Nifi evaluatejsonpath json array


Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. I've been lately reading lot of useful answers posted here, that helped me with previous doubts I had. I've decided to join the community and post my first question.

Already investigated previously if there are answers, but couldn't find a workaround to my issue. I'm new to Apache NiFi. I need to set a very simple flow which is getting some specific tweets from Twitter, extract the message from it and write to to a local folder.

Looks like the EvaluateJsonPath is not doing the job of extracting the tweet's message from the json. In its properties tab, I've set the following:. The whole flow is working, tweets are captured and go through the EvaluateJsonPath and then to PutFile, which is writing all coming tweets in almost real time, to a specific folder in my PC.

However, the files I see written in my folder, are json with all the attributes of a tweet. Does anyone have a clue on what am I doing wrong? Maybe is there a better solution to make it happen? Remember my target: I want to pick only the messages from all tweets and store them in my PC. Additional question: is it possible to store those messages as. Thanks very much in advance for everyone reading my question and posting an answer if there is one :.

Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Asked 2 years, 6 months ago. Active 1 year, 11 months ago. Viewed times. Good afternoon SuperUser folks. In its properties tab, I've set the following: Destination: flowfile-attribute; Return-type: auto-detect Path Not Found Behavior: ignore Null Value Representation: empty string I then added a property as below: twitter.

Thanks very much in advance for everyone reading my question and posting an answer if there is one : Kind regards, Luis Pastor.

Improve this question. Luis Pastor Luis Pastor 11 1 1 bronze badge. Add a comment. Active Oldest Votes.Find centralized, trusted content and collaborate around the technologies you use most.

Connect and share knowledge within a single location that is structured and easy to search. I have got json file with nested structure. I use splitjson first and then evaluatejsonpath processor to select element I am interested in. Works fine with single element to be returned but when I add more properties and change to flow file attribute. It returns the array from splitjson processor.

Any help much appreciated. If, after that, your EvaluateJsonPath points at a field that is an array, the array will be returned. If you want a flow file for each element in that array, you'll need another SplitJson processor. If your EvaluateJsonPath is putting the result s in an attribute, the flow file content will remain the same i. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?

Collectives on Stack Overflow. Learn more. Evaluatejsonpath returning complete array Ask Question. Asked 4 years, 7 months ago. Active 4 years, 7 months ago. Viewed 4k times. Improve this question. Jimmy Jimmy 17 1 1 silver badge 4 4 bronze badges.

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Set. ConcurrentHashMap. ConcurrentLinkedQueue. ConcurrentMap. StringUtils. DynamicProperty .Keith Lim Fri, 13 May Skip to site navigation Press enter. Re: How to extract scalar info of json array using EvaluateJsonPath processor? Thanks Aldrin for providing a clear sample in such a short time. That Advanced menu implementation is very eye-opening.

Hi Keith, I threw together a quick example of how this is done and made it available as a GitHub Gist [1].

1-2 Extract values from JSON data

In that template, the core logic of transforming the evaluated JsonPath expression result is in the "Count IDs as Attribute" processor which is making use of the 'Advanced' menu for UpdateAttribute. As a caveat, this is quite quick and dirty, but illustrates how you can extract values from content to attributes for your case.

This approach is taken in the referenced template. I additionally noticed that I was also incorrect in my previous statement and overlooked the length operator for the JsonPath library [2]. This, however, does not seem to apply to expressions for EvaluateJsonPath and will likely need some additional inspection. I have created an issue for that [3].

Please let us know if you have any additional questions! What is the builtin variable that points to the flowfile content that I can used with the expression language? For illustration, let's say I have the below json as the content of a flowfile. What processor can I used to take this flowfile as input and how can I extract the count of item in the json array "results" below.

I want to assign it to a user defined attribute in the processor. Hi Keith, Scanning over some of the docs, it does not appear that JsonPath supports a count operator but could possibly be used to extract from your source document that could possibly be manipulated using something like allDelinatedValues [1].

Certainly not the most elegant approach, but could work. If you would like some additional help, a sample to work from would be nice to give some more concrete assistance. Does the Nifi Expression Language in combination of json path feature supports this without writing script? What is the syntax?View solution in original post.

Thanks in advance. Hello, sorry for the delay. JSONPath itself has filtering capabilities. Many examples can be found on this page. I have some sort of the same scenario. But this doesn't work. Please suggest for the above scenario. So i put the json into EvaluateJsonPath processor and converted into flowfile attributes. Support Questions. Find answers, ask questions, and share your expertise.

Turn on suggestions. Auto-suggest helps you quickly drexel hill down your search results by suggesting possible matches as you type. Showing results for. Search instead for. Did you mean:. Cloudera Community : Support : Support Questions : Nifi processor - route json array into multiple js Solved Go to solution. Reply 14, Views. Tags 5. All forum topics Previous Next. Accepted Solutions. Reply 8, Views. Reply 6, Views.Starting with NiFi 1.

Before that, you had few options requiring a bit of additional work to get things working see here. Have a look at the ForkRecord documentation additional details for examples. The corresponding Avro schema can be found here. You can get some help using the InferAvroSchema processor but this should only be used to get an initial version of your Avro schema when you start developing your workflows it should not be used as a processor used in your production workflows.

The GenerateFlowFile is very simple:. Here the flow file content before the processor:. If you need to manipulate your records to go from windows 10 wpf vs uwp schema to another, you can use the UpdateRecord processor. The goal here is to extract the data contained in the arrays into separated CSV files. Here is the configuration of my CSV writer:.

To use it, I need to specify a custom property containing the Record path to the array that the processor should process, then you have two modes for the processor:. Note — if you have multiple Record paths pointing to multiple arrays with elements using the same output schema, you can define as many custom properties as you want. The ForkRecord processor is a new processor that you can use if you need to manipulate schema oriented data containing a lot of arrays.

That can be useful in case you need to normalize data before ingestion into databases. Note — look at the new features in NiFi 1. It raises the question of the performances and I will briefly expose my observations in this post.

However, depending of your use case, you might need specific features. The main issue is to force the generation of an array when you only have one single element in your input. It provides a way to force the creation of an array. To do that, you need to insert a tag into your XML input file. The tag to insert is. But for this tag to be correctly interpreted, you also need to specify the corresponding namespace:.

In the end, using ReplaceText processors with regular expressions, you need to have the following input for the example 2 :. Conclusion: you need to use regular expressions to add a namespace in the first tag of your document and add the JSON array tag in every tag wrapping elements that should be part of an array.

Here is an example of custom processor doing the conversion. And here is a Groovy version for the ExecuteScript processor. What about arrays with this solution? Also, you might have to do some other transformations like removing the namespaces or replacing empty strings. To force arrays, the easiest approach is to double every tag that should be converted into an array. With the example 2, I transform my input to have:.

And, then, I can use another ReplaceText processor to remove the unwanted empty strings created by the conversion. What about the performances now?Evaluates one or more JsonPath expressions against the content of a FlowFile. The results of those expressions are assigned to FlowFile Attributes or are written to the content of the FlowFile itself, depending on configuration of the Processor.

JsonPaths are entered by adding user-defined properties; the name of the property maps to the Attribute Name into which the result will be placed if the Destination is flowfile-attribute; otherwise, the property name is ignored.

Setting an attribute with a dynamic property name

The value of the property must be a valid JsonPath expression. A Return Type of 'auto-detect' will make a determination based off the configured destination. When 'Destination' is set to 'flowfile-attribute,' a return type of 'scalar' will be used. If Destination is 'flowfile-content' and the JsonPath does not evaluate to a defined path, the FlowFile will be routed to 'unmatched' without having its contents modified.

If Destination is flowfile-attribute and the expression matches nothing, attributes will be created with empty strings as the value, and the FlowFile will always be routed to 'matched.

In the list below, the names of required properties appear in bold. Any other properties not in bold are considered optional. The table also indicates any default values. Dynamic Properties allow the user to specify both the name and value of a property. Supports Expression Language: false. Indicates whether the results of the JsonPath evaluation are written to the FlowFile content or a FlowFile attribute; if using attribute, must specify the Attribute Name property.

If set to flowfile-content, only one JsonPath may be livecd de linux descargar, and the property name is ignored. Selecting 'auto-detect' will set the return type to 'json' for a Destination of 'flowfile-content', and 'scalar' for a Destination of 'flowfile-attribute'.

Indicates how to handle missing JSON path expressions when destination is set to 'flowfile-attribute'. Selecting 'warn' will generate a warning when a JSON path expression is not found.

FlowFiles are routed to this relationship when the JsonPath does not match the content of the FlowFile and the Destination is set to flowfile-content.

FlowFiles are routed to this relationship when the JsonPath is successfully evaluated and the FlowFile is modified as a result. The point is passing the same JSON flow-file into two EvaluateJsonPath processors, then each EvaluateJsonPath extract array based on its own interest. enerbiom.eu › questions › evaluatejsonpath-returning-complete-array.

Your JSONPath in SplitJson needs to point to an array to be split. If, after that, your EvaluateJsonPath points at a field that is an array. enerbiom.eu › enerbiom.euteJsonPath. If the JsonPath evaluates to a JSON array or JSON object and the Return Type is set to 'scalar' the FlowFile will be unmodified and will be routed to failure.

A. A) Fetch json array from json object using EvaluateJsonPath in Apache Nifi. For a given json find phoneNumbers json array. {. "firstName": "John". Expressions are assigned to Attributes or written to content of the FlowFile.

Tags: JSON, evaluate, JsonPath. Properties: In the list below, the names of. This example introduces the EvaluateJsonPath processor and demonstrates how to extract an ID value from JSON data to use in constructing the URI. May 12, PM To: [email protected] Subject: Re: How to extract scalar info of json array using EvaluateJsonPath processor? Example: evaluatejsonpath array json { "firstName": "John", "lastName": "Smith", "isAlive": verdadeiro, "idade": 25, "endereço": { "streetAddress": "21 2nd.

I have the following JSON: { "hits": { "hits":[] } }. (Some response from ElasticSearch). I want to use the processor EvaluateJsonPath to get the length of. + "If the JsonPath evaluates to a JSON array or JSON object and the Return Type is set to 'scalar' the FlowFile will be unmodified and will be routed to failure. Я использую EvaluateJsonPath, чтобы извлечь одно конкретное значение из JSON. Я использую следующее выражение JSONPath: $.data[?(@. Then we continue the loop until we reach the last element in the array, or the element is null or not a JSON Object.

Customizing Capabilities in. evaluatejsonpath array jsonhow to get whole json object with jsonpathhow to get all json object with jsonpathwhat is jsonpath?extracting data using json. evaluatejsonpath array jsonhow to get whole json object with jsonpathhow to get all json object with jsonpathwhat is jsonpath?json array get json. I am using EvaluateJsonPath to extract one particular value from JSON. I am using the follwoing JSONPath But somehow nifi is returning empty array.

If the JsonPath evaluates to a JSON array or JSON object and the Return Type is set to Fields inherited from class enerbiom.eurd. The class is part of the package ➦ Group: enerbiom.eu ➦ Artifact: + "If the JsonPath evaluates to a JSON array or JSON object and the Return Type.

I recently had to work on a NiFi workflow to process millions of XML documents per day. One of the step being the conversion of the XML data into JSON. It.