Java 11 and 12 – New Features

Type inference in Java 7

Java 7 introduced type inference for constructor arguments with generics. Consider the following line of code:

List<String> myThings = new ArrayList<String>(); 

In Java 7, the preceding line of code could be replaced with the following:

List<String> myThings = new ArrayList<>();  

The preceding code shouldn't be confused with the following, which is trying to mix the generics with the raw types:

List<String> myThings = new ArrayList();  

Java 7 also allowed type inference to invoke generic methods. For a generic method (say, print()) defined in a class (say, MyClass), the code would be as follows:

class MyClass<T> { 
   public <X> void print(X x) { 
         System.out.println(x.getClass()); 
   } 
}  

The preceding code can be called ...