java - Setting a parameter for returned string values -

i trying create game user enters phrase, phrase can in lower case letters (if catch drift). program prompt user do-while loop. if user enters (1234567890, or !@#$%^&* or asdfgh, loop should re-prompt user enter lower case letters. extremely new java, code going shitty. here is:

import java.util.scanner; public class program05  {     public static void main(string[] args)      {     scanner scanner01 = new scanner(system.in);     string inputphrase;      char inputchar;         {             system.out.print("enter common phrase begin!: ");             inputphrase = scanner01.nextline();           } while (!inputphrase.equals(character.digit(0,9)));     } } 

use string.matches() appropriate regex test if it's lowercase letters:

inputphrase.matches("[a-z ]+") // consists of characters a-z , spaces 

so loop like:

do {     system.out.print("enter common phrase begin!: ");     inputphrase = scanner01.nextline();  } while (!inputphrase.matches("[a-z ]+"));