public static Object gsonToPrimitive(JsonElement element) {
if (element.isJsonPrimitive()) {
JsonPrimitive prim = element.getAsJsonPrimitive();
if (prim.isString()) {
return prim.getAsString();
} else if (prim.isBoolean()) {
return prim.getAsBoolean();
} else if (prim.isNumber()) {
return prim.getAsNumber();
} else {
throw new IllegalArgumentException("Unknown Gson primitive: " + prim);
}
} else if (element.isJsonArray()) {
JsonArray array = element.getAsJsonArray();
List<Object> list = new ArrayList<Object>();
for (int i = 0; i < array.size(); i++) {
list.add(gsonToPrimitive(array.get(i)));
}
return list;
} else if (element.isJsonNull()) {
return null;
} else if (element.isJsonObject()) {
Map<String, Object> map = new HashMap<String, Object>();
for (Map.Entry<String, JsonElement> entry : element.getAsJsonObject().entrySet()) {
map.put(entry.getKey(), gsonToPrimitive(entry.getValue()));
}
return map;
} else {
throw new IllegalArgumentException("Unknown Gson value: " + element);
}
}
@Override
public JsonType visitDeclared(DeclaredType declaredType, Void o) {
if (isJsonPrimitive(declaredType)) {
// 'primitive'-ish things
return new JsonPrimitive(declaredType.toString());
} else if (isInstanceOf(declaredType, Collection.class)) {
if (declaredType.getTypeArguments().size() == 0) {
return new JsonArray(new JsonPrimitive(Object.class.getName()));
} else {
TypeMirror elem = declaredType.getTypeArguments().get(0);
return new JsonArray(elem.accept(this, o));
}
} else if (isInstanceOf(declaredType, Map.class)) {
if (declaredType.getTypeArguments().size() == 0) {
return new JsonDict(
new JsonPrimitive(Object.class.getName()), new JsonPrimitive(Object.class.getName()));
} else {
TypeMirror key = declaredType.getTypeArguments().get(0);
TypeMirror val = declaredType.getTypeArguments().get(1);
return new JsonDict(key.accept(this, o), val.accept(this, o));
}
} else {
TypeElement element = (TypeElement) declaredType.asElement();
if (element.getKind() == ElementKind.ENUM) {
List<String> enumConstants = new ArrayList();
for (Element e : element.getEnclosedElements()) {
if (e.getKind() == ElementKind.ENUM_CONSTANT) {
enumConstants.add(e.toString());
}
}
JsonPrimitive primitive =
new JsonPrimitive(String.class.getName()); // TODO is this always a string?
primitive.setRestrictions(enumConstants);
return primitive;
} else {
return buildType(declaredType, element);
}
}
}
private Object getObjectFromPrimitive(JsonPrimitive json) {
if (json.isBoolean()) {
return json.getAsBoolean();
} else if (json.isString()) {
return json.getAsString();
} else if (json.isNumber()) {
return json.getAsNumber();
}
return null;
}
private boolean isJsonPrimitive(TypeMirror typeMirror) {
return (typeMirror.getKind().isPrimitive() || JsonPrimitive.isPrimitive(typeMirror.toString()));
}