groovy.transform.ExternalizeMethods Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package groovy.transform;
import org.codehaus.groovy.transform.GroovyASTTransformationClass;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Class annotation used to assist in the creation of {@code Externalizable} classes.
* The {@code @ExternalizeMethods} annotation instructs the compiler to execute an
* AST transformation which adds {@code writeExternal()} and {@code readExternal()} methods
* to a class and adds {@code Externalizable} to the interfaces which the class implements.
* The {@code writeExternal()} method writes each property (and optionally field) of the class
* while the {@code readExternal()} method will read each one back in the same order.
* Properties or fields marked as {@code transient} are ignored.
* This annotation is typically used in conjunction with the {@code @ExternalizeMethods} annotation but
* most usually not directly but rather via {@code @AutoExternalizable} which is a shortcut for both annotations.
*
* Example usage:
*
* import groovy.transform.*
* {@code @ExternalizeMethods}
* class Person {
* String first, last
* List favItems
* Date since
* }
*
* Which will create a class of the following form:
*
* class Person implements Externalizable {
* ...
* public void writeExternal(ObjectOutput out) throws IOException {
* out.writeObject(first)
* out.writeObject(last)
* out.writeObject(favItems)
* out.writeObject(since)
* }
*
* public void readExternal(ObjectInput oin) {
* first = (String) oin.readObject()
* last = (String) oin.readObject()
* favItems = (List) oin.readObject()
* since = (Date) oin.readObject()
* }
* ...
* }
*
*
* @author Paul King
* @since 1.8.0
*/
@java.lang.annotation.Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE})
@GroovyASTTransformationClass("org.codehaus.groovy.transform.ExternalizeMethodsASTTransformation")
public @interface ExternalizeMethods {
/**
* Comma separated list of property names to exclude from externalizing.
* For convenience, a String with comma separated names
* can be used in addition to an array (using Groovy's literal list notation) of String values.
*/
String[] excludes() default {};
/**
* Include fields as well as properties when externalizing.
*/
boolean includeFields() default false;
}