Question

I am learning Java from scratch. I installed the JDK, and I got the Hello World Program running. I am trying to run a simple accountdemo program. In Account.java, I have :

public class Account 
{
    protected double balance;

    // Constructor to initialize balance
    public Account( double amount )
{
    balance = amount;
}

    // Overloaded constructor for empty balance
    public Account()
{
    balance = 0.0;
}

    public void deposit( double amount )
{
    balance += amount;
}

    public double withdraw( double amount )
{
            // See if amount can be withdrawn
    if (balance >= amount)
    {
        balance -= amount;
                    return amount;
    }
    else
            // Withdrawal not allowed
                    return 0.0;
}

    public double getbalance()
{
            return balance;
}
}  

On compiling this, I got the Account.class. In accountdemo.java, I have this

class AccountDemo
{

 public static void main(String args[])
 {
 Account my_account = new Account();
 my_account.deposit(250.00);
 System.out.println("Current balance " + my_account.getbalance());
 my_account.withdraw(80.00);
 System.out.println("Remaining balance" + my_account.getbalance());
}


 }

On compiling this, I got AccountDemo.class. But, when I try to run this as an application, I get the error java.lang.NoClassDefFoundError:
C:\Users\roymustang/NT\Documents\javaprogram\accountdemo/java

I have set the classpath to : C:\Users\roymustang.NT\Documents\javaprogram

Am I missing anything obvious? Like mismatched uppercase or something?

EDIT : Not homework, just trying to learn.

I am using Textpad, http://www.textpad.com/ . It has an option run commands. So, I have configured it to run javac.exe (C:\Program Files\SDK\jdk\bin\javac.exe $File $FileDir)

and run as application by java.exe ( C:\Program Files\SDK\jdk\bin\java.exe $File $FileDir)

Answer 1

Hi there I’ll assume that you are trying to run this using no java IDE e.g. Eclipse or Netbeans. I tested your code and they worked just fine.

C:>java AccountDemo
Current balance 250.0
Remaining balance170.0

Your error Message is:

java.lang.NoClassDefFoundError:
C:\Users\roymustang/NT\Documents\javaprogram\accountdemo/java

meaning you used:

java accountdemo

to run your program. Remember that Java is case sensitive this can be corrected by using this.

java AccountDemo

Happy Coding ^_^