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      1 /**
      2  * Copyright 2006-2017 the original author or authors.
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package org.objenesis.tck.search;
     17 
     18 import org.objenesis.instantiator.ObjectInstantiator;
     19 import org.objenesis.strategy.PlatformDescription;
     20 import org.objenesis.tck.candidates.SerializableNoConstructor;
     21 
     22 import java.io.Serializable;
     23 import java.lang.reflect.Constructor;
     24 import java.lang.reflect.InvocationTargetException;
     25 import java.util.Iterator;
     26 import java.util.SortedSet;
     27 
     28 /**
     29  * This class will try every available instantiator on the platform to see which works.
     30  *
     31  * @author Henri Tremblay
     32  */
     33 public class SearchWorkingInstantiator implements Serializable { // implements Serializable just for the test
     34 
     35     private SearchWorkingInstantiatorListener listener;
     36 
     37     public static void main(String[] args) throws Exception {
     38         System.out.println();
     39         System.out.println(PlatformDescription.describePlatform());
     40         System.out.println();
     41 
     42         SearchWorkingInstantiator searchWorkingInstantiator = new SearchWorkingInstantiator(new SystemOutListener());
     43         searchWorkingInstantiator.searchForInstantiator(SerializableNoConstructor.class);
     44     }
     45 
     46     public SearchWorkingInstantiator(SearchWorkingInstantiatorListener listener) {
     47         this.listener = listener;
     48     }
     49 
     50     public void searchForInstantiator(Class<?> toInstantiate) {
     51         SortedSet<String> classes = ClassEnumerator.getClassesForPackage(ObjectInstantiator.class.getPackage());
     52 
     53         for (Iterator<String> it = classes.iterator(); it.hasNext();) {
     54             String className = it.next();
     55 
     56             // Skip if inner class of isn't named like a instantiator
     57             if(className.contains("$") || !className.endsWith("Instantiator")) {
     58                continue;
     59             }
     60 
     61            Class<?> c = null;
     62            try {
     63               c = Class.forName(className);
     64            }
     65            catch(Exception e) {
     66               listener.instantiatorUnsupported(c, e);
     67               continue;
     68            }
     69 
     70            if(c.isInterface() || !ObjectInstantiator.class.isAssignableFrom(c)) {
     71                 continue;
     72            }
     73 
     74             Constructor<?> constructor;
     75             try {
     76                 constructor = c.getConstructor(Class.class);
     77             } catch (NoSuchMethodException e) {
     78                 throw new RuntimeException(e);
     79             }
     80 
     81             try {
     82                 ObjectInstantiator<?> instantiator =
     83                         (ObjectInstantiator<?>) constructor.newInstance(toInstantiate);
     84                 instantiator.newInstance();
     85                 listener.instantiatorSupported(c);
     86             }
     87             catch(Exception e) {
     88                 Throwable t = (e instanceof InvocationTargetException) ? e.getCause() : e;
     89                 listener.instantiatorUnsupported(c, t);
     90             }
     91         }
     92     }
     93 }
     94