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Thread: cant run the program with 2 classes

  1. #1
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    Unhappy cant run the program with 2 classes

    Hi there

    i copied below coding from the book.but still cant run the program.i noticed there are two class , they are class student and class obj.i tried separate both class in different class file -> Student.java/Student.class and obj.java/obj.class , but i still cant run the program.Pls help.

    Thanks in advance



    ----------------------------------
    public class Student   {
     
    private String name; 
    private int matricNo; 
    private int yearOfBirth; 
    private int age; 
    private double fees;
    private int numberOfCoursesRegistered; 
    private String[ ] subjectName; 
    private boolean registered= false;
     
    public Student(String NAME, int MATRIC, int B_YEAR) { 
     
    name= NAME;
    yearOfBirth=B_YEAR; 
    matricNo= MATRIC; 
    numberOfCoursesRegistered=0;
    subjectName= new String[3];
     
    calculateAge();
     
    }
     
    private void calculateAge(){
     
    int currentYear=2008;
    age= currentYear-yearOfBirth;
     
    }//calculateAge
     
     
     
    public void calculateFee(){ 
     
    if (registered==true) 
     
    fees=numberOfCoursesRegistered*350; 
     
    }//calculateFee
     
     
     
    public void registerSubject (String subject1){
     
    if (registered==false) {
     
    subjectName[0]=subject1;	
    numberOfCoursesRegistered=1;
    registered=true;
     
    }	
     
    else
     
      System.out.println("You already registered");
     
     
    }// registerSubject
     
     
     
     
    public void registerSubject (String subject1, String subject2){
     
    if (registered==false) {
     
      subjectName[0]=subject1;
      subjectName[1]=subject2; 
      numberOfCoursesRegistered=2; 
      registered=true; 
    }
     
    else	
     
      System.out.println("You already registered");  
     
    }// registerSubject 
     
    public   void   registerSubject   (String   subject1,   String   subject2,   String subject3){
     
     
    if (registered==false) {
     
    subjectName[0]=subject1; 
    subjectName[1]=subject2; 
    subjectName[3]=subject3; 
    numberOfCoursesRegistered=3; 
    registered=true; 
     
    } 
     
    else
     
      System.out.println("You already registered"); 
    }
     
    // registerSubject 
     
     
    public void displaylnfo ( ) { 
     
      if (registered==true){ 
     
    System.out.println("Name: " + name); 
    System.out.println("Matric: " + matricNo); 
    System.out.println("Year of Birth: " + yearOfBirth); 
    System.out.println("age " +age); 
    System.out.println("Fees: " + fees);
     
    System.out.println("No of courses registered:+numberOfCoursesRegistered"); 
     
    System.out.println("Courses registered are:"); 
     
    for (int count=0; count < numberOfCoursesRegistered; count++) 
     
    System.out.println(subjectName[count]); 
     
    } //if 
     
    else 
     
      System.out.println("Information cannot be displayed because you have not registered");
     
    } //displayInfo 
    }//class
     
    ---------------------------------------------------------------------------------------
     
    class obj{
     
    public static void main(String[]args){
     
    Student John = new Student ("John Smith" , 2345 , 1969);
     
    John.registerSubject("Java Programming");
    John.calculateFee();
     
    }
    }
    Last edited by copeg; November 14th, 2010 at 08:55 PM.


  2. #2
    Administrator copeg's Avatar
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    Default Re: cant run the program with 2 classes

    For future reference, please surround your code with the [highlight=java][/highlight] tags.

    Please define "can't run the program". What errors are you receiving? Are the class files in the same directory?

  3. #3
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    Default Re: cant run the program with 2 classes

    Hi

    Thank You so much for your reply.below is the command i typed in DOS and the result.
    Yes , i copied both class in same directory -> C:\Program Files\Java\jdk1.6.0_22\bin

    -------------------------------------------------------------------------------------------

    C:\Program Files\Java\jdk1.6.0_22\bin>java obj.java
    Exception in thread "main" java.lang.NoClassDefFoundError: obj/java
    Caused by: java.lang.ClassNotFoundException: obj.java
    at java.net.URLClassLoader$1.run(URLClassLoader.java: 202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.j ava:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:3 07)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launche r.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:2 48)
    Could not find the main class: obj.java. Program will exit.

    C:\Program Files\Java\jdk1.6.0_22\bin>java Student
    Exception in thread "main" java.lang.NoSuchMethodError: main

  4. #4
    Member Darryl.Burke's Avatar
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    Default Re: cant run the program with 2 classes

    Yes , i copied both class in same directory -> C:\Program Files\Java\jdk1.6.0_22\bin
    no No No NO NO! It's extremely poor practice to place user files in the program folder tree.

    C:\Program Files\Java\jdk1.6.0_22\bin>java obj.java
    When you give that command, the Java runtime looks for a class named java, which has a package obj; statement and resides in a obj folder subordinate to the current working directory.

    http://download.oracle.com/javase/tu...ems/index.html

    db

  5. #5
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    Default Re: cant run the program with 2 classes

    please wirte
    {Student st=new student();
    ob.yourrequred method.}
    Last edited by talha07; November 17th, 2010 at 03:43 PM.

  6. #6
    Member Darryl.Burke's Avatar
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    Default Re: cant run the program with 2 classes

    Quote Originally Posted by talha07 View Post
    please wirte
    {Student st=new student();
    ob.yourrequred method.}
    Please don't post garbage.

    db

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