NoClassDefFoundError exception

[pingkan paula]

Hi all,

I'm running a java program from command prompt, it has passed compilation and when i run i found this exceptions :
C:\Java-source>java Template.java
Exception in thread "main" java.lang.NoClassDefFoundError: Template/java
I have the main.class in the directory, so how come it throws java.lang.NoClassDefFoundError?
Please give me any feedbacks
However, this is my source code

  
import java.io.*;
import java.util.*;
 
class Main 
{
Main(){
}
static String ReadLn(int maxLg){
byte lin[]=new byte[maxLg];
int lg=0, car=-1;
String line="";
 
try{
while(lg<maxLg){
car=System.in.read();
if((car<0)||(car=='\n'))break;
lin[lg++]+=car;
}
}catch(IOException e){
return (null);
}
if((car<0)&&(lg==0)) return (null);
return (new String(lin,0,lg));
}
 
public static void main(String[] args) 
{
Main myWork=new Main();
myWork.Begin();
}
 
void Begin(){
String input=null;
StringTokenizer idata;
int a,b,min,max,num,n,cycle,cyclemax;
while((input==Main.ReadLn(255))){
idata=new StringTokenizer(input);
a=Integer.parseInt(idata.nextToken());
b=Integer.parseInt(idata.nextToken());
if(a<b){min=a;max=b;}else{min=b;max=a;}
for(cyclemax=-1,num=min;num<=max;num++){
for(n=num,cycle=1;n!=1;cycle++)if((n%2)!=0)n=3*n+1;else n>>=1;
if(cycle>cyclemax)cyclemax=cycle;
 
}
System.out.println(a+" "+b+" "+cyclemax);
}
}
}
 
  

[bhuvan sundar]

Posted by Pingkan
C:\Java-source>java Template.java

just give java Template

[pingkan paula]

Still give the same exception...

[Prabhu Venkatachalam]

set classpath to the current working directory.

set CLASSPATH=.; ==> "." represents current working directory.

now, try C:\Java-source>java Template

[Jesper de Jong]

Your class is called "Main", so where does the name "Template" come from?

If your class is called "Main", it should be in a source file called "Main.java". After compiling it, you should run it with:

java -cp . Main

[Abdul Rehman]

Originally posted by Jesper Young:
If your class is called "Main", it should be in a source file called "Main.java".

This is not a restriction as the class "Main" in your code is NOT a public class. Had it been a public class, it would have been compulsory to do so. However, I also prefer that you should name your file "Main.java", but, it isn't necessary (unless you declare it public.)

Regards,
Abdul Rehman.

[Ernest Friedman-Hill]

If your class isn't public, then recent JDKs will refuse to execute it if it's in a named package. You need to make it public.

Also, don't be setting the classpath; it often just makes things worse down the road. Instead use

java -cp . Template.Main

That's "java space dash cp space Template dot Main" .

[Abdul Rehman]

Is this behaviour also shown by JDK 1.5? What if I get a question in the SCJP 5 exam or any mock exam about this?