How do I use Java Generics with Lookup?

As of NetBeans 6, a number of convenience methods have been added to lookup, and support for Java generics has been added to Lookup. The following are differences (assume that lkp is a [[DevFaqLookup| Lookup]]):

NB 5.x Code NB 6 Code

NB 5.x Code	NB 6 Code
`DataObject dob = (DataObject) lkp.lookup(DataObject.class)`	`DataObject dob = lkp.lookup(DataObject.class)`
`Lookup.Result r = lkp.lookup(new Lookup.Template(X.class))`	`Lookup.Result<? extends X> r = lkp.lookupResult(X.class)`
`Collection c = r.allInstances()`	`Collection<? extends X> c = r.allInstances()`
`Lookup.Template t = new Lookup.Template(X.class);` `Lookup.Result r = lkp.lookup(t);` `Collection c = r.allInstances();`	`Collection<? extends X> c = lkp.lookupAll(X.class);`
`Lookup.Template t = new Lookup.Template(X.class);` Lookup.Result r = lkp.lookup(t); Collection c = r.allInstances(); ` `for (Iterator it=c.iterator(); it.hasNext();) { X x = (X) it.next(); //do something with x `}`	`for (X x : lkp.lookupAll(X.class)) {` `//do something with x` `}`

DataObject dob = (DataObject) lkp.lookup(DataObject.class)

DataObject dob = lkp.lookup(DataObject.class)

Lookup.Result r = lkp.lookup(new Lookup.Template(X.class))

Lookup.Result<? extends X> r = lkp.lookupResult(X.class)

Collection c = r.allInstances()

Collection<? extends X> c = r.allInstances()

Lookup.Template t = new Lookup.Template(X.class);


Lookup.Result r = lkp.lookup(t);

Collection c = r.allInstances();

Collection<? extends X> c = lkp.lookupAll(X.class);

Lookup.Template t = new Lookup.Template(X.class);


Lookup.Result r = lkp.lookup(t);
Collection c = r.allInstances();
`
`for (Iterator it=c.iterator(); it.hasNext();) {
  X x = (X) it.next();
  //do something with x

}

for (X x : lkp.lookupAll(X.class)) {


  //do something with x

}

Generics work well with JDK-5-style for-loops:

for (SomeService s : Lookup.getDefault().lookupAll(SomeService.class)) {
    // ...
}

Apache NetBeans 23

How do I use Java Generics with Lookup?