Java I/O - 如何按值类型扫描String

import java.util.Scanner;

public class MainClass {
  public static void main(String args[]) {
    String instr = "10 99.88 scanning is easy.";
    Scanner conin = new Scanner(instr);

    while (conin.hasNext()) {
      if (conin.hasNextDouble()) {
        System.out.println(conin.nextDouble()); 
      }
    }

  }
}