Java Code Examples for com.fasterxml.jackson.core.JsonParser#currentName()

@SuppressWarnings("unchecked")
private Map<String, Object> readMap(Class<?> type, JsonParser p, DeserializationContext ctxt) throws IOException {
    if (!p.isExpectedStartObjectToken()) {
        throw new JsonParseException(p, "Expected start of object for Map got " + p.currentToken());
    }
    try {
        Map<String, Object> value = (Map<String, Object>) type.getDeclaredConstructor().newInstance();
        JsonToken next = p.nextToken();
        while (next != JsonToken.END_OBJECT) {
            if (next != JsonToken.FIELD_NAME) {
                throw new JsonParseException(p, "Key was not present " + next);
            }
            String key = p.currentName();
            p.nextToken(); // position to next
            Object val = readObject(p, ctxt);
            value.put(key, val);
            next = p.nextToken();
        }
        return value;
    } catch (InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {
        throw new JsonMappingException(p, "Can not create empty map for class " + type + " @ " + p.getCurrentLocation(),
                                       e);
    }
}
 

@SuppressWarnings("unchecked")
@Override
public T deserialize(JsonParser p, DeserializationContext ctxt)
        throws IOException
{
    // Ok: must point to START_OBJECT or FIELD_NAME
    JsonToken t = p.currentToken();
    if (t == JsonToken.START_OBJECT) { // If START_OBJECT, move to next; may also be END_OBJECT
        t = p.nextToken();
    }
    if (t != JsonToken.FIELD_NAME && t != JsonToken.END_OBJECT) {
        // !!! 16-Sep-2019, tatu: Should use full generic type, for error message,
        //   but would require more refactoring (to extend `StdDeserializer` f.ex)
        return (T) ctxt.handleUnexpectedToken(ctxt.constructType(handledType()), p);
    }

    I map = createIntermediate();
    for (; p.currentToken() == JsonToken.FIELD_NAME; p.nextToken()) {
        // Must point to field name now
        String fieldName = p.currentName();
        p.nextToken();
        deserializeEntry(map, ctxt, fieldName, p);
    }
    return finish(map);
}
 

/**
 * Consume json object with the given consumer by iterating over its entries
 *
 * @param jsonParser: jsonParser to consume. currentToken() must return START_OBJECT at the beginning.
 * @param consumer:   consumer taking two arguments: json key and the current jsonParser.
 *                    The consumer must only parse and finishes to parse the corresponding value.
 * @throws IOException
 */
static void consumeJson(
        @Nonnull final JsonParser jsonParser,
        final PartialJsonConsumer consumer
) throws IOException {
    // The current position of jsonParser must be "{".
    Preconditions.checkState(jsonParser.currentToken() == JsonToken.START_OBJECT);

    while (jsonParser.nextToken() != JsonToken.END_OBJECT) {
        // The token right after "{" must be field name.
        Preconditions.checkState(jsonParser.currentToken() == JsonToken.FIELD_NAME);

        // Get the current field name.
        final String key = jsonParser.currentName();

        // Go to the next token, which is the beginning of the corresponding value.
        jsonParser.nextToken();

        // consumer must consume the corresponding value.
        consumer.accept(key, jsonParser);
    }
}
 

protected static String _tokenDesc(JsonParser p, JsonToken t) throws IOException {
    if (t == null) {
        return "NULL";
    }
    switch (t) {
    case FIELD_NAME:
        return "JSON Field name '"+p.currentName()+"'";
    case START_ARRAY:
        return "JSON Array";
    case START_OBJECT:
        return "JSON Object";
    case VALUE_FALSE:
        return "'false'";
    case VALUE_NULL:
        return "'null'";
    case VALUE_NUMBER_FLOAT:
    case VALUE_NUMBER_INT:
        return "JSON Number";
    case VALUE_STRING:
        return "JSON String";
    case VALUE_TRUE:
        return "'true'";
    default:
        return t.toString();
    }
}
 

@SuppressWarnings("unchecked")
@Override
public IEnum<?> deserialize(JsonParser parser,
		DeserializationContext context)
		throws IOException, JsonProcessingException {
	// 目标对象
	Object currentValue = parser.getCurrentValue();
	// 目标对象的字段
	String currentName = parser.currentName();
	// 枚举类型以及值类型
	Class<IEnum<?>> enumType = (Class<IEnum<?>>) BeanUtils
			.findPropertyType(
					currentName, currentValue.getClass());
	Class<?> valueType = TYPE_CACHE.get(enumType);
	if (valueType == null) {
		valueType = ReflectUtil.getActualClass(enumType, IEnum.class,
				"V");
		TYPE_CACHE.put(enumType, valueType);
	}
	// 获取值并转换
	Object value = parser.readValueAs(valueType);
	if (value != null) {
		for (IEnum<?> e : enumType.getEnumConstants()) {
			if (e.getValue().equals(value)) {
				return e;
			}
		}
	}
	return null;
}
 

@SuppressWarnings("unchecked")
@Override
public IEnum<?> deserialize(JsonParser parser,
		DeserializationContext context)
		throws IOException, JsonProcessingException {
	// 目标对象
	Object currentValue = parser.getCurrentValue();
	// 目标对象的字段
	String currentName = parser.currentName();
	// 枚举类型以及值类型
	Class<IEnum<?>> enumType = (Class<IEnum<?>>) BeanUtils
			.findPropertyType(
					currentName, currentValue.getClass());
	Class<?> valueType = TYPE_CACHE.get(enumType);
	if (valueType == null) {
		valueType = ReflectUtil.getActualClass(enumType, IEnum.class,
				"V");
		TYPE_CACHE.put(enumType, valueType);
	}
	// 获取值并转换
	Object value = parser.readValueAs(valueType);
	if (value != null) {
		for (IEnum<?> e : enumType.getEnumConstants()) {
			if (e.getValue().equals(value)) {
				return e;
			}
		}
	}
	return null;
}
 

@Override
public Object deserialize(JsonParser parser, DeserializationContext context) throws IOException {
    // check if the current claim key is mapped, if so traverse it's value
    String name = parser.currentName();
    if (claimTypeMap != null && name != null && claimTypeMap.containsKey(name)) {
        Class type = claimTypeMap.get(name);
        return parser.readValueAsTree().traverse(parser.getCodec()).readValueAs(type);
    }
    // otherwise default to super
    return super.deserialize(parser, context);
}
 

@Override
protected T _deserializeEntries(JsonParser p, DeserializationContext ctxt)
    throws IOException, JsonProcessingException
{
    final KeyDeserializer keyDes = _keyDeserializer;
    final JsonDeserializer<?> valueDes = _valueDeserializer;
    final TypeDeserializer typeDeser = _valueTypeDeserializer;

    ImmutableMap.Builder<Object, Object> builder = createBuilder();
    for (; p.currentToken() == JsonToken.FIELD_NAME; p.nextToken()) {
        // Must point to field name now
        String fieldName = p.currentName();
        Object key = (keyDes == null) ? fieldName : keyDes.deserializeKey(fieldName, ctxt);
        // And then the value...
        JsonToken t = p.nextToken();
        // 28-Nov-2010, tatu: Should probably support "ignorable properties" in future...
        Object value;            
        if (t == JsonToken.VALUE_NULL) {
            if (!_skipNullValues) {
                value = _nullProvider.getNullValue(ctxt);
                // 14-Sep-2015, tatu: As per [datatype-guava#52], avoid exception due to null
                // TODO: allow reporting problem via a feature, in future?
                if (value != null) {
                    builder.put(key, value);
                }
            }
            continue;
        }
        if (typeDeser == null) {
            value = valueDes.deserialize(p, ctxt);
        } else {
            value = valueDes.deserializeWithType(p, ctxt, typeDeser);
        }
        builder.put(key, value);
    }
    // No class outside of the package will be able to subclass us,
    // and we provide the proper builder for the subclasses we implement.
    @SuppressWarnings("unchecked")
    T map = (T) builder.build();
    return map;
}