Program to count the frequency of a given word in a string.

/* Program to count the frequency of a given word in a string. */

import java.io.DataInputStream;     // to load DataInputStream class        

class P23
{
    public static void main(String args[ ])
    {
        String str = new String();
        String search = new String();
        int i,len1,len2,index=-1,count=0;
        DataInputStream in = new DataInputStream(System.in);

        try
        {
            System.out.print("Enter String : ");
            str = in.readLine();
            System.out.print("Enter a word to be searched in string : ");
            search = in.readLine();
        }
        catch(Exception e) {  System.out.println("I/O Error");   }

        len1 = str.length();
        len2 = search.length();
        for(i=0;i<=len1-1;i=index+len2)
        {
            index=str.indexOf(search,i);
            if(index!=-1)
                count++;
            else
                break;
        }       
        System.out.println(" Total No. of Occurrences of word '"+search+"' in given string is :"+count);
    }
}