command line arguments

[jttslg]

how to use the commandline argument
i get the following error:
c:\users\jtt\documents> java Echo one two three
Exception in thread "main" java.lang.NoClassDefFoundError: Echo
Caused by :java.lang.ClassNotFoundException: Echo
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPriviledged(Nativ e Method)
at java.net.URLClassLoader.findClass(Unknown Source)........
Could not find the main class: Echo. Program will exit.

Please help

[j2me64]

is Echo.java compiled with javac without errors? looking at the erros i don't believe. so post your Echo.java code here.

[jttslg]

yes echo.java is compiled ...
public class Echo
{
public static void main(String args[])
{
for (int i=0;i<args.length;i++)
System.out.println("args[" + i + "]: "+args[i]);
}
}

[pbrockway2]

Go to the directory (folder) containing Echo.class and run the program with the following command:

java -cp . Echo

The "-cp" tells the java executable where to look for classes. And the dot means "here, in this directory".

[nigamsir]

1. install jdk
2. install netbeans
3. set command line arguments from project properties

[The_Sponzy_Paradox]

I think the problem is that your echo class is in a different directory. Move echo into the same place as your main and then recompile both of them. After that it should run.

[jttslg]

i tried the given suggestions but the error remains the same.... i am using jdk1.6.0_17

[jttslg]

it is however running in bluej but i wanted to try it in the command.exe while using the notepad as the editor.. my os is windows 7

[Eranga]

Are you sure that you've set the class path properly?

[The_Sponzy_Paradox]

Is the class named echo not echo one two three? Then try making the class name echo1 or something like that resave and recompile with the new class name

[Eranga]

Is the class named echo not echo one two three? Then try making the class name echo1 or something like that resave and recompile with the new class name

No, file may save as echo.java, not Echo.java and the parameters have nothing to do with that. As I said earlier it couldn't be relate to classpath.

[jttslg]

how do i know that classpath is the problem. it is compiling all right. when i give the arguments it shows the errors

[The_Sponzy_Paradox]

c:\users\jtt\documents> java Echo one two three
Exception in thread "main" java.lang.NoClassDefFoundError: Echo
Caused by :java.lang.ClassNotFoundException: Echo

How to tell is you read the error. An exception is a problem a program cannot answer. Thus we have there is a problem in the main thread, java.lang.NoClassDefFoundError: Echo is just that there is a problem with the class Echo

[The_Sponzy_Paradox]

No, file may save as echo.java, not Echo.java and the parameters have nothing to do with that. As I said earlier it couldn't be relate to classpath.

Perhaps but you can never be completely certain till you try. Retype everything in a new file generated in notepad. recompile and try again. I have encountered similar problems in school and that was the fix to most of them. And exceptions rarely lie

[pbrockway2]

Perhaps but you can never be completely certain till you try. Retype everything in a new file generated in notepad. recompile and try again. I have encountered similar problems in school and that was the fix to most of them. And exceptions rarely lie

Actually you can be completely certain that there is no problem with the classpath by using the approach I suggested in #4. (which is why I suggested that approach.)

The OP's response: "i tried the given suggestions but the error remains the same.." is unconvincing without a cut/paste and post from the command line. It would be good to include the output from the "dir" command as well so that we can verify that the precondition of #4 is met. (ie that the command is issued from the directory containing the file Echo.class)

[Eranga]

Perhaps but you can never be completely certain till you try. Retype everything in a new file generated in notepad. recompile and try again. I have encountered similar problems in school and that was the fix to most of them. And exceptions rarely lie

I don't think recoding is not a good solution, actually not a good practice. If it's a huge Java class, then you are going to retype them? How the errors can be avoid/tackle by retyping the code.

And as far as I feel, Java exceptions not pointed incorrect stuff. If you comes with an exception (compile/run-time) definitely there is an error in the code.

[The_Sponzy_Paradox]

Yeah, we would cut/copy as needed usually did the trick till the networking people fixed eclipse. Just an idea, I always did fine on my personal projects with either textpad or emacs and konsol shell.

[Eranga]

Unless it's fix the problem somehow it's fine. But that couldn't be because of the copy-paste. There is no magic in coding in any language.

[jttslg]

can there be an error in the coding when it is working correctly on blue but not in the command.exe

[jttslg]

on blue j environment