本地调试调用sdk返回值 UniJSCallback invoke 一直出错

E/weex: callModuleMethod >>> invoke module:PrinterActivity, method:doReadVehInfo failed. java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at com.taobao.weex.bridge.MethodInvoker.invoke(MethodInvoker.java:46)
at com.taobao.weex.bridge.NativeInvokeHelper.invoke(NativeInvokeHelper.java:87)
at com.taobao.weex.bridge.WXModuleManager.dispatchCallModuleMethod(WXModuleManager.java:249)
at com.taobao.weex.bridge.WXModuleManager.callModuleMethod(WXModuleManager.java:230)
at com.taobao.weex.bridge.WXBridgeManager.callModuleMethod(WXBridgeManager.java:527)
at com.taobao.weex.bridge.WXBridgeManager.callNativeModule(WXBridgeManager.java:709)
at com.taobao.weex.bridge.WXBridge.callNativeModule(WXBridge.java:408)
at com.taobao.weex.base.SystemMessageHandler.nativeRunWork(Native Method)
at com.taobao.weex.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:104)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.os.HandlerThread.run(HandlerThread.java:65)
Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void io.dcloud.feature.uniapp.bridge.UniJSCallback.invokeAndKeepAlive(java.lang.Object)' on a null object reference
at com.sampu.key.PrinterActivity.doReadVehInfo(PrinterActivity.java:71)
at java.lang.reflect.Method.invoke(Native Method) 
at com.taobao.weex.bridge.MethodInvoker.invoke(MethodInvoker.java:46) 
at com.taobao.weex.bridge.NativeInvokeHelper.invoke(NativeInvokeHelper.java:87) 
at com.taobao.weex.bridge.WXModuleManager.dispatchCallModuleMethod(WXModuleManager.java:249) 
at com.taobao.weex.bridge.WXModuleManager.callModuleMethod(WXModuleManager.java:230) 
at com.taobao.weex.bridge.WXBridgeManager.callModuleMethod(WXBridgeManager.java:527) 
at com.taobao.weex.bridge.WXBridgeManager.callNativeModule(WXBridgeManager.java:709) 
at com.taobao.weex.bridge.WXBridge.callNativeModule(WXBridge.java:408) 
at com.taobao.weex.base.SystemMessageHandler.nativeRunWork(Native Method) 
at com.taobao.weex.base.SystemMessageHandler.handleMessage(SystemMessageHandler.java:104) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:193) 
at android.os.HandlerThread.run(HandlerThread.java:65)