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// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
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.http.part;
014
015import static org.apache.juneau.common.internal.StringUtils.*;
016import static org.apache.juneau.internal.CollectionUtils.*;
017
018import java.util.*;
019import java.util.function.*;
020
021import org.apache.http.*;
022import org.apache.juneau.assertions.*;
023
024/**
025 * A {@link NameValuePair} that consists of a single string value.
026 *
027 * <h5 class='section'>See Also:</h5><ul>
028 *    <li class='link'><a class="doclink" href="../../../../../index.html#juneau-rest-common">juneau-rest-common</a>
029 * </ul>
030 */
031public class BasicStringPart extends BasicPart {
032
033   //-----------------------------------------------------------------------------------------------------------------
034   // Static
035   //-----------------------------------------------------------------------------------------------------------------
036
037   /**
038    * Static creator.
039    *
040    * @param name The part name.
041    * @param value The part value.
042    * @return A new {@link BasicStringPart} object, or <jk>null</jk> if the name or value is <jk>null</jk>.
043    */
044   public static BasicStringPart of(String name, String value) {
045      if (isEmpty(name) || value == null)
046         return null;
047      return new BasicStringPart(name, value);
048   }
049
050   /**
051    * Static creator with delayed value.
052    *
053    * <p>
054    * Part value is re-evaluated on each call to {@link NameValuePair#getValue()}.
055    *
056    * @param name The part name.
057    * @param value The part value supplier.
058    * @return A new {@link BasicStringPart} object, or <jk>null</jk> if the name or supplier is <jk>null</jk>.
059    */
060   public static BasicStringPart of(String name, Supplier<String> value) {
061      if (isEmpty(name) || value == null)
062         return null;
063      return new BasicStringPart(name, value);
064   }
065
066   //-----------------------------------------------------------------------------------------------------------------
067   // Instance
068   //-----------------------------------------------------------------------------------------------------------------
069
070   private final String value;
071   private final Supplier<String> supplier;
072
073   /**
074    * Constructor.
075    *
076    * @param name The part name.  Must not be <jk>null</jk>.
077    * @param value The part value.  Can be <jk>null</jk>.
078    */
079   public BasicStringPart(String name, String value) {
080      super(name, value);
081      this.value = value;
082      this.supplier = null;
083   }
084
085   /**
086    * Constructor.
087    *
088    * @param name The part name.  Must not be <jk>null</jk>.
089    * @param value The part value supplier.  Can be <jk>null</jk> or supply <jk>null</jk>.
090    */
091   public BasicStringPart(String name, Supplier<String> value) {
092      super(name, value);
093      this.value = null;
094      this.supplier = value;
095   }
096
097   /**
098    * Provides the ability to perform fluent-style assertions on this part.
099    *
100    * @return A new fluent assertion object.
101    * @throws AssertionError If assertion failed.
102    */
103   public FluentStringAssertion<BasicStringPart> assertString() {
104      return new FluentStringAssertion<>(value(), this);
105   }
106
107   @Override /* Header */
108   public String getValue() {
109      return value();
110   }
111
112   /**
113    * Returns The part value as a {@link String} wrapped in an {@link Optional}.
114    *
115    * @return The part value as a {@link String} wrapped in an {@link Optional}.  Never <jk>null</jk>.
116    */
117   public Optional<String> asString() {
118      return optional(value());
119   }
120
121   /**
122    * Return the value if present, otherwise return <c>other</c>.
123    *
124    * <p>
125    * This is a shortened form for calling <c>asString().orElse(<jv>other</jv>)</c>.
126    *
127    * @param other The value to be returned if there is no value present, can be <jk>null</jk>.
128    * @return The value, if present, otherwise <c>other</c>.
129    */
130   public String orElse(String other) {
131      String x = value();
132      return x != null ? x : other;
133   }
134
135   private String value() {
136      if (supplier != null)
137         return supplier.get();
138      return value;
139   }
140}