Example usage for com.google.gwt.json.client JSONValue isNull

Introduction

In this page you can find the example usage for com.google.gwt.json.client JSONValue isNull.

Prototype

public JSONNull isNull()

Source Link

Document

Returns a non-null reference if this JSONValue is really a JSONNull.

Usage

From source file:rpc.client.data.JSONSerializer.java

License:Open Source License

private Object fromJSONValue(JSONValue jsonValue, Type expected) throws NoSuitableSerializableFactory {

    if (jsonValue == null) {
        return null;
    }/*from  w ww .j  av a 2 s  . c o  m*/

    // Null
    JSONNull asNull = jsonValue.isNull();
    if (asNull != null) {
        return null;
    }

    // Boolean
    JSONBoolean asBoolean = jsonValue.isBoolean();
    if (asBoolean != null) {
        return asBoolean.booleanValue();
    }

    // Integer
    // Long
    // Float
    // Double
    JSONNumber asNumber = jsonValue.isNumber();
    if (asNumber != null) {
        double value = asNumber.doubleValue();

        if (expected.isInteger()) {
            return (int) value;
        }

        if (expected.isLong()) {
            return (long) value;
        }

        if (expected.isFloat()) {
            return (float) value;
        }

        if (expected.isDouble()) {
            return value;
        }
    }

    // String
    // Enum
    JSONString asString = jsonValue.isString();
    if (asString != null) {
        if (expected.isEnum()) {
            String value = asString.stringValue();
            return Enum.valueOf((Class) expected.getTypeClass(), value);
        } else {
            return asString.stringValue();
        }
    }

    // Map
    // Serializable
    JSONObject asObject = jsonValue.isObject();
    if (asObject != null) {
        if (expected.isMap()) {
            Map<Object, Object> map = new HashMap<Object, Object>();

            Type keyType = expected.getParameterized(0);
            Type valueType = expected.getParameterized(1);

            if (!(keyType.isString() || keyType.isEnum())) {
                return null;
            }

            for (String key : asObject.keySet()) {
                JSONValue value = asObject.get(key);

                if (keyType.isString()) {
                    map.put(key, fromJSONValue(value, valueType));
                }

                if (keyType.isEnum()) {
                    map.put(Enum.valueOf((Class) keyType.getTypeClass(), key), fromJSONValue(value, valueType));
                }
            }

            return map;
        } else {
            if (provider == null) {
                throw new NoSuitableSerializableFactory();
            }

            Serializable object = provider.make(expected);

            for (Map.Entry<String, Type> entry : object.fields().entrySet()) {

                String field = entry.getKey();
                Type fieldType = entry.getValue();

                JSONValue value = asObject.get(field);
                object.set(field, fromJSONValue(value, fieldType));
            }

            return object;
        }
    }

    // List
    JSONArray asArray = jsonValue.isArray();
    if (asArray != null) {
        int size = asArray.size();

        List<Object> list = new ArrayList<Object>();
        Type itemType = expected.getParameterized(0);

        for (int i = 0; i < size; i++) {
            JSONValue value = asArray.get(i);
            list.add(fromJSONValue(value, itemType));
        }

        return list;
    }

    return null;
}