How to compare two strings ?

Source:

public class CompareStrings { 
  public static void main(String[] args) { 
    String string1 = "This is a string."; 
    String string2 = "This is a string."; 
    String string3 = "This is a different string."; 
 
    // if 0 then strings are the same
    System.out.print("string1.compareTo(string2) :");
    System.out.println(string1.compareTo(string2));

    System.out.print("string1.compareTo(string3) :");
    System.out.println(string1.compareTo(string3));

    // if true then strings are the same
    System.out.print("string1.equals(string2) :");
    System.out.println(string1.equals(string2));

    System.out.print("string1.equals(string3) :");
    System.out.println(string1.equals(string3));
  } 
}

Output:

   $ java CompareStrings 
   string1.compareTo(string2) :0
   string1.compareTo(string3) :15
   string1.equals(string2) :true
   string1.equals(string3) :false