Generics in Java

The Java Generics programming is introduced in J2SE 5 to deal with type-safe objects.
Before generics, we can store any
type of objects in collection i.e. non-generic. Now generics, forces the java programmer to store specific type of objects.

Advantage of Java Generics

There are mainly 3 advantages of generics. They are as follows:

1) Type-safety : We can hold only a single type of objects in generics. It doesn’t allow to store other objects.

2) Type casting is not required: There is no need to typecast the object.

Before Generics, we need to type cast.

List list = new ArrayList(); 
list.add("hello"); 
String s = (String) list.get(0);//typecasting 
After Generics, we don't need to typecast the object.

List<String> list = new ArrayList<String>(); 
list.add("hello"); 
String s = list.get(0); 

3) Compile-Time Checking: It is checked at compile time so problem will not occur at runtime. The good programming strategy says it is far better to handle the problem at compile time than runtime.

List<String> list = new ArrayList<String>(); 
list.add("hello"); 
list.add(32);//Compile Time Error
Syntax to use generic collection

ClassOrInterface<Type>
Example to use Generics in java

ArrayList<String>