| /* |
| * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.reflect.generics.scope; |
| |
| import java.lang.reflect.GenericDeclaration; |
| import java.lang.reflect.TypeVariable; |
| |
| |
| /** |
| * Abstract superclass for lazy scope objects, used when building |
| * factories for generic information repositories. |
| * The type parameter {@code D} represents the type of reflective |
| * object whose scope this class is representing. |
| * <p> To subclass this, all one needs to do is implement |
| * {@code computeEnclosingScope} and the subclass' constructor. |
| */ |
| public abstract class AbstractScope<D extends GenericDeclaration> |
| implements Scope { |
| |
| private final D recvr; // the declaration whose scope this instance represents |
| |
| /** The enclosing scope of this scope. Lazily initialized. */ |
| private volatile Scope enclosingScope; |
| |
| /** |
| * Constructor. Takes a reflective object whose scope the newly |
| * constructed instance will represent. |
| * @param decl - A generic declaration whose scope the newly |
| * constructed instance will represent |
| */ |
| protected AbstractScope(D decl){ recvr = decl;} |
| |
| /** |
| * Accessor for the receiver - the object whose scope this {@code Scope} |
| * object represents. |
| * @return The object whose scope this {@code Scope} object represents |
| */ |
| protected D getRecvr() {return recvr;} |
| |
| /** This method must be implemented by any concrete subclass. |
| * It must return the enclosing scope of this scope. If this scope |
| * is a top-level scope, an instance of DummyScope must be returned. |
| * @return The enclosing scope of this scope |
| */ |
| protected abstract Scope computeEnclosingScope(); |
| |
| /** |
| * Accessor for the enclosing scope, which is computed lazily and cached. |
| * @return the enclosing scope |
| */ |
| protected Scope getEnclosingScope() { |
| Scope value = enclosingScope; |
| if (value == null) { |
| value = computeEnclosingScope(); |
| enclosingScope = value; |
| } |
| return value; |
| } |
| |
| /** |
| * Lookup a type variable in the scope, using its name. Returns null if |
| * no type variable with this name is declared in this scope or any of its |
| * surrounding scopes. |
| * @param name - the name of the type variable being looked up |
| * @return the requested type variable, if found |
| */ |
| public TypeVariable<?> lookup(String name) { |
| TypeVariable<?>[] tas = getRecvr().getTypeParameters(); |
| for (TypeVariable<?> tv : tas) { |
| if (tv.getName().equals(name)) {return tv;} |
| } |
| return getEnclosingScope().lookup(name); |
| } |
| } |