Java tutorial
/* * Copyright (c) 2005, 2019, 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 javax.annotation.processing; import java.util.Map; import java.util.Locale; import javax.lang.model.SourceVersion; import javax.lang.model.util.Elements; import javax.lang.model.util.Types; /** * An annotation processing tool framework will {@linkplain * Processor#init provide an annotation processor with an object * implementing this interface} so the processor can use facilities * provided by the framework to write new files, report error * messages, and find other utilities. * * <p>Third parties may wish to provide value-add wrappers around the * facility objects from this interface, for example a {@code Filer} * extension that allows multiple processors to coordinate writing out * a single source file. To enable this, for processors running in a * context where their side effects via the API could be visible to * each other, the tool infrastructure must provide corresponding * facility objects that are {@code .equals}, {@code Filer}s that are * {@code .equals}, and so on. In addition, the tool invocation must * be able to be configured such that from the perspective of the * running annotation processors, at least the chosen subset of helper * classes are viewed as being loaded by the same class loader. * (Since the facility objects manage shared state, the implementation * of a wrapper class must know whether or not the same base facility * object has been wrapped before.) * * @author Joseph D. Darcy * @author Scott Seligman * @author Peter von der Ahé * @since 1.6 */ public interface ProcessingEnvironment { /** * Returns the processor-specific options passed to the annotation * processing tool. Options are returned in the form of a map from * option name to option value. For an option with no value, the * corresponding value in the map is {@code null}. * * <p>See documentation of the particular tool infrastructure * being used for details on how to pass in processor-specific * options. For example, a command-line implementation may * distinguish processor-specific options by prefixing them with a * known string like {@code "-A"}; other tool implementations may * follow different conventions or provide alternative mechanisms. * A given implementation may also provide implementation-specific * ways of finding options passed to the tool in addition to the * processor-specific options. * * @return the processor-specific options passed to the tool */ Map<String, String> getOptions(); /** * Returns the messager used to report errors, warnings, and other * notices. * * @return the messager */ Messager getMessager(); /** * Returns the filer used to create new source, class, or auxiliary * files. * * @return the filer */ Filer getFiler(); /** * Returns an implementation of some utility methods for * operating on elements * * @return element utilities */ Elements getElementUtils(); /** * Returns an implementation of some utility methods for * operating on types. * * @return type utilities */ Types getTypeUtils(); /** * Returns the source version that any generated {@linkplain * Filer#createSourceFile source} and {@linkplain * Filer#createClassFile class} files should conform to. * * @return the source version to which generated source and class * files should conform to * @see Processor#getSupportedSourceVersion */ SourceVersion getSourceVersion(); /** * Returns the current locale or {@code null} if no locale is in * effect. The locale can be be used to provide localized * {@linkplain Messager messages}. * * @return the current locale or {@code null} if no locale is in * effect */ Locale getLocale(); /** * Returns {@code true} if <em>preview features</em> are enabled * and {@code false} otherwise. * @return whether or not preview features are enabled * * @implSpec The default implementation of this method returns * {@code false}. * * @since 13 */ default boolean isPreviewEnabled() { return false; } }