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 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
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 *   http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing,
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 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
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 * under the License.
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 *
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package org.apache.http.protocol;

HttpContext represents execution state of an HTTP process. It is a structure
that can be used to map an attribute name to an attribute value.

The primary purpose of the HTTP context is to facilitate information sharing
among various  logically related components. HTTP context can be used
to store a processing state for one message or several consecutive messages.
Multiple logically related messages can participate in a logical session
if the same context is reused between consecutive messages.


IMPORTANT: Please note HTTP context implementation, even when thread safe,
may not be used concurrently by multiple threads, as the context may contain
thread unsafe attributes.

Since:
4.0/**
 * HttpContext represents execution state of an HTTP process. It is a structure
 * that can be used to map an attribute name to an attribute value.
 * <p>
 * The primary purpose of the HTTP context is to facilitate information sharing
 * among various  logically related components. HTTP context can be used
 * to store a processing state for one message or several consecutive messages.
 * Multiple logically related messages can participate in a logical session
 * if the same context is reused between consecutive messages.
 * </p>
 * <p>
 * IMPORTANT: Please note HTTP context implementation, even when thread safe,
 * may not be used concurrently by multiple threads, as the context may contain
 * thread unsafe attributes.
 * </p>
 *
 * @since 4.0
 */
public interface HttpContext {

    
The prefix reserved for use by HTTP components. "http." /** The prefix reserved for use by HTTP components. "http." */
    String RESERVED_PREFIX  = "http.";

    
Obtains attribute with the given name.
Params:
id – the attribute name.
Returns:
attribute value, or null if not set./**
     * Obtains attribute with the given name.
     *
     * @param id the attribute name.
     * @return attribute value, or {@code null} if not set.
     */
    Object getAttribute(String id);

    
Sets value of the attribute with the given name.
Params:
id – the attribute name.
obj – the attribute value./**
     * Sets value of the attribute with the given name.
     *
     * @param id the attribute name.
     * @param obj the attribute value.
     */
    void setAttribute(String id, Object obj);

    
Removes attribute with the given name from the context.
Params:
id – the attribute name.
Returns:
attribute value, or null if not set./**
     * Removes attribute with the given name from the context.
     *
     * @param id the attribute name.
     * @return attribute value, or {@code null} if not set.
     */
    Object removeAttribute(String id);

}