jakarta.ws.rs.core.Variant Maven / Gradle / Ivy
/*
* Copyright (c) 2010, 2019 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.ws.rs.core;
import java.io.StringWriter;
import java.util.List;
import java.util.Locale;
import jakarta.ws.rs.ext.RuntimeDelegate;
/**
* Abstraction for a resource representation variant.
*
* Contains information about media type, language and encoding of the resource representation.
*
* @author Paul Sandoz
* @author Marc Hadley
* @since 1.0
*/
public class Variant {
private Locale language;
private MediaType mediaType;
private String encoding;
/**
* Create a new instance of Variant.
*
* @param mediaType the media type of the variant - may be {@code null}.
* @param language the language of the variant (two-letter ISO-639 code); may be {@code null}.
* @param encoding the content encoding of the variant - may be {@code null}.
* @throws java.lang.IllegalArgumentException if all the parameters are {@code null}.
* @since 2.0
*/
public Variant(final MediaType mediaType, final String language, final String encoding) {
if (mediaType == null && language == null && encoding == null) {
throw new IllegalArgumentException("mediaType, language, encoding all null");
}
this.encoding = encoding;
this.language = (language == null) ? null : new Locale(language);
this.mediaType = mediaType;
}
/**
* Create a new instance of Variant.
*
* @param mediaType the media type of the variant - may be {@code null}.
* @param language the language of the variant (two-letter ISO-639 code); may be {@code null}.
* @param country uppercase two-letter ISO-3166 language code of the variant; may be {@code null} provided
* {@code language} is {@code null} too.
* @param encoding the content encoding of the variant - may be {@code null}.
* @throws java.lang.IllegalArgumentException if all the parameters are {@code null}.
* @since 2.0
*/
public Variant(final MediaType mediaType, final String language, final String country, final String encoding) {
if (mediaType == null && language == null && encoding == null) {
throw new IllegalArgumentException("mediaType, language, encoding all null");
}
this.encoding = encoding;
this.language = (language == null) ? null : new Locale(language, country);
this.mediaType = mediaType;
}
/**
* Create a new instance of Variant.
*
* @param mediaType the media type of the variant - may be {@code null}.
* @param language the language of the variant (two-letter ISO-639 code); may be {@code null}.
* @param country uppercase two-letter ISO-3166 language code of the variant; may be {@code null} provided
* {@code language} is {@code null} too.
* @param languageVariant vendor and browser specific language code of the variant (see also {@link Locale} class
* description); may be {@code null} provided {@code language} and {@code country} are {@code null} too.
* @param encoding the content encoding of the variant - may be {@code null}.
* @throws java.lang.IllegalArgumentException if all the parameters are {@code null}.
* @since 2.0
*/
public Variant(final MediaType mediaType, final String language, final String country, final String languageVariant, final String encoding) {
if (mediaType == null && language == null && encoding == null) {
throw new IllegalArgumentException("mediaType, language, encoding all null");
}
this.encoding = encoding;
this.language = (language == null) ? null : new Locale(language, country, languageVariant);
this.mediaType = mediaType;
}
/**
* Create a new instance of Variant.
*
* @param mediaType the media type of the variant - may be {@code null}.
* @param language the language of the variant - may be {@code null}.
* @param encoding the content encoding of the variant - may be {@code null}.
* @throws java.lang.IllegalArgumentException if all the parameters are {@code null}.
*/
public Variant(final MediaType mediaType, final Locale language, final String encoding) {
if (mediaType == null && language == null && encoding == null) {
throw new IllegalArgumentException("mediaType, language, encoding all null");
}
this.encoding = encoding;
this.language = language;
this.mediaType = mediaType;
}
/**
* Get the language of the variant.
*
* @return the language or {@code null} if none set.
*/
public Locale getLanguage() {
return language;
}
/**
* Get the string representation of the variant language, or {@code null} if no language has been set.
*
* @return the string representing variant language or {@code null} if none set.
* @since 2.0
*/
public String getLanguageString() {
return (language == null) ? null : language.toString();
}
/**
* Get the media type of the variant.
*
* @return the media type or {@code null} if none set.
*/
public MediaType getMediaType() {
return mediaType;
}
/**
* Get the encoding of the variant.
*
* @return the encoding or {@code null} if none set.
*/
public String getEncoding() {
return encoding;
}
/**
* Create a {@link VariantListBuilder} initialized with a set of supported media types.
*
* @param mediaTypes the available mediaTypes. If specific char-sets are supported they should be included as parameters
* of the respective media type.
* @return the initialized builder.
* @throws java.lang.IllegalArgumentException if mediaTypes is null or contains no elements.
*/
public static VariantListBuilder mediaTypes(final MediaType... mediaTypes) {
VariantListBuilder b = VariantListBuilder.newInstance();
b.mediaTypes(mediaTypes);
return b;
}
/**
* Create a {@link VariantListBuilder} initialized with a set of supported languages.
*
* @param languages the available languages.
* @return the initialized builder.
* @throws java.lang.IllegalArgumentException if languages is null or contains no elements.
*/
public static VariantListBuilder languages(final Locale... languages) {
VariantListBuilder b = VariantListBuilder.newInstance();
b.languages(languages);
return b;
}
/**
* Create a {@link VariantListBuilder} initialized with a set of supported encodings.
*
* @param encodings the available encodings.
* @return the initialized builder.
* @throws java.lang.IllegalArgumentException if encodings is null or contains no elements.
*/
public static VariantListBuilder encodings(final String... encodings) {
VariantListBuilder b = VariantListBuilder.newInstance();
b.encodings(encodings);
return b;
}
/**
* Generate hash code from variant properties.
*
* @return the hash code.
*/
@Override
public int hashCode() {
int hash = 7;
hash = 29 * hash + (this.language != null ? this.language.hashCode() : 0);
hash = 29 * hash + (this.mediaType != null ? this.mediaType.hashCode() : 0);
hash = 29 * hash + (this.encoding != null ? this.encoding.hashCode() : 0);
return hash;
}
/**
* Compares obj to this variant to see if they are the same considering all property values.
*
* @param obj the object to compare to.
* @return true if the two variants are the same, false otherwise.
*/
@Override
public boolean equals(final Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Variant other = (Variant) obj;
if (this.language != other.language && (this.language == null || !this.language.equals(other.language))) {
return false;
}
if (this.mediaType != other.mediaType && (this.mediaType == null || !this.mediaType.equals(other.mediaType))) {
return false;
}
// noinspection StringEquality
return this.encoding == other.encoding || (this.encoding != null && this.encoding.equals(other.encoding));
}
@Override
public String toString() {
StringWriter w = new StringWriter();
w.append("Variant[mediaType=");
w.append(mediaType == null ? "null" : mediaType.toString());
w.append(", language=");
w.append(language == null ? "null" : language.toString());
w.append(", encoding=");
w.append(encoding == null ? "null" : encoding);
w.append("]");
return w.toString();
}
/**
* A builder for a list of representation variants.
*/
public static abstract class VariantListBuilder {
/**
* Protected constructor, use the static {@code newInstance} method to obtain an instance.
*/
protected VariantListBuilder() {
}
/**
* Create a new builder instance.
*
* @return a new builder instance.
*/
public static VariantListBuilder newInstance() {
return RuntimeDelegate.getInstance().createVariantListBuilder();
}
/**
* Add the current combination of metadata to the list of supported variants (provided the current combination of
* metadata is not empty) and build a list of representation variants from the current state of the builder. After this
* method is called the builder is reset to an empty state.
*
* @return a list of representation variants.
*/
public abstract List build();
/**
* Add the current combination of metadata to the list of supported variants, after this method is called the current
* combination of metadata is emptied.
*
* If more than one value is supplied for one or more of the variant properties then a variant will be generated for
* each possible combination. E.g. in the following {@code list} would have five (4 + 1) members:
*
*
*
* List<Variant> list = VariantListBuilder.newInstance()
* .languages(Locale.ENGLISH, Locale.FRENCH).encodings("zip", "identity").add()
* .languages(Locale.GERMAN).mediaTypes(MediaType.TEXT_PLAIN_TYPE).add()
* .build()
*
*
* Note that it is not necessary to call the {@code add()} method immediately before the build method is called. E.g.
* the resulting list produced in the example above would be identical to the list produced by the following code:
*
*
*
* List<Variant> list = VariantListBuilder.newInstance()
* .languages(Locale.ENGLISH, Locale.FRENCH).encodings("zip", "identity").add()
* .languages(Locale.GERMAN).mediaTypes(MediaType.TEXT_PLAIN_TYPE)
* .build()
*
*
* @return the updated builder.
* @throws IllegalStateException if there is not at least one mediaType, language or encoding set for the current
* variant.
*/
public abstract VariantListBuilder add();
/**
* Set the language(s) for this variant.
*
* @param languages the available languages.
* @return the updated builder.
*/
public abstract VariantListBuilder languages(Locale... languages);
/**
* Set the encoding(s) for this variant.
*
* @param encodings the available encodings.
* @return the updated builder.
*/
public abstract VariantListBuilder encodings(String... encodings);
/**
* Set the media type(s) for this variant.
*
* @param mediaTypes the available mediaTypes. If specific charsets are supported they should be included as parameters
* of the respective media type.
* @return the updated builder.
*/
public abstract VariantListBuilder mediaTypes(MediaType... mediaTypes);
}
}