java写的 echo 和 linux系统自带的 echo 效率差别很大！

[nbz@localhost 0]$ uname -o
GNU/Linux
[nbz@localhost 0]$ which echo
/bin/echo
[nbz@localhost 0]$ time /bin/echo 1234
1234

real	0m0.011s
user	0m0.001s
sys	0m0.009s
[nbz@localhost 0]$ ls
echo.java
[nbz@localhost 0]$ cat echo.java 
public class echo {
  public static void main(String []args) {
    if (args != null) {
      System.out.printf("%s\n", args[0]);
    }
  }
}
[nbz@localhost 0]$ javac echo.java 
[nbz@localhost 0]$ which java
/usr/bin/java
[nbz@localhost 0]$ time /usr/bin/java echo 1234
1234

real	0m0.208s
user	0m0.026s
sys	0m0.181s
[nbz@localhost 0]$