package problems in java
<p>I write a source file and put that public class in a package : </p>

<pre><code>package abc;
public class Employee
{
    // Constructor
    public Employee(String name, double salary)
    {
        this.name = name;
        this.salary = salary;
    }

    // Methods
    public String getName()
    {
        return this.name;
    }

    public double getSalary()
    {
        return this.salary;
    }

    // instance field
    private String name;
    private double salary;
}    
</code></pre>

<p>Then I try to compile it using command: <strong>javac Employee.java</strong> , it generates a .class file in the same directory as the source file    </p>

<p>Now I try to use this package, so I write a source file :    </p>

<pre><code>import abc.*;
public class HelloWorld
{
    public static void main(String args[]){
        //System.out.println("hello world");

        Employee aEmployee = new Employee("David",1000);
        System.out.println(aEmployee.getName() + aEmployee.getSalary());
    }

}
</code></pre>

<p>I try to compile it using: <strong>javac HelloWorld.java</strong> , but it has a error says : <strong>package abc doesn't exist</strong>  </p>

<p>I have the following <strong>questions</strong>:<br>
1) Why did this error happen ?<br>
2) How to solve this problem ?<br>
3) Each time when I package some classes, where can I find the package to use afterwards  </p>

<p>I've read some docs about this, but that's so complex, can somebody explain it <strong>simply</strong> ?</p>
