filenames on the command line

[giuseppe.on.usenet]

The current directory has two files:

/* A.java */
package wrk.pkg;
import wrk.B;
class A { B b; }

/* B.java */
package wrk;
public class B { }

The command javac -d . A.java B.java
compiles successfully, while javac -d . A.java
halts because it "cannot find symbol: class B". My question is: by
adding other options, is it possible to have the compiler seek and
compile B.java without specifying the filename on the command line?

 

[Lew]

The current directory has two files:

That's your first mistake - using the current directory.

/* A.java */
package wrk.pkg;

This needs to be in directory "wrk/pkg/" relative to one of the classpath roots.

I.e., the current directory the way you're working.

import wrk.B;
class A { B b; }

/* B.java */
package wrk;

This needs to be in relative directory "wrk/".

Notice that this is necessarily a *different* directory than the other class.

public class B { }

The command javac -d . A.java B.java

You're supposed to use directory notation with javac rather than "dot" notation.

I was not aware that dot notation even worked here.

In any case, it only partially "worked", not completely, at best, because you have things in the wrong directories.

compiles successfully, while javac -d . A.java
halts because it "cannot find symbol: class B". My question is: by

Because things are in the wrong directories.

adding other options, is it possible to have the compiler seek and
compile B.java without specifying the filename on the command line?

Why don't you read the documentation?

You will find it astonishingly helpful.

 

[giuseppe.on.usenet]

That's your first mistake - using the current directory.

I am studying for an Oracle certification and I found this exercise in
a book. There are at least five similar questions and all of them put
the classes in the same directory, even if they belong to different
packages. I agree with you that this is not the best practice but it
is not my fault if the quiz is conceived that way.

[...]
Why don't you read the documentation?

You will find it astonishingly helpful.

Three books + the man page should be enough but if I had found the
answer there I wouldn't have posted here.

 

[Lew]

I am studying for an Oracle certification and I found this exercise in
a book. There are at least five similar questions and all of them put
the classes in the same directory, even if they belong to different
packages. I agree with you that this is not the best practice but it
is not my fault if the quiz is conceived that way.

It's not "not a best practice", it's the wrong way to do it.

It is your fault if you fail to learn the truth of what Java does.

[...]
Why don't you read the documentation?

You will find it astonishingly helpful.

Three books + the man page should be enough but if I had found the
answer there I wouldn't have posted here.

Oracle's Java site has the best fundamental data and generally easiest to get to, plus it's authoritative. Everyone should have bookmarks to the tools documentation
http://docs.oracle.com/javase/7/docs/
(or use http://lmgtfy.com/?q=java+tools+documentation)
specifically
http://docs.oracle.com/javase/7/docs/technotes/tools/index.html#basic
"You should arrange source files in a directory tree that reflects their package tree. For example, if you keep all your source files in /workspace, the source code for com.mysoft.mypack.MyClass should be in /workspace/com/mysoft/mypack/MyClass.java."

The tutorials give the same information.

 

[Roedy Green]

he command javac -d . A.java B.java
compiles successfully, while javac -d . A.java
halts because it "cannot find symbol: class B". My question is: by
adding other options, is it possible to have the compiler seek and
compile B.java without specifying the filename on the command line?

javac *.java

It won't recompile if not necessary.

If you want fast compiles you need ANT , if you have several packages
to compile.

see http://mindprod.com/jgloss/ant.html
--
Roedy Green Canadian Mind Products
http://mindprod.com
For me, the appeal of computer programming is that
even though I am quite a klutz,
I can still produce something, in a sense
perfect, because the computer gives me as many
chances as I please to get it right.

 

[Roedy Green]

This needs to be in directory "wrk/pkg/" relative to one of the classpath roots.

This drives every newbie nuts. I discovered that thinking about HOW
the compiler finds java source and how java.exe finds classes made it
all fall into place.

see
http://mindprod.com/jgloss/helloworld.html
http://mindprod.com/jgloss/classpath.html
http://mindprod.com/jgloss/package.html
http://mindprod.com/jgloss/javacexe.html
http://mindprod.com/jgloss/javaexe.html

--
Roedy Green Canadian Mind Products
http://mindprod.com
For me, the appeal of computer programming is that
even though I am quite a klutz,
I can still produce something, in a sense
perfect, because the computer gives me as many
chances as I please to get it right.