Well I don't know if this is the right way, but it seems to be at least going somewhere. I extracted the files of the jar file and put the all the extracted folder into the class folder of my current program. Then I tried to import the package with
import com.Ostermiller.Syntax.*;
and when I complied it, it works so far.
but when I try to create an object it can not access it:
ToHTML toHTML = new ToHTML();
gets this error message,
--Configuration: TEV3 - j2sdh1.4.2_13 <Default> - <Default>--
C:\Program Files\Xinox Software\JCreatorV4LE\MyProjects\TEV3\src\TEV3.java:22: cannot access com.Ostermiller.Syntax.ToHTML
bad class file: C:\Program Files\Xinox Software\JCreatorV4LE\MyProjects\TEV3\classes\com\Ostermiller\Syntax\ToHTML.class
class file has wrong version 49.0, should be 48.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
ToHTML toHTML = new ToHTML();
First, you don't need to extract the class files from a jar to use them. Just configure your project to use that jar.
The 49.0 / 48.0 indicates the class versions. 48.0 means that you're using JDK 1.4, and 49.0 means that the class that you're using (from that jar) was compiled under JDK 5.0. So, in order to use such a library you'll have to move your own project to JDK 5.0.