98 * native code.
99 *
100 * <p> It is also possible to manually add service providers not found
101 * automatically, as well as to remove those that are using the
102 * interfaces of the <code>ServiceRegistry</code> class. Thus
103 * the application may customize the contents of the registry as it
104 * sees fit.
105 *
106 * <p> For more details on declaring service providers, and the JAR
107 * format in general, see the <a
108 * href="{@docRoot}/../technotes/guides/jar/jar.html">
109 * JAR File Specification</a>.
110 *
111 */
112 public final class IIORegistry extends ServiceRegistry {
113
114 /**
115 * A <code>Vector</code> containing the valid IIO registry
116 * categories (superinterfaces) to be used in the constructor.
117 */
118 private static final Vector initialCategories = new Vector(5);
119
120 static {
121 initialCategories.add(ImageReaderSpi.class);
122 initialCategories.add(ImageWriterSpi.class);
123 initialCategories.add(ImageTranscoderSpi.class);
124 initialCategories.add(ImageInputStreamSpi.class);
125 initialCategories.add(ImageOutputStreamSpi.class);
126 }
127
128 /**
129 * Set up the valid service provider categories and automatically
130 * register all available service providers.
131 *
132 * <p> The constructor is private in order to prevent creation of
133 * additional instances.
134 */
135 private IIORegistry() {
136 super(initialCategories.iterator());
137 registerStandardSpis();
138 registerApplicationClasspathSpis();
181 registerServiceProvider(new RAFImageInputStreamSpi());
182 registerServiceProvider(new RAFImageOutputStreamSpi());
183
184 registerInstalledProviders();
185 }
186
187 /**
188 * Registers all available service providers found on the
189 * application class path, using the default
190 * <code>ClassLoader</code>. This method is typically invoked by
191 * the <code>ImageIO.scanForPlugins</code> method.
192 *
193 * @see javax.imageio.ImageIO#scanForPlugins
194 * @see ClassLoader#getResources
195 */
196 public void registerApplicationClasspathSpis() {
197 // FIX: load only from application classpath
198
199 ClassLoader loader = Thread.currentThread().getContextClassLoader();
200
201 Iterator categories = getCategories();
202 while (categories.hasNext()) {
203 Class<IIOServiceProvider> c = (Class)categories.next();
204 Iterator<IIOServiceProvider> riter =
205 ServiceLoader.load(c, loader).iterator();
206 while (riter.hasNext()) {
207 try {
208 // Note that the next() call is required to be inside
209 // the try/catch block; see 6342404.
210 IIOServiceProvider r = riter.next();
211 registerServiceProvider(r);
212 } catch (ServiceConfigurationError err) {
213 if (System.getSecurityManager() != null) {
214 // In the applet case, we will catch the error so
215 // registration of other plugins can proceed
216 err.printStackTrace();
217 } else {
218 // In the application case, we will throw the
219 // error to indicate app/system misconfiguration
220 throw err;
221 }
222 }
223 }
224 }
225 }
226
227 private void registerInstalledProviders() {
228 /*
229 We need to load installed providers from the
230 system classpath (typically the <code>lib/ext</code>
231 directory in in the Java installation directory)
232 in the privileged mode in order to
233 be able read corresponding jar files even if
234 file read capability is restricted (like the
235 applet context case).
236 */
237 PrivilegedAction doRegistration =
238 new PrivilegedAction() {
239 public Object run() {
240 Iterator categories = getCategories();
241 while (categories.hasNext()) {
242 Class<IIOServiceProvider> c = (Class)categories.next();
243 for (IIOServiceProvider p : ServiceLoader.loadInstalled(c)) {
244 registerServiceProvider(p);
245 }
246 }
247 return this;
248 }
249 };
250
251 AccessController.doPrivileged(doRegistration);
252 }
253 }
|
98 * native code.
99 *
100 * <p> It is also possible to manually add service providers not found
101 * automatically, as well as to remove those that are using the
102 * interfaces of the <code>ServiceRegistry</code> class. Thus
103 * the application may customize the contents of the registry as it
104 * sees fit.
105 *
106 * <p> For more details on declaring service providers, and the JAR
107 * format in general, see the <a
108 * href="{@docRoot}/../technotes/guides/jar/jar.html">
109 * JAR File Specification</a>.
110 *
111 */
112 public final class IIORegistry extends ServiceRegistry {
113
114 /**
115 * A <code>Vector</code> containing the valid IIO registry
116 * categories (superinterfaces) to be used in the constructor.
117 */
118 private static final Vector<Class<?>> initialCategories = new Vector<>(5);
119
120 static {
121 initialCategories.add(ImageReaderSpi.class);
122 initialCategories.add(ImageWriterSpi.class);
123 initialCategories.add(ImageTranscoderSpi.class);
124 initialCategories.add(ImageInputStreamSpi.class);
125 initialCategories.add(ImageOutputStreamSpi.class);
126 }
127
128 /**
129 * Set up the valid service provider categories and automatically
130 * register all available service providers.
131 *
132 * <p> The constructor is private in order to prevent creation of
133 * additional instances.
134 */
135 private IIORegistry() {
136 super(initialCategories.iterator());
137 registerStandardSpis();
138 registerApplicationClasspathSpis();
181 registerServiceProvider(new RAFImageInputStreamSpi());
182 registerServiceProvider(new RAFImageOutputStreamSpi());
183
184 registerInstalledProviders();
185 }
186
187 /**
188 * Registers all available service providers found on the
189 * application class path, using the default
190 * <code>ClassLoader</code>. This method is typically invoked by
191 * the <code>ImageIO.scanForPlugins</code> method.
192 *
193 * @see javax.imageio.ImageIO#scanForPlugins
194 * @see ClassLoader#getResources
195 */
196 public void registerApplicationClasspathSpis() {
197 // FIX: load only from application classpath
198
199 ClassLoader loader = Thread.currentThread().getContextClassLoader();
200
201 Iterator<Class<?>> categories = getCategories();
202 while (categories.hasNext()) {
203 @SuppressWarnings("unchecked")
204 Class<IIOServiceProvider> c = (Class<IIOServiceProvider>)categories.next();
205 Iterator<IIOServiceProvider> riter =
206 ServiceLoader.load(c, loader).iterator();
207 while (riter.hasNext()) {
208 try {
209 // Note that the next() call is required to be inside
210 // the try/catch block; see 6342404.
211 IIOServiceProvider r = riter.next();
212 registerServiceProvider(r);
213 } catch (ServiceConfigurationError err) {
214 if (System.getSecurityManager() != null) {
215 // In the applet case, we will catch the error so
216 // registration of other plugins can proceed
217 err.printStackTrace();
218 } else {
219 // In the application case, we will throw the
220 // error to indicate app/system misconfiguration
221 throw err;
222 }
223 }
224 }
225 }
226 }
227
228 private void registerInstalledProviders() {
229 /*
230 We need to load installed providers from the
231 system classpath (typically the <code>lib/ext</code>
232 directory in in the Java installation directory)
233 in the privileged mode in order to
234 be able read corresponding jar files even if
235 file read capability is restricted (like the
236 applet context case).
237 */
238 PrivilegedAction<Object> doRegistration =
239 new PrivilegedAction<Object>() {
240 public Object run() {
241 Iterator<Class<?>> categories = getCategories();
242 while (categories.hasNext()) {
243 @SuppressWarnings("unchecked")
244 Class<IIOServiceProvider> c = (Class<IIOServiceProvider>)categories.next();
245 for (IIOServiceProvider p : ServiceLoader.loadInstalled(c)) {
246 registerServiceProvider(p);
247 }
248 }
249 return this;
250 }
251 };
252
253 AccessController.doPrivileged(doRegistration);
254 }
255 }
|