author | darcy |
Fri, 10 May 2013 12:25:16 -0700 | |
changeset 17456 | 0f2c187cd188 |
parent 5506 | 202f599c92aa |
permissions | -rw-r--r-- |
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/* |
17456
0f2c187cd188
8014357: Minor refactorings to sun.reflect.generics.reflectiveObjects.*
darcy
parents:
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diff
changeset
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* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package sun.reflect.generics.reflectiveObjects; |
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import java.lang.reflect.Type; |
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import java.lang.reflect.WildcardType; |
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import sun.reflect.generics.factory.GenericsFactory; |
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import sun.reflect.generics.tree.FieldTypeSignature; |
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import sun.reflect.generics.visitor.Reifier; |
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import java.util.Arrays; |
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/** |
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* Implementation of WildcardType interface for core reflection. |
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*/ |
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public class WildcardTypeImpl extends LazyReflectiveObjectGenerator |
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implements WildcardType { |
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// upper bounds - evaluated lazily |
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private Type[] upperBounds; |
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// lower bounds - evaluated lazily |
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private Type[] lowerBounds; |
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// The ASTs for the bounds. We are required to evaluate the bounds |
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// lazily, so we store these at least until we are first asked |
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// for the bounds. This also neatly solves the |
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// problem with F-bounds - you can't reify them before the formal |
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// is defined. |
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private FieldTypeSignature[] upperBoundASTs; |
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private FieldTypeSignature[] lowerBoundASTs; |
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// constructor is private to enforce access through static factory |
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private WildcardTypeImpl(FieldTypeSignature[] ubs, |
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FieldTypeSignature[] lbs, |
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GenericsFactory f) { |
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super(f); |
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upperBoundASTs = ubs; |
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lowerBoundASTs = lbs; |
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} |
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/** |
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* Factory method. |
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* @param ubs - an array of ASTs representing the upper bounds for the type |
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* variable to be created |
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* @param lbs - an array of ASTs representing the lower bounds for the type |
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* variable to be created |
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* @param f - a factory that can be used to manufacture reflective |
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* objects that represent the bounds of this wildcard type |
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* @return a wild card type with the requested bounds and factory |
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*/ |
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public static WildcardTypeImpl make(FieldTypeSignature[] ubs, |
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FieldTypeSignature[] lbs, |
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GenericsFactory f) { |
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return new WildcardTypeImpl(ubs, lbs, f); |
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} |
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// Accessors |
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// accessor for ASTs for upper bounds. Must not be called after upper |
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// bounds have been evaluated, because we might throw the ASTs |
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// away (but that is not thread-safe, is it?) |
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private FieldTypeSignature[] getUpperBoundASTs() { |
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// check that upper bounds were not evaluated yet |
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assert(upperBounds == null); |
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return upperBoundASTs; |
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} |
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// accessor for ASTs for lower bounds. Must not be called after lower |
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// bounds have been evaluated, because we might throw the ASTs |
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// away (but that is not thread-safe, is it?) |
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private FieldTypeSignature[] getLowerBoundASTs() { |
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// check that lower bounds were not evaluated yet |
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assert(lowerBounds == null); |
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return lowerBoundASTs; |
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} |
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/** |
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* Returns an array of <tt>Type</tt> objects representing the upper |
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* bound(s) of this type variable. Note that if no upper bound is |
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* explicitly declared, the upper bound is <tt>Object</tt>. |
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* |
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* <p>For each upper bound B : |
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* <ul> |
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* <li>if B is a parameterized type or a type variable, it is created, |
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* (see {@link #ParameterizedType} for the details of the creation |
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* process for parameterized types). |
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* <li>Otherwise, B is resolved. |
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* </ul> |
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* |
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* @return an array of Types representing the upper bound(s) of this |
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* type variable |
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* @throws <tt>TypeNotPresentException</tt> if any of the |
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* bounds refers to a non-existent type declaration |
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* @throws <tt>MalformedParameterizedTypeException</tt> if any of the |
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* bounds refer to a parameterized type that cannot be instantiated |
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* for any reason |
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*/ |
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public Type[] getUpperBounds() { |
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// lazily initialize bounds if necessary |
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if (upperBounds == null) { |
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FieldTypeSignature[] fts = getUpperBoundASTs(); // get AST |
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// allocate result array; note that |
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// keeping ts and bounds separate helps with threads |
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Type[] ts = new Type[fts.length]; |
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// iterate over bound trees, reifying each in turn |
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for ( int j = 0; j < fts.length; j++) { |
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Reifier r = getReifier(); |
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fts[j].accept(r); |
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ts[j] = r.getResult(); |
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} |
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// cache result |
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upperBounds = ts; |
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// could throw away upper bound ASTs here; thread safety? |
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} |
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return upperBounds.clone(); // return cached bounds |
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} |
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/** |
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* Returns an array of <tt>Type</tt> objects representing the |
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* lower bound(s) of this type variable. Note that if no lower bound is |
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* explicitly declared, the lower bound is the type of <tt>null</tt>. |
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* In this case, a zero length array is returned. |
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* |
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* <p>For each lower bound B : |
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* <ul> |
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* <li>if B is a parameterized type or a type variable, it is created, |
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* (see {@link #ParameterizedType} for the details of the creation |
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* process for parameterized types). |
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* <li>Otherwise, B is resolved. |
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* </ul> |
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* |
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* @return an array of Types representing the lower bound(s) of this |
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* type variable |
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* @throws <tt>TypeNotPresentException</tt> if any of the |
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* bounds refers to a non-existent type declaration |
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* @throws <tt>MalformedParameterizedTypeException</tt> if any of the |
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* bounds refer to a parameterized type that cannot be instantiated |
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* for any reason |
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*/ |
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public Type[] getLowerBounds() { |
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// lazily initialize bounds if necessary |
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if (lowerBounds == null) { |
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FieldTypeSignature[] fts = getLowerBoundASTs(); // get AST |
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// allocate result array; note that |
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// keeping ts and bounds separate helps with threads |
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Type[] ts = new Type[fts.length]; |
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// iterate over bound trees, reifying each in turn |
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for ( int j = 0; j < fts.length; j++) { |
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Reifier r = getReifier(); |
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fts[j].accept(r); |
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ts[j] = r.getResult(); |
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} |
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// cache result |
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lowerBounds = ts; |
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// could throw away lower bound ASTs here; thread safety? |
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} |
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return lowerBounds.clone(); // return cached bounds |
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} |
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public String toString() { |
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Type[] lowerBounds = getLowerBounds(); |
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Type[] bounds = lowerBounds; |
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StringBuilder sb = new StringBuilder(); |
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if (lowerBounds.length > 0) |
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sb.append("? super "); |
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else { |
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Type[] upperBounds = getUpperBounds(); |
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if (upperBounds.length > 0 && !upperBounds[0].equals(Object.class) ) { |
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bounds = upperBounds; |
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sb.append("? extends "); |
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} else |
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return "?"; |
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} |
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assert bounds.length > 0; |
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boolean first = true; |
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for(Type bound: bounds) { |
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if (!first) |
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sb.append(" & "); |
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first = false; |
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17456
0f2c187cd188
8014357: Minor refactorings to sun.reflect.generics.reflectiveObjects.*
darcy
parents:
5506
diff
changeset
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sb.append(bound.getTypeName()); |
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} |
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return sb.toString(); |
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} |
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@Override |
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public boolean equals(Object o) { |
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if (o instanceof WildcardType) { |
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WildcardType that = (WildcardType) o; |
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return |
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Arrays.equals(this.getLowerBounds(), |
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that.getLowerBounds()) && |
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Arrays.equals(this.getUpperBounds(), |
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that.getUpperBounds()); |
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} else |
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return false; |
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} |
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@Override |
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public int hashCode() { |
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Type [] lowerBounds = getLowerBounds(); |
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Type [] upperBounds = getUpperBounds(); |
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return Arrays.hashCode(lowerBounds) ^ Arrays.hashCode(upperBounds); |
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} |
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} |