In java programming write the main and run it for the follow

In java programming write the main and run it for the following method:
public static boolean digitSequence (String s)
    Returns whether s is a valid digitSequence that looks like an int.
It return true if and only if s is a sequence of >0 chars, and every char is a digit in [\'0\',\'9\'] OR
s is a hyphen followed by a sequence of >0 digits. e.g.,
\"0\"    true(simplest case)
\"\" false(empty String doesn\'t qualify)
\"0123456789\" true
long strings are fine:
\"-999999999999999999\" true
\"+1234\" false(the only sign allowed is a single hyphen)
\"-0\" true (another name for 0)
\" 8888888888 \" false(white space not ok)
\"00000000000000012\"   true (leading 0\'s are fine)

Solution

class Check
{
public static boolean isdigitSequence(String str) {
boolean flag = false;

   if (str.length<0)
flag = false;

for (char c : str.toCharArray())
if (\'0\'=< C<=\'9\' || str.charAt(0)==\'-\')
{ flag = true;
}
return flag;
}

public static void main(String args[])
{

boolean check = false;

System.out.println(\"Please enter the string\");
Scanner s = new Scanner(System.in)
str = s.nextLine();

check = isdigitSequence(str);

if(check == true)
{System.out.println(\"The entered string is completley int);
}
else
{System.out.println(\"Entered string does not contain only int);
}

}

}