jakarta.faces.convert.FacesConverter Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.faces.convert;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import jakarta.enterprise.util.AnnotationLiteral;
import jakarta.inject.Qualifier;
/**
*
* The presence of this annotation on a class automatically registers the
* class with the runtime as a {@link Converter}. The value of the {@link #value} attribute is taken to be
* converter-id, the value of the {@link #forClass} attribute is taken to be converter-for-class and
* the fully qualified class name of the class to which this annotation is attached is taken to be the
* converter-class. The implementation must guarantee that for each class annotated with
* FacesConverter, found with the algorithm in
* section 11.4 "Annotations that correspond to and may take the place of entries in the Application Configuration Resources" of the Jakarta Faces Specification Document,
* the proper variant of
* Application.addConverter() is called. If converter-id is not the empty string,
* {@link jakarta.faces.application.Application#addConverter(java.lang.String,java.lang.String)} is called, passing the
* derived converter-id as the first argument and the derived converter-class as the second argument.
* If converter-id is the empty string,
* {@link jakarta.faces.application.Application#addConverter(java.lang.Class,java.lang.String)} is called, passing the
* converter-for-class as the first argument and the derived converter-class as the second argument.
* The implementation must guarantee that all such calls to addConverter() happen during application
* startup time and before any requests are serviced.
*
*
*
*
*
* The preceding text contains an important subtlety which application users should understand. It is not possible to
* use a single {@code @FacesConverter} annotation to register a single {@code Converter} implementation both in the
* {@code
* by-class} and the {@code by-converter-id} data structures. One way to achieve this result is to put the actual
* converter logic in an abstract base class, without a {@code @FacesConverter} annotation, and derive two sub-classes,
* each with a {@code @FacesConverter} annotation. One sub-class has a {@code value} attribute but no {@code forClass}
* attribute, and the other sub-class has the converse.
*
*
*
* Please see the ViewDeclarationLanguage documentation for {@code
* } for another important subtlety regarding converters and collections.
*
*
*
*
*/
@Retention(RUNTIME)
@Target({ TYPE, FIELD, METHOD, PARAMETER })
@Inherited
@Qualifier
public @interface FacesConverter {
/**
*
* The value of this annotation attribute is taken to be the converter-id with which instances of this class of
* converter can be instantiated by calling
* {@link jakarta.faces.application.Application#createConverter(java.lang.String)}.
*
*
* @return the converter-id
*/
String value() default "";
/**
*
* The value of this annotation attribute is taken to be the converter-for-class with which instances of this
* class of converter can be instantiated by calling
* {@link jakarta.faces.application.Application#createConverter(java.lang.Class)}.
*
*
* @return the class
*/
Class forClass() default Object.class;
/**
*
* The value of this annotation attribute is taken to be an indicator that flags whether or not the given converter is a
* CDI managed converter.
*
*
* @return whether or not this converter is managed by CDI
*/
boolean managed() default false;
/**
*
* Supports inline instantiation of the {@link FacesConverter} qualifier.
*
*
* @since 4.0
*/
public static final class Literal extends AnnotationLiteral implements FacesConverter {
private static final long serialVersionUID = 1L;
/**
* Instance of the {@link FacesConverter} qualifier.
*/
public static final Literal INSTANCE = of("", Object.class, false);
private final String value;
private final Class forClass;
private final boolean managed;
public static Literal of(String value, Class forClass, boolean managed) {
return new Literal(value, forClass, managed);
}
private Literal(String value, Class forClass, boolean managed) {
this.value = value;
this.forClass = forClass;
this.managed = managed;
}
@Override
public String value() {
return value;
}
@Override
public Class forClass() {
return forClass;
}
@Override
public boolean managed() {
return managed;
}
}
}