UnionCompositeAttributeResolvingStrategy.java 文件源码

@Override
protected Map<String, Object> preprocessValueMap(final Map<?, ?> valueMap) {
    CompositeType openType = getOpenType();

    Preconditions.checkArgument(
            valueMap.size() == 1 && valueMap.containsKey(JavaAttribute.DESCRIPTION_OF_VALUE_ATTRIBUTE_FOR_UNION),
            "Unexpected structure of incoming map, expecting one element under %s, but was %s",
            JavaAttribute.DESCRIPTION_OF_VALUE_ATTRIBUTE_FOR_UNION, valueMap);

    Map<String, Object> newMap = Maps.newHashMap();

    for (String key : openType.keySet()) {
        if (openType.getDescription(key).equals(JavaAttribute.DESCRIPTION_OF_VALUE_ATTRIBUTE_FOR_UNION)) {
            newMap.put(key, valueMap.get(JavaAttribute.DESCRIPTION_OF_VALUE_ATTRIBUTE_FOR_UNION));
        } else {
            newMap.put(key, null);
        }
    }
    return newMap;
}