Hit Unbehandelte Exception java.lang.NullPointerException

[Jonas Sprenger]

Was bedeutet diese Fehlermeldung ??

Bedanke mich schon mal bei euch

[Thomas Tasior]

Hallo Jonas, hier die JavaDoc dazu:

Thrown when an application attempts to use null in a case where an object is required. These include:

Calling the instance method of a null object.
Accessing or modifying the field of a null object.
Taking the length of null as if it were an array.
Accessing or modifying the slots of null as if it were an array.
Throwing null as if it were a Throwable value.

Applications should throw instances of this class to indicate other illegal uses of the null object.

und noch ein Beispiel:

<pre>
public class Test
{
public static void main(String[] args)
{
String s = "Hallo Welt!";
System.out.println(s);
s = null;
System.out.println(s.toString());
}
}

</pre&gt