Java tutorial
/* * Copyright (c) 2003, 2015, 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 java.lang.reflect; /** * WildcardType represents a wildcard type expression, such as * {@code ?}, {@code ? extends Number}, or {@code ? super Integer}. * * @since 1.5 */ public interface WildcardType extends Type { /** * Returns an array of {@code Type} objects representing the upper * bound(s) of this type variable. If no upper bound is * explicitly declared, the upper bound is {@code Object}. * * <p>For each upper bound B : * <ul> * <li>if B is a parameterized type or a type variable, it is created, * (see {@link java.lang.reflect.ParameterizedType 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 TypeNotPresentException if any of the * bounds refers to a non-existent type declaration * @throws MalformedParameterizedTypeException if any of the * bounds refer to a parameterized type that cannot be instantiated * for any reason */ Type[] getUpperBounds(); /** * Returns an array of {@code Type} objects representing the * lower bound(s) of this type variable. If no lower bound is * explicitly declared, the lower bound is the type of {@code null}. * 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 java.lang.reflect.ParameterizedType 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 TypeNotPresentException if any of the * bounds refers to a non-existent type declaration * @throws MalformedParameterizedTypeException if any of the * bounds refer to a parameterized type that cannot be instantiated * for any reason */ Type[] getLowerBounds(); // one or many? Up to language spec; currently only one, but this API // allows for generalization. }