110 * section in <em>Java Tutorial</em>.
111 *
112 * @author Blake Sullivan
113 * @author Laurence P. G. Cable
114 * @author Jeff Dunn
115 */
116 public class DataFlavor implements Externalizable, Cloneable {
117
118 private static final long serialVersionUID = 8367026044764648243L;
119 private static final Class<InputStream> ioInputStreamClass = InputStream.class;
120
121 /**
122 * Tries to load a class from: the bootstrap loader, the system loader,
123 * the context loader (if one is present) and finally the loader specified.
124 *
125 * @param className the name of the class to be loaded
126 * @param fallback the fallback loader
127 * @return the class loaded
128 * @exception ClassNotFoundException if class is not found
129 */
130 protected final static Class<?> tryToLoadClass(String className,
131 ClassLoader fallback)
132 throws ClassNotFoundException
133 {
134 ReflectUtil.checkPackageAccess(className);
135 try {
136 SecurityManager sm = System.getSecurityManager();
137 if (sm != null) {
138 sm.checkPermission(new RuntimePermission("getClassLoader"));
139 }
140 ClassLoader loader = ClassLoader.getSystemClassLoader();
141 try {
142 // bootstrap class loader and system class loader if present
143 return Class.forName(className, true, loader);
144 }
145 catch (ClassNotFoundException exception) {
146 // thread context class loader if and only if present
147 loader = Thread.currentThread().getContextClassLoader();
148 if (loader != null) {
149 try {
150 return Class.forName(className, true, loader);
151 }
152 catch (ClassNotFoundException e) {
153 // fallback to user's class loader
154 }
155 }
156 }
157 } catch (SecurityException exception) {
158 // ignore secured class loaders
159 }
160 return Class.forName(className, true, fallback);
161 }
162
163 /*
164 * private initializer
165 */
166 static private DataFlavor createConstant(Class<?> rc, String prn) {
167 try {
168 return new DataFlavor(rc, prn);
169 } catch (Exception e) {
170 return null;
171 }
172 }
173
174 /*
175 * private initializer
176 */
177 static private DataFlavor createConstant(String mt, String prn) {
178 try {
179 return new DataFlavor(mt, prn);
180 } catch (Exception e) {
181 return null;
182 }
183 }
184
185 /*
186 * private initializer
187 */
188 static private DataFlavor initHtmlDataFlavor(String htmlFlavorType) {
189 try {
190 return new DataFlavor ("text/html; class=java.lang.String;document=" +
191 htmlFlavorType + ";charset=Unicode");
192 } catch (Exception e) {
193 return null;
194 }
195 }
196
197 /**
198 * The <code>DataFlavor</code> representing a Java Unicode String class,
199 * where:
200 * <pre>
201 * representationClass = java.lang.String
202 * mimeType = "application/x-java-serialized-object"
203 * </pre>
204 */
205 public static final DataFlavor stringFlavor = createConstant(java.lang.String.class, "Unicode String");
206
207 /**
208 * The <code>DataFlavor</code> representing a Java Image class,
|
110 * section in <em>Java Tutorial</em>.
111 *
112 * @author Blake Sullivan
113 * @author Laurence P. G. Cable
114 * @author Jeff Dunn
115 */
116 public class DataFlavor implements Externalizable, Cloneable {
117
118 private static final long serialVersionUID = 8367026044764648243L;
119 private static final Class<InputStream> ioInputStreamClass = InputStream.class;
120
121 /**
122 * Tries to load a class from: the bootstrap loader, the system loader,
123 * the context loader (if one is present) and finally the loader specified.
124 *
125 * @param className the name of the class to be loaded
126 * @param fallback the fallback loader
127 * @return the class loaded
128 * @exception ClassNotFoundException if class is not found
129 */
130 protected static final Class<?> tryToLoadClass(String className,
131 ClassLoader fallback)
132 throws ClassNotFoundException
133 {
134 ReflectUtil.checkPackageAccess(className);
135 try {
136 SecurityManager sm = System.getSecurityManager();
137 if (sm != null) {
138 sm.checkPermission(new RuntimePermission("getClassLoader"));
139 }
140 ClassLoader loader = ClassLoader.getSystemClassLoader();
141 try {
142 // bootstrap class loader and system class loader if present
143 return Class.forName(className, true, loader);
144 }
145 catch (ClassNotFoundException exception) {
146 // thread context class loader if and only if present
147 loader = Thread.currentThread().getContextClassLoader();
148 if (loader != null) {
149 try {
150 return Class.forName(className, true, loader);
151 }
152 catch (ClassNotFoundException e) {
153 // fallback to user's class loader
154 }
155 }
156 }
157 } catch (SecurityException exception) {
158 // ignore secured class loaders
159 }
160 return Class.forName(className, true, fallback);
161 }
162
163 /*
164 * private initializer
165 */
166 private static DataFlavor createConstant(Class<?> rc, String prn) {
167 try {
168 return new DataFlavor(rc, prn);
169 } catch (Exception e) {
170 return null;
171 }
172 }
173
174 /*
175 * private initializer
176 */
177 private static DataFlavor createConstant(String mt, String prn) {
178 try {
179 return new DataFlavor(mt, prn);
180 } catch (Exception e) {
181 return null;
182 }
183 }
184
185 /*
186 * private initializer
187 */
188 private static DataFlavor initHtmlDataFlavor(String htmlFlavorType) {
189 try {
190 return new DataFlavor ("text/html; class=java.lang.String;document=" +
191 htmlFlavorType + ";charset=Unicode");
192 } catch (Exception e) {
193 return null;
194 }
195 }
196
197 /**
198 * The <code>DataFlavor</code> representing a Java Unicode String class,
199 * where:
200 * <pre>
201 * representationClass = java.lang.String
202 * mimeType = "application/x-java-serialized-object"
203 * </pre>
204 */
205 public static final DataFlavor stringFlavor = createConstant(java.lang.String.class, "Unicode String");
206
207 /**
208 * The <code>DataFlavor</code> representing a Java Image class,
|