java - Find substring within a string

I wrote a code to find a substring within a string in java but i want to know is there a short way to do this or is there a inbuilt function to do this.

Here's the code :

import java.util.*;

class substr 
{
    public static void main (String args [])
    {
        String str1 = new String();
        String str2 = new String();
        String str3 = new String();
        int check=1,k;
        Scanner obj= new Scanner (System.in);
        System.out.println("Enter a string");

        str1=obj.nextLine();
        System.out.println("Enter Sub String");
        str2=obj.nextLine();
        int len=str1.length();
        System.out.println(check);
        for( int c = 0 ; c < len&&check!=0 ; c++ )
        {
            for( int i = 1 ; i <= len - c&& check!=0 ; i++ )
            {
                str3 = str1.substring(c, c+i);

                if (str2.equals(str3))
                {   
                    check=0;
                }
            }
       }
       System.out.println(check);
       if (check==0)
       {
           System.out.println("Sub String");

       }
       else if ( check==1)
       {
           System.out.println("No");
       }
    }
}

Answer

If you are asking for a way to do what your code does (check if a string is substring of another string), you can use String#contains:

if(str1.contains(str2)) {
    System.out.println("Sub String");
} else {
    System.out.println("No");
}

---

You can also use String#indexOf:

if(str1.indexOf(str2)>=0) {
    System.out.println("Sub String");
} else {
    System.out.println("No");
}