001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
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010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.httppart;
014
015import org.apache.juneau.*;
016import org.apache.juneau.remoteable.*;
017
018/**
019 * Interface used to convert POJOs to simple strings in HTTP headers, query parameters, form-data parameters, and URI
020 * path variables.
021 * 
022 * <p>
023 * The following default implementations are provided:
024 * <ul class='doctree'>
025 *    <li class='jc'>{@link org.apache.juneau.httppart.UonPartSerializer} - Parts encoded in UON notation.
026 *    <li class='jc'>{@link org.apache.juneau.httppart.SimpleUonPartSerializer} - Parts encoded in UON notation, but
027 *       strings are treated as plain-text and arrays/collections are serialized as comma-delimited lists.
028 *    <li class='jc'>{@link org.apache.juneau.httppart.SimplePartSerializer} - Parts encoded in plain text.
029 * </ul>
030 * 
031 * <p>
032 * This class is used in the following locations:
033 * <ul>
034 *    <li class='ja'>{@link FormData#serializer()}
035 *    <li class='ja'>{@link FormDataIfNE#serializer()}
036 *    <li class='ja'>{@link Query#serializer()}
037 *    <li class='ja'>{@link QueryIfNE#serializer()}
038 *    <li class='ja'>{@link Header#serializer()}
039 *    <li class='ja'>{@link HeaderIfNE#serializer()}
040 *    <li class='ja'>{@link Path#serializer()}
041 *    <li class='ja'>{@link RequestBean#serializer()}
042 *    <li class='jc'><code>RestClientBuilder.partSerializer(Class)</code>
043 * </ul>
044 * 
045 * <p>
046 * Implementations must include either a public no-args constructor or a public constructor that takes in a single
047 * {@link PropertyStore} object.
048 */
049public interface HttpPartSerializer {
050
051   /**
052    * Represent "no" part part serializer.
053    * 
054    * <p>
055    * Used to represent the absence of a part serializer in annotations.
056    */
057   public static interface Null extends HttpPartSerializer {}
058
059   /**
060    * Converts the specified value to a string that can be used as an HTTP header value, query parameter value,
061    * form-data parameter, or URI path variable.
062    * 
063    * <p>
064    * Returned values should NOT be URL-encoded.
065    * 
066    * @param type The category of value being serialized.
067    * @param value The value being serialized.
068    * @return The serialized value.
069    */
070   public String serialize(HttpPartType type, Object value);
071}