ExtensibleEnums.java
/*
* 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 org.apache.maven.api;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.Objects;
import java.util.Set;
/**
* Utility class for creating extensible enum implementations.
* This class provides factory methods for creating instances of extensible enums
* such as Language, PathScope, and ProjectScope.
*
* @since 4.0.0
*/
abstract class ExtensibleEnums {
/**
* Creates a new Language instance with the specified ID.
*
* @param id the identifier for the language
* @return a new Language instance
*/
static Language language(String id) {
return new DefaultLanguage(id);
}
/**
* Creates a new PathScope instance with the specified ID, project scope, and dependency scopes.
*
* @param id the identifier for the path scope
* @param projectScope the project scope associated with this path scope
* @param dependencyScopes the dependency scopes associated with this path scope
* @return a new PathScope instance
*/
static PathScope pathScope(String id, ProjectScope projectScope, DependencyScope... dependencyScopes) {
return new DefaultPathScope(id, projectScope, dependencyScopes);
}
/**
* Creates a new ProjectScope instance with the specified ID.
*
* @param id the identifier for the project scope
* @return a new ProjectScope instance
*/
static ProjectScope projectScope(String id) {
return new DefaultProjectScope(id);
}
/**
* Base implementation of the ExtensibleEnum interface.
* Provides common functionality for all extensible enum implementations.
*/
private static class DefaultExtensibleEnum implements ExtensibleEnum {
private final String id;
/**
* Creates a new DefaultExtensibleEnum with the specified ID.
*
* @param id the identifier for this enum value, must not be null
*/
DefaultExtensibleEnum(String id) {
this.id = Objects.requireNonNull(id);
}
/**
* Returns the identifier for this enum value.
*
* @return the identifier
*/
@Override
public String id() {
return id;
}
@Override
public int hashCode() {
return id().hashCode();
}
@Override
public boolean equals(Object obj) {
return obj != null && getClass() == obj.getClass() && id().equals(((DefaultExtensibleEnum) obj).id());
}
@Override
public String toString() {
return getClass().getSimpleName() + "[" + id() + "]";
}
}
/**
* Implementation of the PathScope interface.
*/
private static class DefaultPathScope extends DefaultExtensibleEnum implements PathScope {
private final ProjectScope projectScope;
private final Set<DependencyScope> dependencyScopes;
/**
* Creates a new DefaultPathScope with the specified ID, project scope, and dependency scopes.
*
* @param id the identifier for this path scope
* @param projectScope the project scope associated with this path scope, must not be null
* @param dependencyScopes the dependency scopes associated with this path scope, must not be null
*/
DefaultPathScope(String id, ProjectScope projectScope, DependencyScope... dependencyScopes) {
super(id);
this.projectScope = Objects.requireNonNull(projectScope);
this.dependencyScopes =
Collections.unmodifiableSet(new HashSet<>(Arrays.asList(Objects.requireNonNull(dependencyScopes))));
}
/**
* Returns the project scope associated with this path scope.
*
* @return the project scope
*/
@Override
public ProjectScope projectScope() {
return projectScope;
}
/**
* Returns the dependency scopes associated with this path scope.
*
* @return an unmodifiable set of dependency scopes
*/
@Override
public Set<DependencyScope> dependencyScopes() {
return dependencyScopes;
}
}
/**
* Implementation of the ProjectScope interface.
*/
private static class DefaultProjectScope extends DefaultExtensibleEnum implements ProjectScope {
/**
* Creates a new DefaultProjectScope with the specified ID.
*
* @param id the identifier for this project scope
*/
DefaultProjectScope(String id) {
super(id);
}
}
/**
* Implementation of the Language interface.
*/
private static class DefaultLanguage extends DefaultExtensibleEnum implements Language {
/**
* Creates a new DefaultLanguage with the specified ID.
*
* @param id the identifier for this language
*/
DefaultLanguage(String id) {
super(id);
}
}
}