classpath help

[jeffbroodwar]

Hi All,

I'm trying to run a sample program from this link:

http://java.about.com/od/tutorials/ss/SetClasspath.htm

it worked fine.. now the problem is... what if i do not want to use the set classpath command, instead, i just want to set the classpath in my system environment variable so that everytime i run the program, i'll just type javac file then java file. I tried to set this in the environment variable :

variable name: classpath
variable values: c:\javatest

but its not working... can anyone help me with this?

Thanks,
Pupoy

[JosAH]

Can you show us what you originally set using the -classpath flag? For the
environment version everything is similar: as a flag:

-classpath=foo

and as an environment variable:

set classpath=foo

kind regards,

Jos

[jeffbroodwar]

Hi Jos,


Thanks for the reply... i tried to type this in the command line :

STEP1 : set PATH = c:\program files\Java\jdk1.6.0_03\bin

STEP2 : javac C:\javatest\BarkingDogs.java

(Then specify where to find the class)

STEP3 : java -cp c:\javatest BarkingDogs

after completing these steps... i had a successful ran of the snippet...

Now, correct me if i'm wrong...is it correct that i can run the program by just typing :
* (for compiling)
javac BarkingDogs.java

* (for running program)
java BarkingDogs

meaning running the program by just doing steps 2 and 3(without cp word in step 3) since class path is already in environment variable.

Back to the original question... i just added under system environment variables :

variable name: classpath
variable value: ?

i'm using windows xp

Thanks,
Pupoy

[JosAH]

Your reasoning is all sound and solid but you have to pay special attention to
those path names with spaces in them. You need to use double quotes around
them otherwise MS Windows starts to be creative which you don't want.

kind regards,

Jos

[jeffbroodwar]

i dont get the spaces... u mean in the classpath values?

by the way, can you please give me a working class path for windows... just to accomplish the 2 steps i mentioned in my previous post:

javac BarkingDogs.java

java BarkingDogs

and... do i really always have to tell the windows where the java compiler is(Set path command) ? can't i just include it in the class path? separated by ;


Thanks,
Pupoy

[JosAH]

There are a few separate issues that have not much to do with each other:

The PATH variable
The PATH variable is a semi colon separated list of directories. The OS searches
those directories for executable files for which no explicit complete path was
given. java.exe and javac.exe are examples of executable files.

The CLASSPATH variable
The CLASSPATH variable is a semi colon separated list of directories and .jar
files. The JVM searches them for classes.

So you have to set your PATH variable to a suitable value if you just want to be
able to type 'java' or 'javac'. You have to set your CLASSPATH to the directories
where your .class files are stored and to the complete names of your .jar files.

If you want to be able to type 'javac MyClass.java' you have to change your
current working directory to where your MyClass.java file is stored.

btw. the space character I mentioned is present in the 'Program Files' directory
name. You have to take care of it by using double quotes. Check your manuals.

kind regards,

Jos

[jeffbroodwar]

Hi,

I know what executable files are... LOLZ.

btw, its just that i'm not really familiar on how to set the windows environment variable configuration. that's all. ROTFL...

thanks Jos, ^^ ;

Kind regards,
Pupoy

[JosAH]

Hi,

I know what executable files are... LOLZ.

btw, its just that i'm not really familiar on how to set the windows environment variable configuration. that's all. ROTFL...

thanks Jos, ^^ ;

Kind regards,
Pupoy

Check your Windows manuals for that issue, it has nothing to do with Java.

kind regards,

Jos

[jeffbroodwar]

I tried to create a new variable in the environment variables of windows...

variable : CLASSPATH
value : c:\javatest

still, i can't make it run in root directory :

c:\>javac BarkingDogs.java
c:\>java BarkingDogs

once classpath is defined in environment variable.... the system should already know the class location right? using java and javac keywords should trigger the variable classpath and tell the computer to get the value of the classpath variable...why is it still not working?

Thanks again,
Pupoy

[JosAH]

I tried to create a new variable in the environment variables of windows...

variable : CLASSPATH
value : c:\javatest

still, i can't make it run in root directory :

c:\>javac BarkingDogs.java
c:\>java BarkingDogs

once classpath is defined in environment variable.... the system should already know the class location right? using java and javac keywords should trigger the variable classpath and tell the computer to get the value of the classpath variable...why is it still not working?

Thanks again,
Pupoy

You can't compile a file BarkingDogs.java when your current working directory
is not the directory where that file is stored.

kind regards,

Jos

[jeffbroodwar]

hmm.... I tried to add classpath variable in the user variables (the one at the top)
, it worked for running the class file. but when i try to compile .java files... it can't locate the directory of classpath.

c:\>javac BarkingDogs.java = (Doesn't work)

(lets say the directory contains class files)

c:\>java BarkingDogs = (successful !)

here's my classpath variable :

variable : classpath
variable value : .;c:\javatest


It seems that the system can now see the classpath variable when using java command. but if i'll try to use javac command.... hmm... not working?! that's weired ! (FYI : i already added in system variable the path of java compiler
i.e. c:\program files\Java\jdk1.6.0_03\bin

Thanks again,
Pupoy

[jeffbroodwar]

just received your reply jos. thanks. so it's not possible to use javac command in any directory even if you've set the classpath variable. only java command to execute the file will work. now i understand. thanks man.

Thread closed.

Thanks,
Pupoy