Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2009 IBM Corporation and others. * * This program and the accompanying materials * are made available under the terms of the Eclipse Public License 2.0 * which accompanies this distribution, and is available at * https://www.eclipse.org/legal/epl-2.0/ * * SPDX-License-Identifier: EPL-2.0 * * Contributors: * IBM Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jdt.core; /** * Represents a member-value pair of an annotation. * The {@link #getValue() value} is represented by an {@link Object}. To get the exact * type of this object, use its {@link #getValueKind() value kind}. If this value is an array, * {@link #getValue()} returns an instance of {@link Object}[] and the value kind returns * the kind of the elements in this array. * <p> * This interface is not intended to be implemented or extended by clients. * </p> * * @since 3.4 */ public interface IMemberValuePair { /** * Constant indicating that the value kind is an <code>int</code> represented by * an instance of {@link Integer}. */ int K_INT = 1; /** * Constant indicating that the value kind is a <code>byte</code> represented by * an instance of {@link Byte}. */ int K_BYTE = 2; /** * Constant indicating that the value kind is a <code>short</code> represented by * an instance of {@link Short}. */ int K_SHORT = 3; /** * Constant indicating that the value kind is a <code>char</code> represented by * an instance of {@link Character}. */ int K_CHAR = 4; /** * Constant indicating that the value kind is a <code>float</code> represented by * an instance of {@link Float}. */ int K_FLOAT = 5; /** * Constant indicating that the value kind is a <code>double</code> represented by * an instance of {@link Double}. */ int K_DOUBLE = 6; /** * Constant indicating that the value kind is a <code>long</code> represented by * an instance of {@link Long}. */ int K_LONG = 7; /** * Constant indicating that the value kind is a <code>boolean</code> represented by * an instance of {@link Boolean}. */ int K_BOOLEAN = 8; /** * Constant indicating that the value kind is a {@link String} represented by * the corresponding {@link String}. */ int K_STRING = 9; /** * Constant indicating that the value kind is an annotation represented by * an instance of {@link IAnnotation}. */ int K_ANNOTATION = 10; /** * Constant indicating that the value kind is a {@link Class} represented by * the name of the class (i.e. a {@link String}. If the member-value pair is coming from * a compilation unit, this is either a simple name (e.g. for <code>MyType.class</code>, * the name is "MyType"), or a qualified name (e.g. for <code>x.y.MyType.MyNestedType.class</code>, * the name is "x.y.MyType.MyNestedType"). If the member-value pair is coming from a class file, this is * always a fully qualified name. * <p> * Note that one can use {@link IType#resolveType(String)} and e.g. * {@link IJavaProject#findType(String, String, org.eclipse.core.runtime.IProgressMonitor)} * to find the corresponding {@link IType}. * </p> */ int K_CLASS = 11; /** * Constant indicating that the value is a qualified name represented by a * {@link String}. The qualified name refers to an enum constant or another * compile-time constant if the code is correct (e.g. "MyEnum.FIRST"). */ int K_QUALIFIED_NAME = 12; /** * Constant indicating that the value is a simple name represented by a * {@link String}. The simple name refers to an enum constant or another * compile-time constant if the code is correct (e.g. "FIRST" when there is * a static import for "MyEnum.FIRST"). */ int K_SIMPLE_NAME = 13; /** * Constant indicating that the value kind is unknown at this stage. The value is unknown in the * following cases: * <ul> * <li>the value is an expression that would need to be further analyzed to determine its kind. For * example, in <code>@MyAnnot(1 + 2.3)</code> the kind of the expression "1 + 2.3" is * unknown</li> * <li>the value is an array of size 0, e.g. <code>@MyAnnot({})</code></li> * <li>the value is an array that contains at least one expression that would need to be further * analyzed to determine its kind. For example, in <code>@MyAnnot({3.4, 1 + 2.3})</code>, * the kind of the second element "1 + 2.3" is unknown.</li> * <li>the value is an array that contains heterogeneous values, e.g. * <code>@MyAnnot({1, 2.3, "abc"})</code></li> * </ul> * If the value kind is unknown, the returned value is always either <code>null</code>, or an * array containing {@link Object}s and/or <code>null</code>s for unknown elements. */ int K_UNKNOWN = 14; /** * Returns the member's name of this member-value pair. * * @return the member's name of this member-value pair. */ String getMemberName(); /** * Returns the value of this member-value pair. The type of this value * is function of this member-value pair's {@link #getValueKind() value kind}. It is an * instance of {@link Object}[] if the value is an array. * <p> * If the value kind is {@link #K_UNKNOWN} and the value is not an array, then the * value is <code>null</code>. * If the value kind is {@link #K_UNKNOWN} and the value is an array, then the * value is an array containing {@link Object}s and/or <code>null</code>s for * unknown elements. * See {@link #K_UNKNOWN} for more details. * </p> * @return the value of this member-value pair. */ Object getValue(); /** * Returns the value kind of this member-value pair. This indicates the instance of * the returned {@link #getValue() value}, or the instance of the elements if the value * is an array. The value kind is one of the following constants: * {@link #K_ANNOTATION}, {@link #K_BOOLEAN}, {@link #K_BYTE}, {@link #K_CHAR}, * {@link #K_CLASS}, {@link #K_DOUBLE}, {@link #K_FLOAT}, {@link #K_INT}, {@link #K_LONG}, * {@link #K_QUALIFIED_NAME}, {@link #K_SIMPLE_NAME}, {@link #K_SHORT}, {@link #K_STRING}, * {@link #K_UNKNOWN}. * * @return the value kind of this member-value pair */ int getValueKind(); }