New to Java

Hi ,

I am using hp - ux system with java version "1.4.2.06". when i try to compile a program called CharSequenceDemo.java which is found in the java tutorials at this link

[CharSequenceDemo.java|http://java.sun.com/docs/books/tutorial/java/IandI/examples/CharSequenceDemo.java]


i get the following error:



$/opt/java1.4/bin/javac CharSequenceDemo.java
CharSequenceDemo.java:38: cannot resolve symbol
symbol : class StringBuilder
location: class CharSequenceDemo
StringBuilder sub =
^
CharSequenceDemo.java:39: cannot resolve symbol
symbol : class StringBuilder
location: class CharSequenceDemo
new StringBuilder(s.subSequence(fromEnd(end), fromEnd(start)));
^
CharSequenceDemo.java:44: cannot resolve symbol
symbol : class StringBuilder
location: class CharSequenceDemo
StringBuilder s = new StringBuilder(this.s);
^
CharSequenceDemo.java:44: cannot resolve symbol
symbol : class StringBuilder
location: class CharSequenceDemo
StringBuilder s = new StringBuilder(this.s);
^
4 errors


Please help on how to compile this program.