OnJava8-Examples/generics/GenericArray2.java
2015-09-07 11:44:36 -06:00

38 lines
954 B
Java

// generics/GenericArray2.java
// ©2015 MindView LLC: see Copyright.txt
public class GenericArray2<T> {
private Object[] array;
public GenericArray2(int sz) {
array = new Object[sz];
}
public void put(int index, T item) {
array[index] = item;
}
@SuppressWarnings("unchecked")
public T get(int index) { return (T)array[index]; }
@SuppressWarnings("unchecked")
public T[] rep() {
return (T[])array; // Warning: unchecked cast
}
public static void main(String[] args) {
GenericArray2<Integer> gai =
new GenericArray2<>(10);
for(int i = 0; i < 10; i ++)
gai.put(i, i);
for(int i = 0; i < 10; i ++)
System.out.print(gai.get(i) + " ");
System.out.println();
try {
Integer[] ia = gai.rep();
} catch(Exception e) {
System.out.println(e);
}
}
}
/* Output:
0 1 2 3 4 5 6 7 8 9
java.lang.ClassCastException: [Ljava.lang.Object; cannot be
cast to [Ljava.lang.Integer;
*/