NPE while invoking EP with Token EP

[lasanthaS]

Description:

While invoking an endpoint with Token endpoint specified in the HTTP sink, the following exception occurs.

ERROR {io.siddhi.core.stream.StreamJunction} - Error in 'SiddhiApp' after consuming events from Stream 'FooStream', null. Hence, dropping event 'Event{timestamp=1598441762269, data=[***], isExpired=false}' java.lang.NullPointerException
	at io.siddhi.extension.io.http.sink.updatetoken.HttpRequest.sendPostRequest(HttpRequest.java:127)
	at io.siddhi.extension.io.http.sink.updatetoken.HttpsClient.getPasswordGrantAccessToken(HttpsClient.java:95)
	at io.siddhi.extension.io.http.sink.HttpSink.getAccessToken(HttpSink.java:817)
	at io.siddhi.extension.io.http.sink.HttpSink.setAccessToken(HttpSink.java:844)
	at io.siddhi.extension.io.http.sink.HttpSink.sendOauthRequest(HttpSink.java:668)
	at io.siddhi.extension.io.http.sink.HttpSink.publish(HttpSink.java:607)
	at io.siddhi.core.stream.output.sink.Sink.publish(Sink.java:182)
	at io.siddhi.extension.map.json.sinkmapper.JsonSinkMapper.mapAndSend(JsonSinkMapper.java:209)
	at io.siddhi.core.stream.output.sink.SinkMapper.mapAndSend(SinkMapper.java:180)
	at io.siddhi.core.stream.output.sink.SinkCallback.receive(SinkCallback.java:55)
	at io.siddhi.core.stream.StreamJunction.sendEvent(StreamJunction.java:199)
	at io.siddhi.core.stream.StreamJunction$Publisher.send(StreamJunction.java:474)
	at io.siddhi.core.stream.input.InputDistributor.send(InputDistributor.java:34)
	at io.siddhi.core.stream.input.InputEntryValve.send(InputEntryValve.java:45)
	at io.siddhi.core.stream.input.InputHandler.send(InputHandler.java:78)
	at org.wso2.carbon.siddhi.editor.core.internal.DebuggerEventStreamService.pushEvent(DebuggerEventStreamService.java:70)
	at org.wso2.carbon.event.simulator.core.internal.generator.SingleEventGenerator.sendEvent(SingleEventGenerator.java:85)
	at org.wso2.carbon.event.simulator.core.impl.SingleApiServiceImpl.runSingleSimulation(SingleApiServiceImpl.java:17)
	at org.wso2.carbon.event.simulator.core.api.SingleApi.runSingleSimulation(SingleApi.java:63)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.wso2.msf4j.internal.router.HttpMethodInfo.invokeResource(HttpMethodInfo.java:187)
	at org.wso2.msf4j.internal.router.HttpMethodInfo.invoke(HttpMethodInfo.java:143)
	at org.wso2.msf4j.internal.MSF4JHttpConnectorListener.dispatchMethod(MSF4JHttpConnectorListener.java:218)
	at org.wso2.msf4j.internal.MSF4JHttpConnectorListener.lambda$onMessage$0(MSF4JHttpConnectorListener.java:129)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

Affected Product Version:

• WSO2 Streaming Integrator Tooling 1.0.0
• WSO2 Identity server 5.10.0

Steps to reproduce:

The sample Siddhi file is as follows.

@App:name("SiddhiApp")

@sink(type='http', 
    publisher.url='http://jsonplaceholder.typicode.com/posts', 
    method="POST",
    headers="'Content-Type: application/json'",
    oauth.username="***",
    oauth.password="***",
    consumer.key="***",
    consumer.secret="***",
    token.url='https://localhost:9443/oauth2/token',
    ssl.verification.disabled="true",
    @map(
        type='json'
    ))
define stream FooStream (id int);

define stream BarStream(id int);

from BarStream 
select *
insert into FooStream;