01: /*
02: * Copyright (c) 2004 JETA Software, Inc. All rights reserved.
03: *
04: * Redistribution and use in source and binary forms, with or without modification,
05: * are permitted provided that the following conditions are met:
06: *
07: * o Redistributions of source code must retain the above copyright notice,
08: * this list of conditions and the following disclaimer.
09: *
10: * o Redistributions in binary form must reproduce the above copyright notice,
11: * this list of conditions and the following disclaimer in the documentation
12: * and/or other materials provided with the distribution.
13: *
14: * o Neither the name of JETA Software nor the names of its contributors may
15: * be used to endorse or promote products derived from this software without
16: * specific prior written permission.
17: *
18: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21: * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
22: * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23: * INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24: * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
25: * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26: * INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28: */
29:
30: package com.jeta.open.registry;
31:
32: import java.util.Hashtable;
33:
34: /**
35: * JETARegistry is a class that is used to manage objects and services for an
36: * application. Client classes can obtain an instance to well-known objects
37: * and/or services by using the JETARegistry. This class is not thread safe.
38: *
39: * @author Jeff Tassin
40: */
41: public class JETARegistry {
42: /**
43: * A hash of component names (String) to a named component (Object)
44: */
45: private static Hashtable m_components = new Hashtable();
46:
47: private static String NULL_HOLDER = "";
48:
49: /**
50: * @return a component that is registered with the given name. Null is
51: * returned if the component has not been registered.
52: */
53: synchronized public static Object lookup(String componentName) {
54: Object obj = m_components.get(componentName);
55: if (obj == NULL_HOLDER)
56: return null;
57: else
58: return obj;
59: }
60:
61: /**
62: * Register a component with the given name. If a component a component has
63: * already been registered, it is overwritten.
64: */
65: synchronized public static void rebind(String componentName,
66: Object componentImpl) {
67: if (componentImpl == null)
68: m_components.put(componentName, NULL_HOLDER);
69: else
70: m_components.put(componentName, componentImpl);
71: }
72:
73: /**
74: * Removes a registered component with the given name.
75: */
76: synchronized public static void remove(String componentName) {
77: m_components.remove(componentName);
78: }
79:
80: }
|