Thread: Need good books on generics

hi,

I am iStore developer,mostly working on jsp pages.
I do have knowledge on core java.But new to generics.
Can anyone provide book references on generics.Or any links relatated to generics can be helpful for me.

Thanks,
Sabitha

I read a tutorial about generics,but it was in greek.So i can only post you the examples of it,not the link(if you wish the link too ask for it )

 
package generics;
 
 
public class Main{
 
 
    public static void main(String[] args) {
        Integer[] int_array = {1,2,3,5,5}; //in Generic basic types such as int,double,char
        //can not be used,so we use instead Inetger,Double,Character.The point is that at Gene
        //rics we can play only with Classes ,not with basic types(e.g. int).Notice that 
        //Integer,etc. are classes
        Character[] char_array = {'s','a','b','h'};
 
        int s1=12;
        char s2='a';
 
        /*Purpose of function contains is to see if a symbol is part of a sequence(e.g. an 
         * array)
         */
        if(contains(int_array,s1))
        {
            System.out.println("Found" + s1);
        }
        else
            System.out.println(  s1 + " Not found...\n");
 
        if(contains(char_array,s2))
        {
            System.out.println("Found " + s2);
        }
        else
            System.out.println(  s2 + " Not found...\n");
 
    }
 
    //The generic type is placed before the return type of the function
    public static <E> boolean contains(E[] a,E x)
    {
        for(E element : a)//traverse all the elements of array a
        {
            if(x.equals(element))//equals is a function that is for use to us by JAVA
            {
                return true;
            }
        }
        return false;
    }
}

and about safety of Generics

 
package genericsafety;
 
import java.util.*;
 
public class Main{
 
 
    public static void main(String[] args) {
        List<Integer> l =new ArrayList();
 
        //insert some random numbers at that list
        l.add(5);
        l.add(100);
 
        //Error because the list is for int and we insert String
        //l.add("this will cause error");
    }
}