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Diffstat (limited to 'libjava/classpath/java/lang/reflect/InvocationHandler.java')
| -rw-r--r-- | libjava/classpath/java/lang/reflect/InvocationHandler.java | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/libjava/classpath/java/lang/reflect/InvocationHandler.java b/libjava/classpath/java/lang/reflect/InvocationHandler.java deleted file mode 100644 index 3d30afd..0000000 --- a/libjava/classpath/java/lang/reflect/InvocationHandler.java +++ /dev/null @@ -1,137 +0,0 @@ -/* java.lang.reflect.InvocationHandler - dynamically executes methods in - proxy instances - Copyright (C) 2001 Free Software Foundation, Inc. - -This file is part of GNU Classpath. - -GNU Classpath is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU Classpath is distributed in the hope that it will be useful, but -WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Classpath; see the file COPYING. If not, write to the -Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301 USA. - -Linking this library statically or dynamically with other modules is -making a combined work based on this library. Thus, the terms and -conditions of the GNU General Public License cover the whole -combination. - -As a special exception, the copyright holders of this library give you -permission to link this library with independent modules to produce an -executable, regardless of the license terms of these independent -modules, and to copy and distribute the resulting executable under -terms of your choice, provided that you also meet, for each linked -independent module, the terms and conditions of the license of that -module. An independent module is a module which is not derived from -or based on this library. If you modify this library, you may extend -this exception to your version of the library, but you are not -obligated to do so. If you do not wish to do so, delete this -exception statement from your version. */ - - -package java.lang.reflect; - -/** - * This interface defines an invocation handler. Suppose you are using - * reflection, and found a method that requires that its parameter - * be an object of a given interface. You want to call this method, - * but have no idea what classes implement that interface. So, you can - * create a {@link Proxy} instance, a convenient way to dynamically - * generate a class that meets all the necessary properties of that - * interface. But in order for the proxy instance to do any good, it - * needs to know what to do when interface methods are invoked! So, - * this interface is basically a cool wrapper that provides runtime - * code generation needed by proxy instances. - * - * <p>While this interface was designed for use by Proxy, it will also - * work on any object in general.</p> - * - * <p>Hints for implementing this class:</p> - * - * <ul> - * <li>Don't forget that Object.equals, Object.hashCode, and - * Object.toString will call this handler. In particular, - * a naive call to proxy.equals, proxy.hashCode, or proxy.toString - * will put you in an infinite loop. And remember that string - * concatenation also invokes toString.</li> - * <li>Obey the contract of the Method object you are handling, or - * the proxy instance will be forced to throw a - * {@link NullPointerException}, {@link ClassCastException}, - * or {@link UndeclaredThrowableException}.</li> - * <li>Be prepared to wrap/unwrap primitives as necessary.</li> - * <li>The Method object may be owned by a different interface than - * what was actually used as the qualifying type of the method - * invocation in the Java source code. This means that it might - * not always be safe to throw an exception listed as belonging - * to the method's throws clause.</li> - * </ul> - * - * <p><small>For a fun time, create an InvocationHandler that handles the - * methods of a proxy instance of the InvocationHandler interface!</small></p> - * - * @see Proxy - * @see UndeclaredThrowableException - * - * @author Eric Blake (ebb9@email.byu.edu) - * @since 1.3 - * @status updated to 1.4 - */ -public interface InvocationHandler -{ - /** - * When a method is invoked on a proxy instance, it is wrapped and - * this method is called instead, so that you may decide at runtime - * how the original method should behave. - * - * @param proxy the instance that the wrapped method should be - * invoked on. When this method is called by a Proxy object, - * `proxy' will be an instance of {@link Proxy}, and oddly enough, - * <code>Proxy.getInvocationHandler(proxy)</code> will return - * <code>this</code>! - * @param method the reflected method to invoke on the proxy. - * When this method is called by a Proxy object, 'method' - * will be the reflection object owned by the declaring - * class or interface, which may be a supertype of the - * interfaces the proxy directly implements. - * @param args the arguments passed to the original method, or - * <code>null</code> if the method takes no arguments. - * (But also be prepared to handle a 0-length array). - * Arguments of primitive type, such as <code>boolean</code> - * or <code>int</code>, are wrapped in the appropriate - * class such as {@link Boolean} or {@link Integer}. - * @return whatever is necessary to return from the wrapped method. - * If the wrapped method is <code>void</code>, the proxy - * instance will ignore it. If the wrapped method returns - * a primitive, this must be the correct wrapper type whose value - * is exactly assignable to the appropriate type (no widening - * will be performed); a null object in this case causes a - * {@link NullPointerException}. In all remaining cases, if - * the returned object is not assignment compatible to the - * declared type of the original method, the proxy instance - * will generate a {@link ClassCastException}. - * @throws Throwable this interface is listed as throwing anything, - * but the implementation should only throw unchecked - * exceptions and exceptions listed in the throws clause of - * all methods being overridden by the proxy instance. If - * something is thrown that is not compatible with the throws - * clause of all overridden methods, the proxy instance will - * wrap the exception in an UndeclaredThrowableException. - * Note that an exception listed in the throws clause of the - * `method' parameter might not be declared in additional - * interfaces also implemented by the proxy object. - * - * @see Proxy - * @see UndeclaredThrowableException - */ - Object invoke(Object proxy, Method method, Object[] args) - throws Throwable; - -} |