, set the path containing your class files in your classpath.

In Eclipse, it works because it automatically compiles your classes as you save them.

NOTE: –

If you are having your classes under some packages, then compile your java files using this command: – javac -d . A.java. This will create a folder for the package name and put the class file in that folder automatically. Then your class B would be able to find it