| /* |
| * Copyright (c) 2003, 2004, 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.reflectiveObjects; |
| |
| |
| import java.lang.reflect.Type; |
| import java.lang.reflect.WildcardType; |
| import sun.reflect.generics.factory.GenericsFactory; |
| import sun.reflect.generics.tree.FieldTypeSignature; |
| import sun.reflect.generics.visitor.Reifier; |
| import java.util.Arrays; |
| |
| |
| /** |
| * Implementation of WildcardType interface for core reflection. |
| */ |
| public class WildcardTypeImpl extends LazyReflectiveObjectGenerator |
| implements WildcardType { |
| // upper bounds - evaluated lazily |
| private Type[] upperBounds; |
| // lower bounds - evaluated lazily |
| private Type[] lowerBounds; |
| // The ASTs for the bounds. We are required to evaluate the bounds |
| // lazily, so we store these at least until we are first asked |
| // for the bounds. This also neatly solves the |
| // problem with F-bounds - you can't reify them before the formal |
| // is defined. |
| private FieldTypeSignature[] upperBoundASTs; |
| private FieldTypeSignature[] lowerBoundASTs; |
| |
| // constructor is private to enforce access through static factory |
| private WildcardTypeImpl(FieldTypeSignature[] ubs, |
| FieldTypeSignature[] lbs, |
| GenericsFactory f) { |
| super(f); |
| upperBoundASTs = ubs; |
| lowerBoundASTs = lbs; |
| } |
| |
| /** |
| * Factory method. |
| * @param ubs - an array of ASTs representing the upper bounds for the type |
| * variable to be created |
| * @param lbs - an array of ASTs representing the lower bounds for the type |
| * variable to be created |
| * @param f - a factory that can be used to manufacture reflective |
| * objects that represent the bounds of this wildcard type |
| * @return a wild card type with the requested bounds and factory |
| */ |
| public static WildcardTypeImpl make(FieldTypeSignature[] ubs, |
| FieldTypeSignature[] lbs, |
| GenericsFactory f) { |
| return new WildcardTypeImpl(ubs, lbs, f); |
| } |
| |
| // Accessors |
| |
| // accessor for ASTs for upper bounds. Must not be called after upper |
| // bounds have been evaluated, because we might throw the ASTs |
| // away (but that is not thread-safe, is it?) |
| private FieldTypeSignature[] getUpperBoundASTs() { |
| // check that upper bounds were not evaluated yet |
| assert(upperBounds == null); |
| return upperBoundASTs; |
| } |
| // accessor for ASTs for lower bounds. Must not be called after lower |
| // bounds have been evaluated, because we might throw the ASTs |
| // away (but that is not thread-safe, is it?) |
| private FieldTypeSignature[] getLowerBoundASTs() { |
| // check that lower bounds were not evaluated yet |
| assert(lowerBounds == null); |
| return lowerBoundASTs; |
| } |
| |
| /** |
| * Returns an array of <tt>Type</tt> objects representing the upper |
| * bound(s) of this type variable. Note that if no upper bound is |
| * explicitly declared, the upper bound is <tt>Object</tt>. |
| * |
| * <p>For each upper bound B : |
| * <ul> |
| * <li>if B is a parameterized type or a type variable, it is created, |
| * (see {@link #ParameterizedType} for the details of the creation |
| * process for parameterized types). |
| * <li>Otherwise, B is resolved. |
| * </ul> |
| * |
| * @return an array of Types representing the upper bound(s) of this |
| * type variable |
| * @throws <tt>TypeNotPresentException</tt> if any of the |
| * bounds refers to a non-existent type declaration |
| * @throws <tt>MalformedParameterizedTypeException</tt> if any of the |
| * bounds refer to a parameterized type that cannot be instantiated |
| * for any reason |
| */ |
| public Type[] getUpperBounds() { |
| // lazily initialize bounds if necessary |
| if (upperBounds == null) { |
| FieldTypeSignature[] fts = getUpperBoundASTs(); // get AST |
| |
| // allocate result array; note that |
| // keeping ts and bounds separate helps with threads |
| Type[] ts = new Type[fts.length]; |
| // iterate over bound trees, reifying each in turn |
| for ( int j = 0; j < fts.length; j++) { |
| Reifier r = getReifier(); |
| fts[j].accept(r); |
| ts[j] = r.getResult(); |
| } |
| // cache result |
| upperBounds = ts; |
| // could throw away upper bound ASTs here; thread safety? |
| } |
| return upperBounds.clone(); // return cached bounds |
| } |
| |
| /** |
| * Returns an array of <tt>Type</tt> objects representing the |
| * lower bound(s) of this type variable. Note that if no lower bound is |
| * explicitly declared, the lower bound is the type of <tt>null</tt>. |
| * In this case, a zero length array is returned. |
| * |
| * <p>For each lower bound B : |
| * <ul> |
| * <li>if B is a parameterized type or a type variable, it is created, |
| * (see {@link #ParameterizedType} for the details of the creation |
| * process for parameterized types). |
| * <li>Otherwise, B is resolved. |
| * </ul> |
| * |
| * @return an array of Types representing the lower bound(s) of this |
| * type variable |
| * @throws <tt>TypeNotPresentException</tt> if any of the |
| * bounds refers to a non-existent type declaration |
| * @throws <tt>MalformedParameterizedTypeException</tt> if any of the |
| * bounds refer to a parameterized type that cannot be instantiated |
| * for any reason |
| */ |
| public Type[] getLowerBounds() { |
| // lazily initialize bounds if necessary |
| if (lowerBounds == null) { |
| FieldTypeSignature[] fts = getLowerBoundASTs(); // get AST |
| // allocate result array; note that |
| // keeping ts and bounds separate helps with threads |
| Type[] ts = new Type[fts.length]; |
| // iterate over bound trees, reifying each in turn |
| for ( int j = 0; j < fts.length; j++) { |
| Reifier r = getReifier(); |
| fts[j].accept(r); |
| ts[j] = r.getResult(); |
| } |
| // cache result |
| lowerBounds = ts; |
| // could throw away lower bound ASTs here; thread safety? |
| } |
| return lowerBounds.clone(); // return cached bounds |
| } |
| |
| public String toString() { |
| Type[] lowerBounds = getLowerBounds(); |
| Type[] bounds = lowerBounds; |
| StringBuilder sb = new StringBuilder(); |
| |
| if (lowerBounds.length > 0) |
| sb.append("? super "); |
| else { |
| Type[] upperBounds = getUpperBounds(); |
| if (upperBounds.length > 0 && !upperBounds[0].equals(Object.class) ) { |
| bounds = upperBounds; |
| sb.append("? extends "); |
| } else |
| return "?"; |
| } |
| |
| assert bounds.length > 0; |
| |
| boolean first = true; |
| for(Type bound: bounds) { |
| if (!first) |
| sb.append(" & "); |
| |
| first = false; |
| if (bound instanceof Class) |
| sb.append(((Class)bound).getName() ); |
| else |
| sb.append(bound.toString()); |
| } |
| return sb.toString(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (o instanceof WildcardType) { |
| WildcardType that = (WildcardType) o; |
| return |
| Arrays.equals(this.getLowerBounds(), |
| that.getLowerBounds()) && |
| Arrays.equals(this.getUpperBounds(), |
| that.getUpperBounds()); |
| } else |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| Type [] lowerBounds = getLowerBounds(); |
| Type [] upperBounds = getUpperBounds(); |
| |
| return Arrays.hashCode(lowerBounds) ^ Arrays.hashCode(upperBounds); |
| } |
| } |