java.awt.Robot

 import java.awt.AWTException;
 import java.awt.Robot;
 import java.awt.event.KeyEvent;

 public class TestRobot {
     Robot man;

     public static void main(String[] args) throws AWTException {
         new TestRobot();
     }

     public TestRobot() throws AWTException {
         man = new Robot();
         man.mouseMove(300, 300);
         String s = "weidwiao is great";
         int k = KeyEvent.VK_A;
         for (char i : s.toCharArray()) {
             if (Character.isAlphabetic(i))
                 i = Character.toUpperCase(i);
             else if(Character.isSpaceChar(i))
                 i=KeyEvent.VK_SPACE;
             man.keyPress(i);
             man.keyRelease(i);
             man.delay(1000);
         }
     }
 }