import java.util.StringTokenizer;

public class StringTokenizerTest {

    public static void main(String[] args)

    {

        String str="数学::英语::语文::化学";

        StringTokenizer st=new StringTokenizer(str,"::");

        System.out.println(st.countTokens());

        while(st.hasMoreTokens())

        {

            System.out.println(st.nextToken());

        }

    }

}