So a couple notes based on your debug statements.
"2.1 -> 2.2" If you do not plan to provide an input to this processor and
run it on cron or timer, you can just do the session.create at the top.
This will create a new flowfile. If you do expect an incoming flow file
just return in the null check and the next trigger will try the get() again
until it receives a flowfile.
"3 -> 3.1" You are not providing the actual string, you are passing a
static value of "JSON_PATH". I would do a "final String jsonPath =
context.getProperty(JSON_PATH);" around comment 2.3 and then use jsonPath
in your FileReader.
Object obj = new JSONParser().parse(new FileReader("JSON_PATH"));
Hope this helps,
Phillip
On Tue, Jul 23, 2019 at 10:13 PM Farooq Mustafa <farooq.must...@gmail.com>
wrote:
> Hello,
>
>
> I am writing my first custom processor. I followed the example here
> https://www.nifi.rocks/developing-a-custom-apache-nifi-processor-json/
>
>
> In the settings, I have /tmp/jsoniput/sample1.json file
>
>
> The source code;
>
> public void onTrigger(final ProcessContext context, final ProcessSession
> session) throws ProcessException {
>
> final AtomicReference<String> value = new AtomicReference<>();
> getLogger().warn("sample - Farooq - 1 , value = <" + value.toString() +
> ">");
>
> FlowFile flowfile = session.get();
> getLogger().warn("sample - Farooq - 2");
>
> if ( null == flowfile) {
> getLogger().warn("sample - Farooq - 2.1 - flowfile is NULL *** ");
> flowfile = session.create();
> flowfile = session.get();
> getLogger().warn("sample - Farooq - 2.2 - session.create() /
> session.get() --- NOT SURE ");
> }
> getLogger().warn("sample - Farooq - 2.3 JSON_PATH :" +
> context.getProperty(JSON_PATH).getValue());
>
> session.read(flowfile, new InputStreamCallback() {
> @Override
> public void process(InputStream in) throws IOException {
>
> try {
> getLogger().warn("sample - Farooq - 3 JSON_PATH :" +
> context.getProperty(JSON_PATH).getValue());
> Object obj = new JSONParser().parse(new FileReader("JSON_PATH"));
> getLogger().warn("sample - Farooq - 3.1 ");
>
>
>
> The log output:
>
> 2019-07-20 13:58:42,625 WARN [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] sample - Farooq - 1
> , value = <null>
>
> 2019-07-20 13:58:42,625 WARN [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] sample - Farooq - 2
>
> 2019-07-20 13:58:42,625 WARN [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] sample - Farooq -
> 2.1 - flowfile is NULL ***
>
> 2019-07-20 13:58:42,625 WARN [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] sample - Farooq -
> 2.2 - session.create() / session.get() --- NOT SURE
>
> 2019-07-20 13:58:42,625 WARN [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] sample - Farooq -
> 2.3 JSON_PATH :/tmp/jsoninput
>
> 2019-07-20 13:58:42,626 ERROR [Timer-Driven Process Thread-4]
> o.a.nifi.processors.sitc.JsonProcessor
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267]
> JsonProcessor[id=fd8fe4ca-016b-1000-a6ed-c0e224bc7267] failed to process
> session due to java.lang.NullPointerException; Processor Administratively
> Yielded for 1 sec: java.lang.NullPointerException
>
> java.lang.NullPointerException: null
>
> at
> org.apache.nifi.controller.repository.StandardProcessSession.getRecord(StandardProcessSession.java:574)
>
> at
> org.apache.nifi.controller.repository.StandardProcessSession.validateRecordState(StandardProcessSession.java:3132)
>
> at
> org.apache.nifi.controller.repository.StandardProcessSession.read(StandardProcessSession.java:2187)
>
>
> And the basic flow:
> [image: image.png]
>
>
>
> Any ideas or guidance will be appreciated.
>
>
> Thanks
>
> Farooq
>
