Common Characters In Two Strings

Common Characters In Two Strings import java.util.*;
class Common
{
public static void main(String args[])
{
Scanner src= new Scanner(System.in);
System.out.println("enter the two strings");
String s1=src.nextLine();
String s2=src.nextLine();
String c="";
StringBuffer sb=new StringBuffer(c);
for(int i=0;i<s2.length();i++)
{
char ch=s2.charAt(i);
    for(int j=0;j<s1.length();j++)
    {
    if(ch==s1.charAt(j))
    {
        int k;
        for( k=0;k<sb.length();k++)

            {
            if(ch==sb.charAt(k))
            break;
            else
            continue;
            }
        if(k>=sb.length())
        sb.append(ch);
    }
    else
    continue;
    }

}
System.out.println(sb);
}
}