001/* 002 * Copyright 2015-2017 UnboundID Corp. 003 * All Rights Reserved. 004 */ 005/* 006 * Copyright (C) 2015-2017 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. If the object 122 * containing this value was decoded from a string, then this method will use 123 * the same string representation as in that original object. Otherwise, the 124 * string representation will be constructed. 125 * 126 * @return A string representation of this value as it should appear in a 127 * JSON object. 128 */ 129 public abstract String toString(); 130 131 132 133 /** 134 * Appends a string representation of this value (as it should appear in a 135 * JSON object, including any necessary quoting, escaping, etc.) to the 136 * provided buffer. If the object containing this value was decoded from a 137 * string, then this method will use the same string representation as in that 138 * original object. Otherwise, the string representation will be constructed. 139 * 140 * @param buffer The buffer to which the information should be appended. 141 */ 142 public abstract void toString(final StringBuilder buffer); 143 144 145 146 /** 147 * Retrieves a single-line string representation of this value as it should 148 * appear in a JSON object, including any necessary quoting, escaping, etc. 149 * 150 * @return A string representation of this value as it should appear in a 151 * JSON object. 152 */ 153 public abstract String toSingleLineString(); 154 155 156 157 /** 158 * Appends a single-line string representation of this value (as it should 159 * appear in a JSON object, including any necessary quoting, escaping, etc.) 160 * to the provided buffer. 161 * 162 * @param buffer The buffer to which the information should be appended. 163 */ 164 public abstract void toSingleLineString(final StringBuilder buffer); 165 166 167 168 /** 169 * Retrieves a normalized string representation of this value. All equivalent 170 * JSON values must have equivalent normalized representations, even if there 171 * are other legal representations for the value. 172 * 173 * @return A normalized string representation of this value. 174 */ 175 public abstract String toNormalizedString(); 176 177 178 179 /** 180 * Appends a normalized string representation of this value to the provided 181 * buffer. All equivalent JSON values must have equivalent normalized 182 * representations, even if there are other legal representations for the 183 * value. 184 * 185 * @param buffer The buffer to which the information should be appended. 186 */ 187 public abstract void toNormalizedString(final StringBuilder buffer); 188 189 190 191 /** 192 * Appends this value to the provided JSON buffer. This will not include a 193 * field name, so it should only be used for Boolean value elements in an 194 * array. 195 * 196 * @param buffer The JSON buffer to which this value should be appended. 197 */ 198 public abstract void appendToJSONBuffer(final JSONBuffer buffer); 199 200 201 202 /** 203 * Appends a field with the given name and this value to the provided JSON 204 * buffer. 205 * 206 * @param fieldName The name to use for the field. 207 * @param buffer The JSON buffer to which this value should be appended. 208 */ 209 public abstract void appendToJSONBuffer(final String fieldName, 210 final JSONBuffer buffer); 211}