android - SipDemo示例代码提供了NullPointerException

我正在开发SIP应用程序。我使用了SipDemo中的sipdemo样本，但有问题。我得到了nullpointerexception=>“尝试关闭管理器时出错。”在这里（异常“e”）：

public void initiateCall() {

    updateStatus(sipAddress);

    try {
        SipAudioCall.Listener listener = new SipAudioCall.Listener() {

            @Override
            public void onCallEstablished(SipAudioCall call) {
                call.startAudio();
                call.setSpeakerMode(true);
                call.toggleMute();
                updateStatus(call);
            }

            @Override
            public void onCallEnded(SipAudioCall call) {
                updateStatus("Ready.");
            }
        };

        call = manager.makeAudioCall(me.getUriString(), sipAddress, listener, 30);

    }
    catch (Exception e) {
        Log.i("WalkieTalkieActivity/InitiateCall", "Error when trying to close manager.", e);
        if (me != null) {
            try {
                manager.close(me.getUriString());
            } catch (Exception ee) {
                Log.i("WalkieTalkieActivity/InitiateCall",
                        "Error when trying to close manager.", ee);
                ee.printStackTrace();
            }
        }
        if (call != null) {
            call.close();
        }
    }
}

另外，我检查了这个SipManager.isApiSupported()和SipManager.isVoipSupported()都返回了false。我在tab上用4.0.3操作系统测试这个。我想知道问题是否出在不支持本机SIP上，但我可以很容易地用SIPDroid或其他来自Market的应用程序打电话。
编辑
日志堆栈跟踪：

05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247): Error when trying to close manager.
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247): java.lang.NullPointerException
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at com.example.android.sip.WalkieTalkieActivity.initiateCall(WalkieTalkieActivity.java:212)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at com.example.android.sip.WalkieTalkieActivity$4.onClick(WalkieTalkieActivity.java:324)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:165)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at android.os.Looper.loop(Looper.java:130)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at android.app.ActivityThread.main(ActivityThread.java:3691)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at java.lang.reflect.Method.invokeNative(Native Method)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at java.lang.reflect.Method.invoke(Method.java:507)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:907)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:665)
05-15 22:29:11.255: INFO/WalkieTalkieActivity/InitiateCall(4247):     at dalvik.system.NativeStart.main(Native Method)

最佳答案

我想我有办法了。并非每个版本的android都支持sip。因此，您应该查找第三部分库。例如，您可以查看Sipdroid或CSipSimple的源代码并根据自己的需要进行转换。