maven-core/src/main/java/org/apache/maven/artifact/resolver/filter/CumulativeScopeArtifactFilter.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.artifact.resolver.filter;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

/**
 * Filter to only retain objects in the given scope or better. This implementation allows the accumulation of multiple
 * scopes and their associated implied scopes, so that the user can filter apply a series of implication rules in a
 * single step. This should be a more efficient implementation of multiple standard {@link ScopeArtifactFilter}
 * instances ORed together.
 *
 */
public class CumulativeScopeArtifactFilter extends AbstractScopeArtifactFilter {

    private Set<String> scopes;

    /**
     * Create a new filter with the specified scopes and their implied scopes enabled.
     *
     * @param scopes The scopes to enable, along with all implied scopes, may be {@code null}.
     */
    public CumulativeScopeArtifactFilter(Collection<String> scopes) {
        this.scopes = new HashSet<>();

        addScopes(scopes);
    }

    /**
     * Creates a new filter that combines the specified filters.
     *
     * @param filters The filters to combine, may be {@code null}.
     */
    public CumulativeScopeArtifactFilter(CumulativeScopeArtifactFilter... filters) {
        this.scopes = new HashSet<>();

        if (filters != null) {
            for (CumulativeScopeArtifactFilter filter : filters) {
                addScopes(filter.getScopes());
            }
        }
    }

    private void addScopes(Collection<String> scopes) {
        if (scopes != null) {
            for (String scope : scopes) {
                addScope(scope);
            }
        }
    }

    private void addScope(String scope) {
        this.scopes.add(scope);

        addScopeInternal(scope);
    }

    public Set<String> getScopes() {
        return scopes;
    }

    @Override
    public int hashCode() {
        int hash = 17;

        hash = hash * 31 + scopes.hashCode();

        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }

        if (!(obj instanceof CumulativeScopeArtifactFilter)) {
            return false;
        }

        CumulativeScopeArtifactFilter that = (CumulativeScopeArtifactFilter) obj;

        return scopes.equals(that.scopes);
    }
}