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 * 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */

package org.apache.http.params;

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

import org.apache.http.util.Args;

HttpParams implementation that delegates resolution of a parameter to the given default HttpParams instance if the parameter is not present in the local one. The state of the local collection can be mutated, whereas the default collection is treated as read-only. 
Since:
4.0
Deprecated:
(4.3) use configuration classes provided 'org.apache.http.config'
 and 'org.apache.http.client.config'/**
 * {@link HttpParams} implementation that delegates resolution of a parameter
 * to the given default {@link HttpParams} instance if the parameter is not
 * present in the local one. The state of the local collection can be mutated,
 * whereas the default collection is treated as read-only.
 *
 * @since 4.0
 *
 * @deprecated (4.3) use configuration classes provided 'org.apache.http.config'
 *  and 'org.apache.http.client.config'
 */
@Deprecated
public final class DefaultedHttpParams extends AbstractHttpParams {

    private final HttpParams local;
    private final HttpParams defaults;

    
Create the defaulted set of HttpParams.
Params:
local – the mutable set of HttpParams
defaults – the default set of HttpParams, not mutated by this class/**
     * Create the defaulted set of HttpParams.
     *
     * @param local the mutable set of HttpParams
     * @param defaults the default set of HttpParams, not mutated by this class
     */
    public DefaultedHttpParams(final HttpParams local, final HttpParams defaults) {
        super();
        this.local = Args.notNull(local, "Local HTTP parameters");
        this.defaults = defaults;
    }

    
Creates a copy of the local collection with the same default
/**
     * Creates a copy of the local collection with the same default
     */
    @Override
    public HttpParams copy() {
        final HttpParams clone = this.local.copy();
        return new DefaultedHttpParams(clone, this.defaults);
    }

    
Retrieves the value of the parameter from the local collection and, if the
parameter is not set locally, delegates its resolution to the default
collection.
/**
     * Retrieves the value of the parameter from the local collection and, if the
     * parameter is not set locally, delegates its resolution to the default
     * collection.
     */
    @Override
    public Object getParameter(final String name) {
        Object obj = this.local.getParameter(name);
        if (obj == null && this.defaults != null) {
            obj = this.defaults.getParameter(name);
        }
        return obj;
    }

    
Attempts to remove the parameter from the local collection. This method
does not modify the default collection.
/**
     * Attempts to remove the parameter from the local collection. This method
     * <i>does not</i> modify the default collection.
     */
    @Override
    public boolean removeParameter(final String name) {
        return this.local.removeParameter(name);
    }

    
Sets the parameter in the local collection. This method does not
modify the default collection.
/**
     * Sets the parameter in the local collection. This method <i>does not</i>
     * modify the default collection.
     */
    @Override
    public HttpParams setParameter(final String name, final Object value) {
        return this.local.setParameter(name, value);
    }

    
Returns:
the default HttpParams collection/**
     *
     * @return the default HttpParams collection
     */
    public HttpParams getDefaults() {
        return this.defaults;
    }

    
Returns the current set of names
from both the local and default HttpParams instances.
Changes to the underlying HttpParams intances are not reflected
in the set - it is a snapshot.
Throws:
UnsupportedOperationException – if either the local or default HttpParams instances do not implement HttpParamsNames
Returns:
the combined set of names, as a Set<String>
Since:
4.2/**
     * Returns the current set of names
     * from both the local and default HttpParams instances.
     *
     * Changes to the underlying HttpParams intances are not reflected
     * in the set - it is a snapshot.
     *
     * @return the combined set of names, as a Set&lt;String&gt;
     * @since 4.2
     * @throws UnsupportedOperationException if either the local or default HttpParams instances do not implement HttpParamsNames
     */
    @Override
    public Set<String> getNames() {
        final Set<String> combined = new HashSet<String>(getNames(defaults));
        combined.addAll(getNames(this.local));
        return combined ;
    }

    
Returns the current set of defaults names.
Changes to the underlying HttpParams are not reflected
in the set - it is a snapshot.
Throws:
UnsupportedOperationException – if the default HttpParams instance does not implement HttpParamsNames
Returns:
the names, as a Set<String>
Since:
4.2/**
     * Returns the current set of defaults names.
     *
     * Changes to the underlying HttpParams are not reflected
     * in the set - it is a snapshot.
     *
     * @return the names, as a Set&lt;String&gt;
     * @since 4.2
     * @throws UnsupportedOperationException if the default HttpParams instance does not implement HttpParamsNames
     */
    public Set<String> getDefaultNames() {
        return new HashSet<String>(getNames(this.defaults));
    }

    
Returns the current set of local names.
Changes to the underlying HttpParams are not reflected
in the set - it is a snapshot.
Throws:
UnsupportedOperationException – if the local HttpParams instance does not implement HttpParamsNames
Returns:
the names, as a Set<String>
Since:
4.2/**
     * Returns the current set of local names.
     *
     * Changes to the underlying HttpParams are not reflected
     * in the set - it is a snapshot.
     *
     * @return the names, as a Set&lt;String&gt;
     * @since 4.2
     * @throws UnsupportedOperationException if the local HttpParams instance does not implement HttpParamsNames
     */
    public Set<String> getLocalNames() {
        return new HashSet<String>(getNames(this.local));
    }

    // Helper method
    private Set<String> getNames(final HttpParams params) {
        if (params instanceof HttpParamsNames) {
            return ((HttpParamsNames) params).getNames();
        }
        throw new UnsupportedOperationException("HttpParams instance does not implement HttpParamsNames");
    }

}