1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 | package Torello.Java.JSON; import javax.json.*; import java.lang.reflect.*; import java.math.*; import java.util.function.Function; import static javax.json.JsonValue.ValueType.*; import static Torello.Java.JSON.JFlag.*; import static Torello.Java.JSON.RJInternal.*; /** * Builds on the J2EE Standard Release JSON Parsing Tools by providing additional * help with converting JSON Data into Java Object-Data. * * <EMBED CLASS='external-html' DATA-FILE-ID=GLASS_FISH_NOTE> * <EMBED CLASS='external-html' DATA-FILE-ID=READ_JSON> * <EMBED CLASS='external-html' DATA-FILE-ID=JOS> * * @see Json * @see JsonObject * @see JsonArray */ @Torello.JavaDoc.StaticFunctional @Torello.JavaDoc.JDHeaderBackgroundImg(EmbedTagFileID="JSON_JDHBI") public class ReadJSON { // This is a static class. Has no program state. private ReadJSON() { } // ******************************************************************************************** // ******************************************************************************************** // Object // ******************************************************************************************** // ******************************************************************************************** /** * Retrieve a {@link JsonArray} element, and transform it to a Java {@code Object} (POJO). * <EMBED CLASS='external-HTML' DATA-FILE-ID=JR_PC_NOTE> * <EMBED CLASS=defs DATA-JTYPE=JsonObject DATA-TYPE='Type Parameter T'> * * @param <T> <EMBED CLASS='external-html' DATA-FILE-ID=JR_TYPE_T> * @param ja Any instance of {@link JsonArray} * @param index <EMBED CLASS='external-html' DATA-FILE-ID=JR_INDEX_JA> * @param c <EMBED CLASS='external-html' DATA-FILE-ID=JR_CLASS> * @param throwOnNull <EMBED CLASS='external-html' DATA-FILE-ID=JR_TON_JA> * @return <EMBED CLASS='external-html' DATA-FILE-ID=JR_RET_TON_JA> * * @throws IndexOutOfBoundsException If {@code 'index'} is out of bounds of {@code 'ja'} * @throws JsonTypeArrException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JTAEX> * @throws JsonNullArrException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JNAEX> * @throws JsonException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JEX_REFL> */ public static <T> T getObject(JsonArray ja, int index, Class<T> c, boolean throwOnNull) { // This will throw an IndexOutOfBoundsException if the index is out of bounds. JsonValue jv = ja.get(index); switch (jv.getValueType()) { case NULL: // This is simple-stuff (not rocket-science). "Type Mapping" Code has to worry // about what the meaning of "null" should be. if (throwOnNull) throw new JsonNullArrException(ja, index, OBJECT, c); else return getObject(null, c); case OBJECT: return getObject((JsonObject) jv, c); // The JsonValue at the specified array-index does not contain a JsonObject. default: throw new JsonTypeArrException(ja, index, OBJECT, jv, c); } } /** * Extract a {@link JsonObject} property, and transform it to a Java {@code Object} (POJO). * <EMBED CLASS='external-HTML' DATA-FILE-ID=JR_PC_NOTE> * <EMBED CLASS=defs DATA-TYPE='Type Parameter T' DATA-JTYPE=JsonObject> * * @param <T> <EMBED CLASS='external-html' DATA-FILE-ID=JR_TYPE_T> * @param jo Any instance of {@link JsonObject}. * @param propertyName <EMBED CLASS='external-html' DATA-FILE-ID=JR_PN_JO> * @param isOptional <EMBED CLASS='external-html' DATA-FILE-ID=JR_ISOPT_JO> * @param throwOnNull <EMBED CLASS='external-html' DATA-FILE-ID=JR_TON_JO> * @return <EMBED CLASS='external-html' DATA-FILE-ID=JR_RET_TON_JO> * * @throws JsonPropMissingException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JPMEX> * @throws JsonTypeObjException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JTOEX> * @throws JsonNullObjException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JNOEX> * @throws JsonException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JEX_REFL> */ public static <T> T getObject( JsonObject jo, String propertyName, Class<T> c, boolean isOptional, boolean throwOnNull ) { if (! jo.containsKey(propertyName)) { if (isOptional) return null; throw new JsonPropMissingException(jo, propertyName, OBJECT, c); } JsonValue jv = jo.get(propertyName); switch (jv.getValueType()) { case NULL: // This is simple-stuff (not rocket-science). "Type Mapping" Code has to // worry about what the meaning of "null" should be. if (throwOnNull) throw new JsonNullObjException(jo, propertyName, OBJECT, c); return getObject(null, c); case OBJECT: return getObject((JsonObject) jv, c); // The JsonObject propertydoes not contain a JsonObject. default: throw new JsonTypeObjException(jo, propertyName, OBJECT, jv, c); } } /** * This class contains a lot of the reason / impetus for writing {@code 'ReadJSON'}. This * does converts a {@link JsonObject} into a Java-Object. The actual binding must be * implemented by the programmer - because the class-type that is passed to this method * (parameter {@code 'c'}) must have a constructor accepting this {@code JsonObject}. * * <EMBED CLASS='external-html' DATA-FILE-ID=JR_PC_NOTE> * @param <T> <EMBED CLASS='external-html' DATA-FILE-ID=JR_TYPE_T> * * @param jo This may be any {@link JsonObject} which can be bound to {@code 'c'}. * <BR /><BR /><B>NOTE:</B> This parameter may be null, and if it is, null is passed to the * {@code 'c'} constructor. * * @param c <EMBED CLASS='external-html' DATA-FILE-ID=JR_CLASS> * @return An instance of the class {@code 'T'}, which is specified by {@code 'c'} * @throws JsonException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JEX_REFL> */ public static <T> T getObject(JsonObject jo, Class<T> c) { Constructor<T> ctor = null; try { // This just gets a "Constructor" using Reflection. The main point is that the // Constructor must have exactly one parameter - and that parameter must have a // type "JsonObject" (basic java.lang.reflect stuff) // //System.out.println("c.getName:():" + c.getName()); ctor = c.getDeclaredConstructor(JsonObject.class); } catch (Exception e) { if (c.getEnclosingClass() != null) { int modifiers = c.getModifiers(); if ((! Modifier.isStatic(modifiers)) || (! Modifier.isPublic(modifiers))) throw new JsonException( "Unable to retrieve POJO Constructor for class: " + "[" + c.getName() + "]\n" + "Your class appears to be a Nested-Class, however it has not been " + "declared public and static. There is no way to retrieve a " + "1-Argument JsonObject Constructor for Nested-Type's unless the " + "type has been declared BOTH static AND public.\n" + "See Exception.getCause() for details.", e ); } else throw new JsonException( "Unable to retrieve POJO Constructor for class: [" + c.getName() + "]\n" + "Do you have a one-argument, public, constructor for this class?\n" + "Does it accept a JsonObject in its parameter list?\n" + "See Exception.getCause() for details.", e ); } // If the user has requested a class that doesn't have that kind of constructor, then // there is no way to build the object. Throw an exception. if (ctor == null) throw new JsonException( "The class which was passed to parameter 'c' [" + c.getName() + "] does not " + "appear to have a constructor with precisely one parameter of type JsonObject." ); // Call that constructor using the parameter 'jo', and return that instance / object try { return ctor.newInstance(jo); } // NOTE: There are *MANY* possible Exception's that may be thrown by reflective // operations like those above. Furthermore, they are *ALL* checked exceptions. // The code below wraps those exceptions into an UN-CHECKED / RuntimeException // (JsonException) catch (Exception e) { throw new JsonException( "Unable to instantiate class: [" + c.getName() + "] using provided " + "Java-Object\n" + "See Exception.getCause() for details.", e ); } } // ******************************************************************************************** // ******************************************************************************************** // String // ******************************************************************************************** // ******************************************************************************************** /** * Retrieve a {@link JsonArray} element, and transform it to a {@code java.lang.String}. * <EMBED CLASS=defs DATA-JTYPE=JsonString DATA-TYPE='java.lang.String'> * * @param ja Any instance of {@link JsonArray} * @param index <EMBED CLASS='external-html' DATA-FILE-ID=JR_INDEX_JA> * @param throwOnNull <EMBED CLASS='external-html' DATA-FILE-ID=JR_TON_JA> * @return <EMBED CLASS='external-html' DATA-FILE-ID=JR_RET_TON_JA> * * @throws IndexOutOfBoundsException If {@code 'index'} is out of the bounds of {@code 'ja'} * @throws JsonTypeArrException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JTAEX> * @throws JsonNullArrException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JNAEX> * * @see JsonValue#getValueType() * @see JsonValue.ValueType#STRING */ public static String getString(JsonArray ja, int index, boolean throwOnNull) { // This will throw an IndexOutOfBoundsException if the index is out of bounds. JsonValue jv = ja.get(index); switch (jv.getValueType()) { case NULL: // This is simple-stuff (not rocket-science). "Type Mapping" Code has to worry // about what the meaning of "null" should be. if (throwOnNull) throw new JsonNullArrException(ja, index, STRING, String.class); else return null; case STRING: return ((JsonString) jv).getString(); // The JsonValue at the specified array-index does not contain a JsonString. default: throw new JsonTypeArrException(ja, index, STRING, jv, String.class); } } /** * Extract a {@link JsonObject} property, and transform it to a {@code java.lang.String}. * <EMBED CLASS=defs DATA-TYPE='java.lang.String' DATA-JTYPE=JsonString> * * @param jo Any instance of {@link JsonObject}. * @param propertyName <EMBED CLASS='external-html' DATA-FILE-ID=JR_PN_JO> * @param isOptional <EMBED CLASS='external-html' DATA-FILE-ID=JR_ISOPT_JO> * @param throwOnNull <EMBED CLASS='external-html' DATA-FILE-ID=JR_TON_JO> * @return <EMBED CLASS='external-html' DATA-FILE-ID=JR_RET_TON_JO> * * @throws JsonPropMissingException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JPMEX> * @throws JsonTypeObjException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JTOEX> * @throws JsonNullObjException <EMBED CLASS='external-html' DATA-FILE-ID=JR_JNOEX> * * @see JsonValue#getValueType() * @see JsonValue.ValueType#STRING */ public static String getString (JsonObject jo, String propertyName, boolean isOptional, boolean throwOnNull) { if (! jo.containsKey(propertyName)) { if (isOptional) return null; throw new JsonPropMissingException(jo, propertyName, STRING, String.class); } JsonValue jv = jo.get(propertyName); switch (jv.getValueType()) { case NULL: // This is simple-stuff (not rocket-science). "Type Mapping" Code has to worry // about what the meaning of "null" should be. if (throwOnNull) throw new JsonNullObjException (jo, propertyName, STRING, String.class); else return null; case STRING: return ((JsonString) jv).getString(); // The JsonObject propertydoes not contain a JsonString. default: throw new JsonTypeObjException(jo, propertyName, STRING, jv, String.class); } } } |