Class TestBuilderProxy

1	/*
2	* Copyright (c) 2019 Martin Davis.
3	*
4	* All rights reserved. This program and the accompanying materials
5	* are made available under the terms of the Eclipse Public License 2.0
6	* and Eclipse Distribution License v. 1.0 which accompanies this distribution.
7	* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v20.html
8	* and the Eclipse Distribution License is available at
9	*
10	* http://www.eclipse.org/org/documents/edl-v10.php.
11	*/
12	package org.locationtech.jts.util;
13
14	import java.lang.reflect.Method;
15
16	import org.locationtech.jts.geom.Geometry;
17
18	/**
19	* A proxy to call TestBuilder functions dynamically.
20	* If TestBuilder is not present, functions act as a no-op.
21	* <p>
22	* This class is somewhat experimental at the moment, so
23	* is not recommended for production use.
24	*
25	* @author Martin Davis
26	*
27	*/
28	public class TestBuilderProxy {
29
30	private static final String CLASS_FUNCTIONS_UTIL = "org.locationtech.jtstest.function.FunctionsUtil";
31	private static Class<?> tbClass;
32	private static Method methodShowIndicator;
33
34	private static void init() {
35	if (tbClass != null) return;
36	try {
37	tbClass = TestBuilderProxy.class.getClassLoader().loadClass(CLASS_FUNCTIONS_UTIL);
38	methodShowIndicator = tbClass.getMethod("showIndicator", Geometry.class);
39	}
40	catch (Exception ex) {
41	// Fail silently to avoid unexpected output in production
42	//System.err.println("TestBuilderProxy: Can't init");
43	}
44	}
45
46	/**
47	* Tests whether the proxy is active (i.e. the TestBuilder is available).
48	* This allows avoiding expensive geometry materialization if not needed.
49	*
50	* @return true if the proxy is active
51	*/
52	public static boolean isActive() {
53	init();
54	return tbClass != null;
55	}
56
57	// TODO: expose an option in the TestBuilder to make this inactive
58	// This will avoid a huge performance hit if the visualization is not needed
59
60	public static void showIndicator(Geometry geom) {
61	init();
62	if (methodShowIndicator == null) return;
63
64	try {
65	methodShowIndicator.invoke(null, geom);
66	} catch (Exception e) {
67	// Fail silently to avoid unexpected output in production
68	// Or perhaps should fail noisy, since at this point the function should be working?
69	}
70	}
71	}
72