This example will show how to initialize an ArrayList using various techniques found in java and guava.
Straight up Java
This is a standard way to initialize an array list in JDK 5.0 and above.
Java 7 introduced the diamond operator which reduces java's verbosity on having to specify a generic type. The compiler will infer the parameter type based on the constructor's generic class. The snippet below will show how to initilize a ArrayList using the diamond operator.
Double brace initialization
Using double brace initialization is probably more controversial as it creates an anonymous inner classes and should be used judiciously.