LinkQueue by java

class LQueue<Type> {
    private class LQNode {
        Type data;
        LQNode next;
        
        public LQNode(Type d) {
            // TODO Auto-generated constructor stub
            data = d;
            next = null;
        }
    }
    
    LQNode front;
    LQNode rear;
    
    public LQueue() {
        // TODO Auto-generated constructor stub
        front = null;
        rear = null;
    }
    
    private boolean IsEmpty () {
        return front == null;
    }
    
    public boolean EnLQueue(Type d) {
        LQNode node = new LQNode(d);
        
        if (front == null)
            front = node;
        else 
            rear.next = node;
        
        rear = node;
        
        return true;
    }
    
    public Type DeLQueue() {
        LQNode node;
        
        if (IsEmpty())
            return null;

        node = front;
        front = front.next;
        return node.data;
    }
}

public class LinkQueue {
    public static void main(String[] args) {
        String d;
        String string[] = {"Create", "LinkQueue", "Success", "!"};
        LQueue<String> q = new LQueue<String>();
        
        for (int i = 0; i < string.length; i++) {
            q.EnLQueue(string[i]);
        }
        
        while ((d = q.DeLQueue()) != null)
            System.out.print(d + " ");
            
    }
}