Making a call using Java Telephony API

Hi, I currently working on a project in which i need to make a call using JTAPI and record that call. I m new to JTAPI, I tried running the code specified in

Java Telephony API (JTAPI) Specification<br> Version 1.4 <br>(Final Release): Package javax.telephony
but its throwing following exception :

Exception in thread "main" java.lang.ClassFormatError: Name index 0 in LocalVariableTable has bad
constant type in class file com/lucent/jtapi/tsapi/TsapiPeer at line :

JtapiPeer peer = JtapiPeerFactory.getJtapiPeer(null);

in OutCall class. I have included all required JAR's. Can anyone please help me with this?:(sweat):