| // |
| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License. |
| // |
| |
| = DevFaqLookupGenerics |
| :jbake-type: wiki |
| :jbake-tags: wiki, devfaq, needsreview |
| :jbake-status: published |
| |
| === 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 |
| |
| |`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: |
| |
| [source,java] |
| ---- |
| |
| for (SomeService s : Lookup.getDefault().lookupAll(SomeService.class)) { |
| // ... |
| } |
| ---- |
| |
| === Apache Migration Information |
| |
| The content in this page was kindly donated by Oracle Corp. to the |
| Apache Software Foundation. |
| |
| This page was exported from link:http://wiki.netbeans.org/DevFaqLookupGenerics[http://wiki.netbeans.org/DevFaqLookupGenerics] , |
| that was last modified by NetBeans user Tboudreau |
| on 2010-02-19T00:29:05Z. |
| |
| |
| *NOTE:* This document was automatically converted to the AsciiDoc format on 2018-01-10, and needs to be reviewed. |