1 /* 2 * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.reflect.generics.repository; 27 28 import java.lang.reflect.TypeVariable; 29 import sun.reflect.generics.factory.GenericsFactory; 30 import sun.reflect.generics.tree.FormalTypeParameter; 31 import sun.reflect.generics.tree.Signature; 32 import sun.reflect.generics.visitor.Reifier; 33 34 35 36 /** 37 * This class represents the generic type information for a generic 38 * declaration. 39 * The code is not dependent on a particular reflective implementation. 40 * It is designed to be used unchanged by at least core reflection and JDI. 41 */ 42 public abstract class GenericDeclRepository<S extends Signature> 43 extends AbstractRepository<S> { 44 45 private volatile TypeVariable[] typeParams; // caches the formal type parameters 46 47 protected GenericDeclRepository(String rawSig, GenericsFactory f) { 48 super(rawSig, f); 49 } 50 51 // public API 52 /* 53 * When queried for a particular piece of type information, the 54 * general pattern is to consult the corresponding cached value. 55 * If the corresponding field is non-null, it is returned. 56 * If not, it is created lazily. This is done by selecting the appropriate 57 * part of the tree and transforming it into a reflective object 58 * using a visitor. 59 * a visitor, which is created by feeding it the factory 60 * with which the repository was created. 61 */ 62 63 /** 64 * Return the formal type parameters of this generic declaration. 65 * @return the formal type parameters of this generic declaration 66 */ 67 public TypeVariable/*<?>*/[] getTypeParameters(){ 68 TypeVariable[] typeParams = this.typeParams; 69 if (typeParams == null) { // lazily initialize type parameters 70 // first, extract type parameter subtree(s) from AST 71 FormalTypeParameter[] ftps = getTree().getFormalTypeParameters(); 72 // create array to store reified subtree(s) 73 TypeVariable[] tps = new TypeVariable[ftps.length]; 74 // reify all subtrees 75 for (int i = 0; i < ftps.length; i++) { 76 Reifier r = getReifier(); // obtain visitor 77 ftps[i].accept(r); // reify subtree 78 // extract result from visitor and store it 79 tps[i] = (TypeVariable<?>) r.getResult(); 80 } 81 typeParams = tps; // cache overall result 82 this.typeParams = typeParams; 83 } 84 return typeParams.clone(); // return cached result 85 } 86 }