ClassCastException at runtime test

Let us see the ClassCastException at runtime test in generics with the below example.

ClassCastException at run time test example:

GenericsTest.java

import java.util.ArrayList; import java.util.List;   /** * This class is used to show the * ClassCastException at runtime test. * @author javawithease */ public class GenericsTest { public static void main(String args[]){ //Arraylist without generics. List list1 = new ArrayList(); list1.add("Roxy"); list1.add("Sandy"); list1.add(new Integer(6)); try{ //Retrieve and print list elements. for(Object obj : list1){ //ClassCastException at runtime when //try to cast an integer to string. String str=(String) obj; System.out.println(str); } }catch(ClassCastException e){ System.out.println(); System.out.println(); e.printStackTrace(); }     //Arraylist with generics. List list2 = new ArrayList(); list2.add("Roxy"); list2.add("Sandy"); list2.add("Sunil");   //Retrieve and print list elements. for(String str : list2){ //No ClassCastException at runtime //because casting is not required. System.out.println(str); }   } }

Output:

Roxy Sandy java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String Roxy Sandy Sunil at com.javawithease.business.GenericsTest.main (GenericsTest.java:23)