# U.java

## How to use

when creating a new Gson object (you must use a GsonBuilder), do
```java
GsonBuilder builder = new GsonBuilder();
//...
builder.registerTypeAdapterFactory(new U.Factory());
```

Then, you can use
```java
class Demo {
	U<String, Integer> id;
}
```
...

```java
Demo demo = gson.fromJson("{\"id\":1}", Demo.class);
Integer intid = demo.id.getVal(Integer.class);
```
or
```java
Demo demo = gson.fromJson("{\"id\":\"1\"}", Demo.class);
String strid = demo.id.getVal(String.class);
```