/* * Copyright (c) 2003, 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 <tt>D</tt> represents the type of reflective * object whose scope this class is representing. * <p> To subclass this, all one needs to do is implement * <tt>computeEnclosingScope</tt> and the subclass' constructor. */public abstract class AbstractScope<D extends GenericDeclaration>    implements Scope {     private D recvr; // the declaration whose scope this instance represents    private Scope enclosingScope; // the enclosing scope of this scope     /**     * Constructor. Takes a reflective object whose scope the newly     * constructed instance will represent.     * @param D - 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 <tt>Scope</tt>     * object represents.     * @return The object whose scope this <tt>Scope</tt> 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(){        if (enclosingScope == null) {enclosingScope = computeEnclosingScope();}        return enclosingScope;    }     /**     * 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);    }}