GenericTypeIndicator

abstract classGenericTypeIndicator<T>

Due to the way that Java implements generics (type-erasure), it is necessary to use a slightly more complicated method to properly resolve types for generic collections at runtime. To solve this problem, Firebase Database accepts subclasses of this class in calls to getValue (getValue,getValue) and returns a properly-typed generic collection.

As an example, you might do something like this to get a list of Message instances from aDataSnapshot:

classMessage{privateStringauthor;privateStringtext;privateMessage(){}publicMessage(Stringauthor,Stringtext){this.author=author;this.text=text;}publicStringgetAuthor(){returnauthor;}publicStringgetText(){returntext;}}// Later ...GenericTypeIndicator<List<Message>>t=newGenericTypeIndicator<List<Message>>(){};List<Message>messages=snapshot.getValue(t);

Summary

GenericTypeIndicator()