启动SIP会话/getClientTransaction(请求)时出现问题引发NullPointerException

我有一个小问题,我让我的SIP客户端工作,我改变了代码的结构。我保持了SIP对象的创建过程与以前一样,但现在不起作用了。

位于gov.nist.javax.sip.siproviderImpl.getNewClientTransaction(siproviderImpl。java:285)

以下是sip的实例化代码:

        sipFactory.setPathName(host);
        sipFactory.resetFactory();
        sipStack = sipFactory.createSipStack(getProperties());
        String address = Inet4Address.getLocalHost().getHostAddress();
        sipFactory.createHeaderFactory();
        sipFactory.createAddressFactory();
        sipFactory.createMessageFactory();

        udpPoint = sipStack.createListeningPoint(address, SIPPort, SIPConstants.UDP);
        udpSipProvider = sipStack.createSipProvider(udpPoint);
        udpSipProvider.addSipListener(this);

        tcpPoint = sipStack.createListeningPoint(address, SIPPort, SIPConstants.TCP);
        tcpSipProvider = sipStack.createSipProvider(tcpPoint);
        tcpSipProvider.addSipListener(this);

        sipStack.start();
        setSessionState(SipSessionState.Connected);

有什么帮助吗??

亚当。