Doubt in classpath statement....

[sunil langeh]

 
Given the default classpath:
/foo
And this directory structure:
foo
|
test
|
xcom
|--A.class
|--B.java
And these two files:
package xcom;
public class A { }
package xcom;
public class B extends A { }
Which allows B.java to compile? (Choose all that apply.)
A. Set the current directory to xcom then invoke
javac B.java
B. Set the current directory to xcom then invoke
javac -classpath . B.java
C. Set the current directory to test then invoke
javac -classpath . xcom/B.java
D. Set the current directory to test then invoke
javac -classpath xcom B.java
E. Set the current directory to test then invoke
javac -classpath xcom:. B.java
   

Ans. is C
Why not others like B, E? (Got from - K&B)

[Balu Sadhasivam]

Sunil.

The top level of package should be directly under classpath . ( thats wat I would always prefer) , so test directory must be in classpath to get the copilation successful as xcom is where package starts.


B and E does not include test directory in classpath !!

[sunil langeh]

Balu Sadhasivam wrote:Sunil.

The top level of package should be directly under classpath . ( thats wat I would always prefer) , so test directory must be in classpath to get the copilation successful as xcom is where package starts.


B and E does not include test directory in classpath !!

Thanks Balu for quick reply, but it still not completely clear to me, Would you please elaborate it???

[Balu Sadhasivam]

OK. For B.java to compile , test directory must be in classpath , wuld you agree to this atleast ? ( which means you agree that C is correct )

[sunil langeh]

Balu Sadhasivam wrote:
OK. For B.java to compile , test directory must be in classpath , wuld you agree to this atleast ? ( which means you agree that C is correct )

Yes, but what about E
E. Set the current directory to test then invoke
javac -classpath xcom:. B.java

[Balu Sadhasivam]

because B.java is not in the test directory. Classpath is where JVM searches for class files and not java files.

So javac -classpath xcom:. B.java , would search for B.java in current directory which is test

P.s : Wish my Broadband connection is as stable as Java

[Jesper de Jong]

This question has been asked and discussed before in the SCJP forum:

http://www.coderanch.com/t/427256/Programmer-Certification-SCJP/certification/Classpath
http://www.coderanch.com/t/426637/Programmer-Certification-SCJP/certification/Class-path-again
http://www.coderanch.com/t/426283/Programmer-Certification-SCJP/certification/Classpath-setting-involving-java-javac
http://www.coderanch.com/forums/posts/list/40/426145

Please search the forums for "xcom", and you'll find more.