Import org.json.JSONObject; JSONObject obj = new JSONObject(jsonString); String command = obj.getString(“command”);
From: Daniela S [mailto:[email protected]] Sent: dinsdag 24 mei 2016 18:08 To: [email protected] Subject: Aw: Re: Re: Split Kafka JSON String Hi, unfortunately it does not work. Do I need this step? Or is it also possible to extract the value of a specific field out of my JSON string? So my JSON string is for example {"timestamp": "23462626", "ID1": "1", "ID2": "100", "command": "START"} I would like to use a filter bolt to filter for START and END. So I have to access the command field within the JSON string. Afterwards I would like to store the START JSONs in Redis. The key should be ID1 and ID2. Is that possible? What would be the best way to store it in Redis and to define two keys for each value? The END JSONs should be deleted from Redis. Thank you in advance. Regards, Daniela Gesendet: Montag, 16. Mai 2016 um 14:08 Uhr Von: "Henry Hottelet" <[email protected]<mailto:[email protected]>> An: [email protected]<mailto:[email protected]> Betreff: Re: Re: Split Kafka JSON String https://code.google.com/archive/p/json-simple/ import org.json.simple.JSONObject; void main() { String yourString; String key; JSONObject j = yourString; Redis.put(key,j); } — Henry Hottelet 646-543-6104 (Google Voice: cell/sms) [email protected] (Email) http://www.linkedin.com/in/hottelet (LinkedIn) https://technologyventureslimited.appointlet.com (Schedule appointment) This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by Henry Hottelet as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. On May 16, 2016, at 4:11 AM, Daniela S <[email protected]> wrote: Henry, thank you for your help. I did not use any github link for my project. I tried to build the project on my own, with the help of some books and available code parts from the Internet. I try to explain what I am doing: 1. I have generated random JSON data with a JSON data generator from the Internet the JSON data looks as follows: {"timestamp": "nowTimestamp()", "ID1": "integer(1,1000)", "ID2": "integer(1,100)", "command": "random('START','END')" } The JSON generator simulates a data stream, sending the data to a specific Kafka topic as String 2. I would like to have a KafkaSpout to fetch the data from the Kafka topic. 3. Then I would like to store all the events containing "START" into Redis and to delete all the events containing "END" from Redis. The key should be a combination of ID1 and ID2. 4. In the next step I would like to pull all the entries stored in Redis and to add a specific value for every entry (this values is located in a database and I have to look it up for every entry). Then I would like to use these values to build a sum over all entries. This should be repeated every minute, as there might have been new start or end events. I thought I could use a sliding window for that. But unfortunately I have no idea how to proceed with the JSON String, I receive from Kafka. I already read a lot about the possibility to store JSON Strings in Redis, but I have no idea how to build the key with both IDs and how to access the fields in the JSON String. Hope you can help me. Thank you so much in advance! Regards, Daniela Gesendet: Sonntag, 15. Mai 2016 um 22:07 Uhr Von: "Henry Hottelet" <[email protected]> An: [email protected] Betreff: Re: Aw: Re: Split Kafka JSON String Daniella, I am curious about your architecture with Kafka and storm. Can you send the github link you used for that project? I would like to be able to see your example. I use IntelliJ. Henry Sent from my iPad On May 15, 2016, at 2:14 PM, Daniela S <[email protected]<mailto:[email protected]>> wrote: Hi, thank you very much for your answers. But unfortunately I do not have a JSON object yet, I only have a String, containing a JSON object. I receive the Strings from Kafka but I do not know how to get the information out of the String. example: {"timestamp": 1463335828342, "ID":570,"command":"START"} I would like to extract the three fields out of the String. Then I would like to store it into Redis. Afterwards I would like to pull all the stored (active) devices out of Redis and to build a sum over all the devices every minute. For building the sum I have to add another value for every device. I would like to use Redis as a kind of cache. Regards, Daniela Gesendet: Sonntag, 15. Mai 2016 um 20:06 Uhr Von: "Henry Hottelet" <[email protected]<mailto:[email protected]>> An: [email protected]<mailto:[email protected]> Betreff: Re: Split Kafka JSON String Try using intellij plug in that converts json to pojo classes On May 15, 2016 2:04 PM, "Nathan Leung" <[email protected]<mailto:[email protected]>> wrote: Easiest way is to map your job to a pojo and use Jackson or gson to convert the json. On May 15, 2016 1:48 PM, "Daniela S" <[email protected]<mailto:[email protected]>> wrote: Hi I am receiving Strings of JSON from Kafka. I would like to split the string to get each field from the JSON object to store it into Redis. How can I split the string and assign the parts to variables? Thank you in advance. Regards, Daniela
