Lab 1008, 2.4 homework - TreeSet iterator:
import java.util.TreeSet;
import java.util.Iterator;
import java.util.*;
public class Main {
public static void main(String[] args) {
// TODO code application logic here
TreeSet ts = new TreeSet();
ts.add("one") ;
ts.add("two") ;
// HERE comes the problem, trying to add the Integer(1), (2) and (3)
ts.add(new Integer(1)) ;
ts.add(new Integer(2)) ;
ts.add(new Integer(3)) ;
MyOwnClass obj1 = new MyOwnClass( );
ts.add(obj1) ;
}
}
Result is:
Exception in thread "main" java.lang.ClassCastException: java.lang.String
cannot be cast to java.lang.Integer
at java.lang.Integer.compareTo(Integer.java:35)
at java.util.TreeMap.put(TreeMap.java:545)
at java.util.TreeSet.add(TreeSet.java:238)
at mytreeset.Main.main(Main.java:21)
Java Result: 1
-------------------------------------------------------------------------------------------
MyOwnClass obj1 = new MyOwnClass( );
ts.add(obj1) ;
If I add the two rows above, adding the MyOwnClass obj1, which is properly
created in another file,
then comes an even longer list of errors that didn't happen when applying this
same method ADD() in LinkedList, ArrayList and HashSet
Exception in thread "main" java.lang.NoClassDefFoundError: mytreeset/MyOwnClass
at mytreeset.Main.main(Main.java:16)
Caused by: java.lang.ClassNotFoundException: mytreeset.MyOwnClass
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
Why can't I add objects to the TreeSet, while I could add them with not
exceptions in the case of LinkedList, ArrayList and HashSet ?
Thank you!!
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/javaprogrammingwithpassion?hl=en
-~----------~----~----~----~------~----~------~--~---
