Custom data structure

package Node;

 class Node1<T> {
private T data;
private Node1<T> next;
private Node1<T> previous;
public Node1<T> getPrevious() {
return previous;
}
public void setPrevious(Node1<T> previous) {
this.previous = previous;
}
public T getData() {
return data;
}
public void setData(T data) {
this.data = data;
}
public Node1<T> getNext() {
return next;
}
public void setNext(Node1<T> next,Node1<T> previous) {
this.next = next;
this.previous=previous;
}
Node1(T data,Node1<T> next){
this.data=data;
this.next=next;

}
public String toString(){
return this.data.toString()+this.next==null?"":","+this.next.toString();
}

}
 public class Node{
public static void main(String[] argv) throws Exception {
Node1<String> node1=new Node1<String>("abc", null);
Node1<String> node3=new Node1<String>("abcde", null);
Node1<String> node2=new Node1<String>("def", node1);
System.out.println(node2.getData());
System.out.println(node2.getNext().getData());
System.out.println(node2.toString());
;
}

 }