interface

[deepak prashad]

file name askme.java; saving this file in the bin folder.

import java.util.Random;

interface SharedConstants {
  int NO = 0;
  int YES = 1;
  int MAYBE = 2;
  int LATER = 3;
  int SOON = 4;
  int NEVER = 5;
}

class Question implements SharedConstants {
  Random rand = new Random();
  int ask() {
    int prob = (int) (100 * rand.nextDouble());
    if (prob < 30)
      return NO;           
    else if (prob < 60)
      return YES;          
    else if (prob < 75)
      return LATER;        
    else if (prob < 98)
      return SOON;         
    else
      return NEVER;        
  }
}

class AskMe implements SharedConstants {
  static void answer(int result) {
    switch(result) {
      case NO:
        System.out.println("No");
        break;
      case YES:
        System.out.println("Yes");
        break;
      case MAYBE:
        System.out.println("Maybe");
        break;
      case LATER:
        System.out.println("Later");
        break;
      case SOON:
        System.out.println("Soon");
        break;
      case NEVER:
        System.out.println("Never");
        break;
    }
  }

  public static void main(String args[]) {
    Question q = new Question();
    answer(q.ask());
    answer(q.ask());
    answer(q.ask());
    answer(q.ask());
  }
}

compiling using c:\java\jdk1.6.0\bin> javac askme.java compiled successfully ;
run using c:\java\jdk1.6.0\bin> java AskMe
error-
exception in thread "main" java.lang.noclassdeffounderror: AskMe;

how to solve this suggest me thankyou

[William P O'Sullivan]

Case Sensitive!

askme is NOT the same as AskMe

Pat.

[Seetharaman Venkatasamy]

javac askme.java compiled successfully

[Seetharaman Venkatasamy]

Plus, Constant Interface is an Anti pattern-why? search here...remember many times discussed here...

[Bear Bibeault]

Is this for a school assignment where you must do things this way? If not, you should be using enums rather than constants.

[deepak prashad]

i know case sensitive also when compiling c:\java\jdk1.6.0\bin> javac AskMe.java no problem during compilation.
but at run time c:\java\jdk1.6.0\bin> java AskMe
error-
exception in thread "main" java .lang.noclassdeffounderror;

arises even with all programing when i am compiling no error but at run time same error mention above while i run same class before it run successfully;

[William P O'Sullivan]

Is CLASSPATH environment variable set?

do a dir, are you sure the AskMe.class exists?

Why are you putting source in the Java bin (system folder)?

These classes are in one file?

Split them out into AskMe,java, SharedConstants.java and Question.java. Compile each one and ensure .class files exist.

This is what I get from a command line, running a small Java app.

c:\Users\osullivanw\workspace\wposStuff\bin>java RunMeForSql
letter: f count:1
letter: g count:1
letter:   count:7
letter: d count:1
letter: e count:2
letter: n count:1
letter: o count:2
letter: l count:1
letter: h count:2
letter: i count:4
letter: w count:1
letter: T count:1
letter: u count:2
letter: t count:1
letter: s count:2
letter: r count:1

Which works, no CLASSPATH, nothing.

c:\Users\osullivanw\workspace\wposStuff\bin>dir RunMe*
Volume in drive C has no label.
Volume Serial Number is 30B6-DDBB

Directory of c:\Users\osullivanw\workspace\wposStuff\bin

04/03/2012 02:23 PM 8,167 RunMeForSql.class
1 File(s) 8,167 bytes
0 Dir(s) 247,761,305,600 bytes free

Pat.

[deepak prashad]

file name Example.java and saving this file in bin folder.
class Example {
// Your program begins with a call to main().
public static void main(String args[]) {
System.out.println("This is a simple Java program.");
}
}
c:\java\jdk1.6.0\bin> javac Example.java; no error
c:\java\jdk1.6.0\bin> java Example;
error-
eeception in thread "main" java.lang.noclassdeffounderror: Example;

[Seetharaman Venkatasamy]

any package to your class?

[William P O'Sullivan]

c:\Users\osullivanw\workspace\wposStuff\bin>java AskMe
No
Soon
No
No

c:\Users\osullivanw\workspace\wposStuff\bin>dir *.class
Volume in drive C has no label.
Volume Serial Number is 30B6-DDBB

Directory of c:\Users\osullivanw\workspace\wposStuff\bin

04/03/2012 03:05 PM 974 AskMe.class
04/03/2012 03:05 PM 605 Question.class
04/03/2012 03:05 PM 299 SharedConstants.class
21 File(s) 53,623 bytes
0 Dir(s) 247,760,510,976 bytes free

c:\Users\osullivanw\workspace\wposStuff\bin>

Even with one file AskMe.java, it runs fine:

c:\Users\osullivanw\workspace\wposStuff\bin>java AskMe
No
Yes
Yes
No

[deepak prashad]

yes AskMe.class exist in the bin folder after compiling

[deepak prashad]

i am using class without package

[deepak prashad]

C:\Users\abhijeet\Java\jdk1.6.0\bin>dir *.class
Volume in drive C has no label.
Volume Serial Number is B27F-753E

Directory of C:\Users\abhijeet\Java\jdk1.6.0\bin

04/03/2012 02:13 PM 813 AskMe.class
04/03/2012 01:33 PM 438 Example.class
04/03/2012 02:13 PM 500 Question.class
04/03/2012 02:13 PM 289 SharedConstants.class
4 File(s) 2,040 bytes
0 Dir(s) 57,515,016,192 bytes free

C:\Users\abhijeet\Java\jdk1.6.0\bin>java AskMe
Exception in thread "main" java.lang.NoClassDefFoundError: AskMe
C:\Users\abhijeet\Java\jdk1.6.0\bin>java Example
Exception in thread "main" java.lang.NoClassDefFoundError: Example

i am so tensed please help me to solve this problem

[Campbell Ritchie]

Seetharaman Venkatasamy wrote:

javac askme.java compiled successfully

On Windows®, the OS can pass the argument to javac in a case-insensitive fashion.