/hudson-core/src/main/java/hudson/Extension.java
http://github.com/hudson/hudson · Java · 87 lines · 15 code · 5 blank · 67 comment · 0 complexity · 62440939ff118c1b5280254765061bd3 MD5 · raw file
- /*
- * The MIT License
- *
- * Copyright (c) 2004-2010, Sun Microsystems, Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
- package hudson;
- import net.java.sezpoz.Indexable;
- import java.lang.annotation.Documented;
- import java.lang.annotation.Retention;
- import java.lang.annotation.Target;
- import static java.lang.annotation.ElementType.*;
- import static java.lang.annotation.RetentionPolicy.RUNTIME;
- /**
- * Marks a field, a method, or a class for automatic discovery, so that Hudson can locate
- * implementations of {@link ExtensionPoint}s automatically.
- *
- * <p>
- * (In contrast, in earlier Hudson, the registration was manual.)
- *
- * <p>
- * In a simplest case, put this on your class, and Hudson will create an instance of it
- * and register it to the appropriate {@link ExtensionList}.
- *
- * <p>
- * If you'd like Hudson to call
- * a factory method instead of a constructor, put this annotation on your static factory
- * method. Hudson will invoke it and if the method returns a non-null instance, it'll be
- * registered. The return type of the method is used to determine which {@link ExtensionList}
- * will get the instance.
- *
- * Finally, you can put this annotation on a static field if the field contains a reference
- * to an instance that you'd like to register.
- *
- * <p>
- * This is the default way of having your implementations auto-registered to Hudson,
- * but Hudson also supports arbitrary DI containers for hosting your implementations.
- * See {@link ExtensionFinder} for more details.
- *
- * @author Kohsuke Kawaguchi
- * @since 1.286
- * @see <a href="http://java.net/projects/sezpoz/">SezPoz</a>
- * @see ExtensionFinder
- * @see ExtensionList
- */
- @Indexable
- @Retention(RUNTIME)
- @Target({TYPE, FIELD, METHOD})
- @Documented
- public @interface Extension {
- /**
- * Used for sorting extensions.
- *
- * Extensions will be sorted in the descending order of the ordinal.
- * This is a rather poor approach to the problem, so its use is generally discouraged.
- *
- * @since 1.306
- */
- double ordinal() default 0;
- /**
- * If an extension is optional, don't log any class loading errors when reading it.
- * @since 1.358
- */
- boolean optional() default false;
- }