001/*
002 * Copyright 2015-2016 UnboundID Corp.
003 * All Rights Reserved.
004 */
005/*
006 * Copyright (C) 2015-2016 UnboundID Corp.
007 *
008 * This program is free software; you can redistribute it and/or modify
009 * it under the terms of the GNU General Public License (GPLv2 only)
010 * or the terms of the GNU Lesser General Public License (LGPLv2.1 only)
011 * as published by the Free Software Foundation.
012 *
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Public License for more details.
017 *
018 * You should have received a copy of the GNU General Public License
019 * along with this program; if not, see <http://www.gnu.org/licenses>.
020 */
021package com.unboundid.util.json;
022
023
024
025import java.io.Serializable;
026
027import com.unboundid.util.NotExtensible;
028import com.unboundid.util.ThreadSafety;
029import com.unboundid.util.ThreadSafetyLevel;
030
031
032
033/**
034 * This class provides the base class for data types that can be used as values
035 * in JSON objects and as elements in JSON arrays.  The types of values defined
036 * in the ECMA-404 specification are:
037 * <UL>
038 *   <LI>
039 *     The {@code null} value, as implemented in the {@link JSONNull} class.
040 *   </LI>
041 *   <LI>
042 *     The Boolean {@code true} and {@code false} values, as implemented in the
043 *     {@link JSONBoolean} class.
044 *   </LI>
045 *   <LI>
046 *     Numeric values, as implemented in the {@link JSONNumber} class.
047 *   </LI>
048 *   <LI>
049 *     String values, as implemented in the {@link JSONString} class.
050 *   </LI>
051 *   <LI>
052 *     Object values (consisting of zero or more name-value pairs), as
053 *     implemented in the {@link JSONObject} class.
054 *   </LI>
055 *   <LI>
056 *     Arrays of JSON values, as implemented in the {@link JSONArray} class.
057 *   </LI>
058 * </UL>
059 */
060@NotExtensible()
061@ThreadSafety(level=ThreadSafetyLevel.INTERFACE_THREADSAFE)
062public abstract class JSONValue
063       implements Serializable
064{
065  /**
066   * A serial version UID for this serializable class.
067   */
068  private static final long serialVersionUID = -4446120225858980451L;
069
070
071
072  /**
073   * Retrieves a hash code for this JSON value.
074   *
075   * @return  The hash code for this JSON value.
076   */
077  public abstract int hashCode();
078
079
080
081  /**
082   * Indicates whether the provided object is equal to this JSON value.
083   *
084   * @param  o  The object to compare against this JSON value.
085   *
086   * @return  {@code true} if the provided object is considered equal to this
087   *          JSON value, or {@code false} if not.
088   */
089  public abstract boolean equals(final Object o);
090
091
092
093  /**
094   * Indicates whether this JSON value is considered equal to the provided JSON
095   * value, subject to the specified constraints.  Note that not all constraints
096   * will apply to all data types.
097   *
098   * @param  v                    The JSON value for which to make the
099   *                              determination.  It must not be {@code null}.
100   * @param  ignoreFieldNameCase  Indicates whether to ignore differences in the
101   *                              capitalization of JSON field names.
102   * @param  ignoreValueCase      Indicates whether to ignore differences in
103   *                              the capitalization of JSON values that
104   *                              represent strings.
105   * @param  ignoreArrayOrder     Indicates whether to ignore differences in the
106   *                              order of elements in JSON arrays.
107   *
108   * @return  {@code true} if this JSON value is considered equal to the
109   *          provided JSON value (subject to the specified constraints), or
110   *          {@code false} if not.
111   */
112  public abstract boolean equals(final JSONValue v,
113                                 final boolean ignoreFieldNameCase,
114                                 final boolean ignoreValueCase,
115                                 final boolean ignoreArrayOrder);
116
117
118
119  /**
120   * Retrieves a string representation of this value as it should appear in a
121   * JSON object, including any necessary quoting, escaping, etc.
122   *
123   * @return A string representation of this value as it should appear in a
124   *          JSON object.
125   */
126  public abstract String toString();
127
128
129
130  /**
131   * Appends a string representation of this value (as it should appear in a
132   * JSON object, including any necessary quoting, escaping, etc.) to the
133   * provided buffer.
134   *
135   * @param  buffer  The buffer to which the information should be appended.
136   */
137  public abstract void toString(final StringBuilder buffer);
138
139
140
141  /**
142   * Retrieves a single-line string representation of this value as it should
143   * appear in a JSON object, including any necessary quoting, escaping, etc.
144   *
145   * @return  A string representation of this value as it should appear in a
146   *          JSON object.
147   */
148  public abstract String toSingleLineString();
149
150
151
152  /**
153   * Appends a single-line string representation of this value (as it should
154   * appear in a JSON object, including any necessary quoting, escaping, etc.)
155   * to the provided buffer.
156   *
157   * @param  buffer  The buffer to which the information should be appended.
158   */
159  public abstract void toSingleLineString(final StringBuilder buffer);
160
161
162
163  /**
164   * Retrieves a normalized string representation of this value.  All equivalent
165   * JSON values must have equivalent normalized representations, even if there
166   * are other legal representations for the value.
167   *
168   * @return  A normalized string representation of this value.
169   */
170  public abstract String toNormalizedString();
171
172
173
174  /**
175   * Appends a normalized string representation of this value to the provided
176   * buffer.  All equivalent JSON values must have equivalent normalized
177   * representations, even if there are other legal representations for the
178   * value.
179   *
180   * @param  buffer  The buffer to which the information should be appended.
181   */
182  public abstract void toNormalizedString(final StringBuilder buffer);
183
184
185
186  /**
187   * Appends this value to the provided JSON buffer.  This will not include a
188   * field name, so it should only be used for Boolean value elements in an
189   * array.
190   *
191   * @param  buffer  The JSON buffer to which this value should be appended.
192   */
193  public abstract void appendToJSONBuffer(final JSONBuffer buffer);
194
195
196
197  /**
198   * Appends a field with the given name and this value to the provided JSON
199   * buffer.
200   *
201   * @param  fieldName  The name to use for the field.
202   * @param  buffer     The JSON buffer to which this value should be appended.
203   */
204  public abstract void appendToJSONBuffer(final String fieldName,
205                                          final JSONBuffer buffer);
206}