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1
57
58 package org.apache.commons.discovery.tools;
59
60 import java.util.Enumeration  ;
61 import java.util.Vector ;
62
63 import org.apache.commons.discovery.ResourceClass;
64 import org.apache.commons.discovery.listeners.GatherResourceClassesListener;
65 import org.apache.commons.discovery.resource.ClassLoaders;
66 import org.apache.commons.discovery.resource.classes.DiscoverClasses;
67 import org.apache.commons.discovery.resource.names.DiscoverServiceNames;
68
69
70
92 public class Service
93 {
94
96 protected Service() {
97 }
98
99
107 public static Enumeration providers(Class spiClass) {
108 return providers(new SPInterface(spiClass), null);
109 }
110
111
118 public static Enumeration providers(final SPInterface spi,
119 ClassLoaders loaders)
120 {
121 if (loaders == null) {
122 loaders = ClassLoaders.getAppLoaders(spi.getSPClass(),
123 Service.class,
124 true);
125 }
126
127
128 GatherResourceClassesListener listener = new GatherResourceClassesListener();
129
130 DiscoverClasses classDiscovery = new DiscoverClasses(loaders);
131 classDiscovery.setListener(listener);
132
133 DiscoverServiceNames discoverServices = new DiscoverServiceNames(loaders);
134 discoverServices.setListener(classDiscovery);
135 discoverServices.find(spi.getSPName());
136
137 final Vector results = listener.getResourceClasses();
138
139 return new Enumeration () {
140 private Object obj = null;
141 private int idx = 0;
142
143 public boolean hasMoreElements() {
144 if (obj == null) {
145 obj = getNextElement();
146 }
147 return obj != null;
148 }
149
150 public Object nextElement() {
151 Object o = obj;
152 obj = null;
153 return o;
154 }
155
156 private Object getNextElement() {
157 while (idx < results.size()) {
158 try {
159 return spi.newInstance(((ResourceClass)results.get(idx++)).loadClass());
160 } catch (Exception e) {
161 }
163 }
164 return null;
165 }
166 };
167 }
168 }
169 |
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