Ex 28: Write a program for searching strings for the first occurrence of a character or substring and for the last occurrence of a character or substring.

import java.io.*;
class s08_03
{
public static void main(String[]args) throws Exception
{
int len1,len2,last=0;
DataInputStream in=new DataInputStream(System.in);
System.out.println("Enter the string:");
String s1=in.readLine();
System.out.println("Enter searching string:");
String s2=in.readLine();
len1=s1.length();
len2=s2.length();
for(int i=0;i<=(len1-len2);i++)
{
if(s1.substring(i,len2+i).equals(s2))
{
if(last==0)
System.out.println("first occurance is at possition :"+(i+1));
last=i+1;
}
}
if(last!=0)
System.out.println("last occurance is at possition :"+last);
else
System.out.println("the string is not found");
}
}