I'm new beginner of Elastic Search. One feature I found is that elastic search documents is particularly expressed in JSON. I google a while but I can not found any reason about that.
Can someone help to explain why JSON not XML or other format?
It is because json document has key, value structure and it helps elasticsearch to index on basis of keys. Suppose if there is an XML, then a lot of effort will be required to just parse the data whereas in json , according to key value elastic search can directly index the required data.
Basically there are mainly 2 standard ways to transport data between a server and client, XML and JSON. Old services use XML as well as JSON as a way to transfer data as most of the old consumers of the services are stick to XML parsers, but recent services use JSON as a standard mainly because of simplicity that comes with JSON. JSON parsers are easy to build and use. At the same time XML parsers needs to be customized as per fields. Although there are some great libraries for parsing a XML response like SAX parser in JAVA, its still not that straight forward. Also JSON can be directly used in javascript. I hope I have answered your question.
Related
I'm using protobuf to serialize json from api for flutter app.
however I'm having an issue where I need to serialize this list for example:
"value_array": [ "",
"",
null
]
If I use the usual:
repeated string value_array = 6;
I get an exception during parsing the json.
and sadly I can't have the json changed from api. even worse I can't just manually remove the null from json before parsing it as this element in json is repeated in many different api calls.
PS. I don't need to differentiate the empty string from null, just want to avoid the exception.
thanks in advance for any help.
protobuf has a very opinionated view on JSON, and not all JSON concepts map cleanly to protobuf concepts; for example, protobuf has no notion of null
It might be fine and reasonable to use the protobuf JSON variant if you're always talking protobuf-to-protobuf and want readability (hence text over binary), but if you're working with an external (non-protobuf) JSON tool, honestly: don't use protobuf. Use any relevant JSON-specific tool for your platform - it will do a better job of handling the JSON and supporting your needs. You can always re-map that data to your protobuf model after you have deserialized it, if you need.
I have some neo4j graphs and I want to export their information in a JSON that’s compatible with javascript.D3.
I found a fairly reasonable tutorial of doing so at this link :
https://neo4j.com/developer/example-project/
However, the one thing I don’t understand is how the following data was generated
// JSON object for whole graph viz (nodes, links - arrays)
curl http://localhost:8080/graph[?limit=50]
{"nodes":
[{"title":"Apollo 13","label":"movie"},{"title":"Kevin Bacon","label":"actor"},
{"title":"Tom Hanks","label":"actor"},{"title":"Gary Sinise","label":"actor"},
{"title":"Ed Harris","label":"actor"},{"title":"Bill Paxton","label":"actor"}],
"links":
[{"source":1,"target":0},{"source":2,"target":0},{"source":3,"target":0},
{"source":4,"target":0},{"source":5,"target":0}]}
I don’t understand how the JSON payload above is generated.
All of my neo4j graphs are exported in a neo4j JSON (which is a more complex payload structure than the one above). Which is alright but I specifically want to generate the code shown above. A curl command is just going to fetch existing data, so at the very least I need existing data formatted properly which I don’t have.
I have following requirement
1. Keep responses in an external xml file.
2. Hit the API and compare the response with external response (Kept in xml file. )
3. Also while comparison, I have to ignore dynamic components like , etc.
4. Also I have to ignore sequence of parameters.
Can you please if any such utility/program to do so in JMeter
Thanks in advance
Regards
Vishal Pachpute
I believe it makes more sense to use XML Schema Assertion. This way you will validate your XML response syntax and structure, elements and attributes, number and order of attributes, data types, etc. but this assertion won't care in the slightest about the content.
You can ask the .xsd schema from the developers, most likely they have it, if not the majority of IDEs can do this, there are even online services.
References:
XML Schema Tutorial
How to Use JMeter Assertions in Three Easy Steps
I wanted to write the document to marklogic database using marklogic mapreduce api, lets say here is the example. I wanted to add metadata to the document which i am writing it back to the marklogic database in the reducer -
context.write(outputURI, result);
If adding metadata to the document with mapreduce api of marklogic is possible please let me know.
For Metadata, I am assuming you are talking about the document properties fragment. For background on document properties, please see here: https://docs.marklogic.com/guide/app-dev/properties#id_19516
For use in MarkLogic mapreduce, please see here (the output classes):
https://docs.marklogic.com/guide/mapreduce/output#id_76625
I believe you need to extend/modify your example to also write content to the properties fragment using the PropertyOutputFormat class.
One of the sample applications in the same documentation is an example of saving content in the properties fragment. If, however, you would like to fast-track yourself by looking at some source code: see some examples - including writing to a document property fragment, see here: https://gist.github.com/evanlenz/2484318 - specifically LinkCountInProperty.java
Used property mapreduce.marklogic.output.content.collection with the configuration xml. Adding this property added inserted data to that collection.
Working in front-end we never know the back-end language so how can I know whether the
data coming from back-end is in json or in text or in html or in xml. We don't have an authority or access to back-end language.
Some languages declare this in the first line or 2... Why don't you just read the first few lines or the code?
Many languages will allow you to parse XML, not ideal to wrap it in a catch but it would work. However, you neglected to state what language you are using.
However, it may be worth while agreeing on a format, something like XML which you can then de-serialize ?
You can check Content-Type in Response Headers to know the response data type.