| /** |
| * 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. |
| */ |
| package org.apache.hadoop.conf; |
| |
| import java.util.List; |
| |
| import junit.framework.TestCase; |
| |
| public class TestGetInstances extends TestCase { |
| |
| interface SampleInterface {} |
| |
| interface ChildInterface extends SampleInterface {} |
| |
| static class SampleClass implements SampleInterface { |
| SampleClass() {} |
| } |
| |
| static class AnotherClass implements ChildInterface { |
| AnotherClass() {} |
| } |
| |
| /** |
| * Makes sure <code>Configuration.getInstances()</code> returns |
| * instances of the required type. |
| */ |
| public void testGetInstances() throws Exception { |
| Configuration conf = new Configuration(); |
| |
| List<SampleInterface> classes = |
| conf.getInstances("no.such.property", SampleInterface.class); |
| assertTrue(classes.isEmpty()); |
| |
| conf.set("empty.property", ""); |
| classes = conf.getInstances("empty.property", SampleInterface.class); |
| assertTrue(classes.isEmpty()); |
| |
| conf.setStrings("some.classes", |
| SampleClass.class.getName(), AnotherClass.class.getName()); |
| classes = conf.getInstances("some.classes", SampleInterface.class); |
| assertEquals(2, classes.size()); |
| |
| try { |
| conf.setStrings("some.classes", |
| SampleClass.class.getName(), AnotherClass.class.getName(), |
| String.class.getName()); |
| conf.getInstances("some.classes", SampleInterface.class); |
| fail("java.lang.String does not implement SampleInterface"); |
| } catch (RuntimeException e) {} |
| |
| try { |
| conf.setStrings("some.classes", |
| SampleClass.class.getName(), AnotherClass.class.getName(), |
| "no.such.Class"); |
| conf.getInstances("some.classes", SampleInterface.class); |
| fail("no.such.Class does not exist"); |
| } catch (RuntimeException e) {} |
| } |
| } |