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Java example source code file (TypeVariableImpl.java)
The TypeVariableImpl.java Java example source code/* * Copyright (c) 2003, 2013, 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.annotation.*; import java.lang.reflect.AnnotatedType; import java.lang.reflect.Array; import java.lang.reflect.Constructor; import java.lang.reflect.GenericDeclaration; import java.lang.reflect.Member; import java.lang.reflect.Method; import java.lang.reflect.Type; import java.lang.reflect.TypeVariable; import java.util.LinkedHashMap; import java.util.Map; import java.util.Objects; import sun.reflect.annotation.AnnotationSupport; import sun.reflect.annotation.TypeAnnotationParser; import sun.reflect.annotation.AnnotationType; import sun.reflect.generics.factory.GenericsFactory; import sun.reflect.generics.tree.FieldTypeSignature; import sun.reflect.generics.visitor.Reifier; import sun.reflect.misc.ReflectUtil; /** * Implementation of <tt>java.lang.reflect.TypeVariable interface * for core reflection. */ public class TypeVariableImpl<D extends GenericDeclaration> extends LazyReflectiveObjectGenerator implements TypeVariable<D> { D genericDeclaration; private String name; // upper bounds - evaluated lazily private Type[] bounds; // 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[] boundASTs; // constructor is private to enforce access through static factory private TypeVariableImpl(D decl, String n, FieldTypeSignature[] bs, GenericsFactory f) { super(f); genericDeclaration = decl; name = n; boundASTs = bs; } // Accessors // accessor for ASTs for bounds. Must not be called after // bounds have been evaluated, because we might throw the ASTs // away (but that is not thread-safe, is it?) private FieldTypeSignature[] getBoundASTs() { // check that bounds were not evaluated yet assert(bounds == null); return boundASTs; } /** * Factory method. * @param decl - the reflective object that declared the type variable * that this method should create * @param name - the name of the type variable to be returned * @param bs - an array of ASTs representing the 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 type variable * @return A type variable with name, bounds, declaration and factory * specified */ public static <T extends GenericDeclaration> TypeVariableImpl<T> make(T decl, String name, FieldTypeSignature[] bs, GenericsFactory f) { if (!((decl instanceof Class) || (decl instanceof Method) || (decl instanceof Constructor))) { throw new AssertionError("Unexpected kind of GenericDeclaration" + decl.getClass().toString()); } return new TypeVariableImpl<T>(decl, name, bs, f); } /** * Returns an array of <tt>Type 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. * * <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> * * @throws <tt>TypeNotPresentException if any of the * bounds refers to a non-existent type declaration * @throws <tt>MalformedParameterizedTypeException if any of the * bounds refer to a parameterized type that cannot be instantiated * for any reason * @return an array of Types representing the upper bound(s) of this * type variable */ public Type[] getBounds() { // lazily initialize bounds if necessary if (bounds == null) { FieldTypeSignature[] fts = getBoundASTs(); // 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 bounds = ts; // could throw away bound ASTs here; thread safety? } return bounds.clone(); // return cached bounds } /** * Returns the <tt>GenericDeclaration object representing the * generic declaration that declared this type variable. * * @return the generic declaration that declared this type variable. * * @since 1.5 */ public D getGenericDeclaration(){ if (genericDeclaration instanceof Class) ReflectUtil.checkPackageAccess((Class)genericDeclaration); else if ((genericDeclaration instanceof Method) || (genericDeclaration instanceof Constructor)) ReflectUtil.conservativeCheckMemberAccess((Member)genericDeclaration); else throw new AssertionError("Unexpected kind of GenericDeclaration"); return genericDeclaration; } /** * Returns the name of this type variable, as it occurs in the source code. * * @return the name of this type variable, as it appears in the source code */ public String getName() { return name; } public String toString() {return getName();} @Override public boolean equals(Object o) { if (o instanceof TypeVariable && o.getClass() == TypeVariableImpl.class) { TypeVariable<?> that = (TypeVariable) o; GenericDeclaration thatDecl = that.getGenericDeclaration(); String thatName = that.getName(); return Objects.equals(genericDeclaration, thatDecl) && Objects.equals(name, thatName); } else return false; } @Override public int hashCode() { return genericDeclaration.hashCode() ^ name.hashCode(); } // Implementations of AnnotatedElement methods. @SuppressWarnings("unchecked") public <T extends Annotation> T getAnnotation(Class Other Java examples (source code examples)Here is a short list of links related to this Java TypeVariableImpl.java source code file: |
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