net.shibboleth.utilities.java.support.resolver.Resolver Maven / Gradle / Ivy

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/*
 * Licensed to the University Corporation for Advanced Internet Development,
 * Inc. (UCAID) under one or more contributor license agreements.  See the
 * NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The UCAID 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 net.shibboleth.utilities.java.support.resolver;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;

import net.shibboleth.utilities.java.support.annotation.constraint.NonnullElements;

/**
 * Generic interface for resolvers which process specified criteria and produce some implementation-specific
 * result information.
 * 
 * @param  the type of objects produced by this resolver
 * @param  the type of criteria to process during resolution
 */
public interface Resolver {

    /**
     * Process the specified criteria and return the resulting instances of the product type
     * which satisfy the criteria.
     * 
     * @param criteria the criteria to evaluate or process
     * 
     * @return instances which satisfy the criteria
     * 
     * @throws ResolverException thrown if there is an error processing the specified criteria
     */
    @Nonnull @NonnullElements Iterable resolve(@Nullable CriteriaType criteria) throws ResolverException;
    
    /**
     * Process the specified criteria and return a single instance of the product type
     * which satisfies the criteria.
     * 
     * If multiple items satisfy the criteria, the choice of which single item to 
     * return is implementation-dependent.
     * 
     * @param criteria the criteria to evaluate or process
     * 
     * @return a single instance satisfying the criteria, or null
     * 
     * @throws ResolverException thrown if there is an error processing the specified criteria
     */
    @Nullable ProductType resolveSingle(@Nullable CriteriaType criteria) throws ResolverException;
}