estou tendo este erro: Exception in thread “main” java.lang.NullPointerException
segue as 3 classes utilizadas:
/*public class Fila {
private No first;
private No last;
private int size;
public Fila(){
first = null;
last = null;
size = 0;
}
public boolean isEmpty(){
return first == null;
}
public void add(String name, int idade){
No newNode = new No(name, idade);
No aux = first;
if(isEmpty()){
first = newNode;
last = newNode;
}if(first.getPreferencia() < newNode.getPreferencia()){
first = newNode;
first.setNext(aux);
}else{
while(aux.getNext() != null && (aux.getNext().getPreferencia() >= newNode.getPreferencia())){
aux = aux.getNext();
}
newNode.setNext(aux.getNext());
aux.setNext(newNode);
}
size++;
}
public No remove(){
if(isEmpty()){
return null;
}
No aux = first;
first = first.getNext();
if(first == null){
last = null;
}
size --;
return aux;
}
public String show(){
String out = "";
No aux = first;
while(aux != null){
out += aux.getName() + aux.getPreferencia() + "-";
aux = aux.getNext();
}
return out;
}
public int size(){
return size;
}
}
*/public class No {
private String name;
private int preferencial;
private No next;
public No(String name, int preferencial){
this.name = name;
this.preferencial = preferencial;
next = null;
}
public String getName(){
return name;
}
public void setName(String name){
this.name = name;
}
public int getPreferencia(){
return preferencial;
}
public No getNext(){
return next;
}
public void setNext(No next){
this.next = next;
}
}
*/
public class Main {
public static void main(String[] args) {
Fila fila = new Fila();
fila.add("Huguinho",0);
fila.add("Zezinho",1);
fila.add("Luizinho",1);
System.out.println(fila.show());
}
}
*/
