This topic is about Java Generics – Parameterized Types.
A Generic class can have parameterized types where a type parameter can be substituted with a parameterized type. Following example will showcase above mentioned concept.
Example
Create the following java program using any editor of your choice.
GenericsTester.java
package com.Adglob;
import java.util.ArrayList;
import java.util.List;
public class GenericsTester {
public static void main(String[] args) {
Box<Integer, List<String>> box
= new Box<Integer, List<String>>();
List<String> messages = new ArrayList<String>();
messages.add("Hi");
messages.add("Hello");
messages.add("Bye");
box.add(Integer.valueOf(10),messages);
System.out.printf("Integer Value :%d\n", box.getFirst());
System.out.printf("String Value :%s\n", box.getSecond());
}
}
class Box<T, S> {
private T t;
private S s;
public void add(T t, S s) {
this.t = t;
this.s = s;
}
public T getFirst() {
return t;
}
public S getSecond() {
return s;
}
}
This will produce the following result.
Output
Integer Value :10 String Value :[Hi, Hello, Bye]
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