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1   /*
2    * #%L
3    * prolobjectlink-jpi
4    * %%
5    * Copyright (C) 2019 Prolobjectlink Project
6    * %%
7    * Permission is hereby granted, free of charge, to any person obtaining a copy
8    * of this software and associated documentation files (the "Software"), to deal
9    * in the Software without restriction, including without limitation the rights
10   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11   * copies of the Software, and to permit persons to whom the Software is
12   * furnished to do so, subject to the following conditions:
13   * 
14   * The above copyright notice and this permission notice shall be included in
15   * all copies or substantial portions of the Software.
16   * 
17   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23   * THE SOFTWARE.
24   * #L%
25   */
26  package io.github.prolobjectlink.prolog;
27  
28  import java.lang.reflect.Constructor;
29  import java.util.logging.Level;
30  import java.util.logging.Logger;
31  
32  import javax.script.ScriptEngine;
33  import javax.script.ScriptEngineManager;
34  
35  /**
36   * Bootstrap platform class. Contains {@link #getProvider(Class)} method that
37   * return an instance of Prolog Provider from the given class. Alternatively can
38   * be used {@link #getProvider()} for create and return a {@link PrologProvider}
39   * using Java Platform discovery pattern.
40   * 
41   * @author Jose Zalacain
42   * @since 1.0
43   */
44  public final class Prolog {
45  
46  	private Prolog() {
47  	}
48  
49  	/**
50  	 * Create and return an instance of Prolog Provider using Java Platform
51  	 * discovery pattern.
52  	 * 
53  	 * @return an instance of Prolog Provider from the given class.
54  	 * @since 1.1
55  	 */
56  	public static PrologProvider getProvider() {
57  		ScriptEngineManager manager = new ScriptEngineManager();
58  		ScriptEngine engine = manager.getEngineByName("prolog");
59  		return ((PrologScriptEngine) engine).getProvider();
60  	}
61  
62  	/**
63  	 * Create and return an instance of Prolog Provider using the Prolog Provider
64  	 * class name.
65  	 * 
66  	 * @return an instance of Prolog Provider from the given class.
67  	 * @since 1.1
68  	 */
69  	public static PrologProvider getProvider(String className) {
70  		PrologProvider provider = null;
71  		try {
72  			return getProvider(Class.forName(className));
73  		} catch (ClassNotFoundException e) {
74  			Logger.getLogger(Prolog.class.getName()).log(Level.FINEST, null, e);
75  		}
76  		return provider;
77  	}
78  
79  	/**
80  	 * Create and return an instance of Prolog Provider from the given class.
81  	 * 
82  	 * @param providerClass Prolog Provider class used to create a new instance.
83  	 * @return an instance of Prolog Provider from the given class.
84  	 * @since 1.0
85  	 */
86  	public static PrologProvider getProvider(Class<?> providerClass) {
87  		PrologProvider provider = null;
88  		try {
89  			Constructor<?> constructor = providerClass.getDeclaredConstructor();
90  			constructor.setAccessible(true);
91  			provider = (PrologProvider) providerClass.newInstance();
92  			constructor.setAccessible(false);
93  		} catch (InstantiationException e) {
94  			Logger.getLogger(Prolog.class.getName()).log(Level.FINEST, null, e);
95  		} catch (IllegalAccessException e) {
96  			Logger.getLogger(Prolog.class.getName()).log(Level.FINEST, null, e);
97  		} catch (NoSuchMethodException e) {
98  			Logger.getLogger(Prolog.class.getName()).log(Level.FINEST, null, e);
99  		} catch (SecurityException e) {
100 			Logger.getLogger(Prolog.class.getName()).log(Level.FINEST, null, e);
101 		}
102 		return provider;
103 	}
104 
105 }