/*
 * Copyright 2012-2016 Credit Suisse
 * Copyright 2018-2020 Werner Keil, Otavio Santana, Trivadis AG
 *
 * Licensed 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 javax.money;

import java.util.Collections;
import java.util.List;

Represents a general context of data targeting an item of type Q. Contexts are used to add arbitrary data that cannot be be mapped in a standard way to the money API, e.g. use case or customer specific extensions or specialities.

Superclasses of this class must be final, immutable, serializable and thread-safe.
/**
 * Represents a general context of data targeting an item of type {@code Q}. Contexts are used to add arbitrary
 * data that cannot be be mapped in a standard way to the money API, e.g. use case or customer specific
 * extensions or specialities.<p>
 * Superclasses of this class must be final, immutable, serializable and thread-safe.
 */
public abstract class AbstractQuery extends AbstractContext {

	private static final long serialVersionUID = 5309190820845869327L;

	
Key for storing the target providers to be queried
/**
     * Key for storing the target providers to be queried
     */
    protected static final String KEY_QUERY_PROVIDERS = "Query.providers";

    
Key name for the timestamp attribute.
/**
     * Key name for the timestamp attribute.
     */
    protected static final String KEY_QUERY_TIMESTAMP = "Query.timestamp";

    
Key name for the target type attribute.
/**
     * Key name for the target type attribute.
     */
    protected static final String KEY_QUERY_TARGET_TYPE = "Query.targetType";


    
Constructor, using a builder.
Params:
builder – the builder, not null./**
     * Constructor, using a builder.
     *
     * @param builder the builder, not null.
     */
    protected AbstractQuery(@SuppressWarnings("rawtypes") AbstractQueryBuilder builder) {
        super(builder);
    }

    
Returns the providers and their ordering to be considered. This information typically must be interpreted by the singleton SPI implementations, which are backing the singleton accessors. If the list returned is empty, the default provider list, determined by methods like getDefaultProviderNames() should be used. 
Returns:
the ordered providers, never null./**
     * Returns the providers and their ordering to be considered. This information typically must be interpreted by the
     * singleton SPI implementations, which are backing the singleton accessors.
     * If the list returned is empty, the default provider list,
     * determined by methods like {@code getDefaultProviderNames()} should be used.
     *
     * @return the ordered providers, never null.
     */
    public List<String> getProviderNames() {

        @SuppressWarnings("unchecked") List<String> result = get(KEY_QUERY_PROVIDERS, List.class);
        if (result == null) {
            return Collections.emptyList();
        }
        return result;
    }

    
Gets the target implementation type required. This can be used to explicitly acquire a specific implementation
type and use a query to configure the instance or factory to be returned.
Returns:
this Builder for chaining./**
     * Gets the target implementation type required. This can be used to explicitly acquire a specific implementation
     * type and use a query to configure the instance or factory to be returned.
     *
     * @return this Builder for chaining.
     */
    public Class<?> getTargetType() {
        return get(KEY_QUERY_TARGET_TYPE, Class.class);
    }

}