groovy filter fields in json response

Question

I'm trying to filter out some fields in my JSON response. Sample response below:

{
  "Status": "Fail",
  "Code": "500",
  "Rules": [{
      "Status": "Fail",
      "Message": "Code error",
      "id": "123456"
    },
    {
      "Status": "Fail",
      "Message": "Configuration error",
      "id": "12345"
    }
  ]
}

I want to omit code and id fields and print rest of the fields in JSON. the final response should look like this:-

{
  "Status": "Fail",
  "Rules": [{
      "Status": "Fail",
      "Message": "Code error"
    },
    {
      "Status": "Fail",
      "Message": "Configuration error"
    }
  ]
}

Any idea on how we can achieve it?

Answer 1

Groovy already provide classes and mechanisms to do this, first you need to import class groovy.json.JsonGenerator

Then you can define the fields that you want to ignore from serilization:

def generator = new JsonGenerator.Options()
    .excludeFieldsByName('id', 'Code')
    .build()

And finally just need to parse the output:

String output = generator.toJson(input)

The output will look something like this:

{
    "Status": "Fail",
    "Rules": [
        {
            "Status": "Fail",
            "Message": "Code error"
        },
        {
            "Status": "Fail",
            "Message": "Configuration error"
        }
    ]
}

Here is a full sample of how I did this:

import groovy.json.JsonSlurper
import groovy.json.JsonOutput
import groovy.json.JsonGenerator

String json = '''{
  "Status": "Fail",
  "Code": "500",
  "Rules": [{
      "Status": "Fail",
      "Message": "Code error",
      "id": "123456"
    },
    {
      "Status": "Fail",
      "Message": "Configuration error",
      "id": "12345"
    }
  ]
}'''

Map input = new JsonSlurper().parseText(json)

def generator = new JsonGenerator.Options()
    .excludeFieldsByName('id', 'Code')
    .build()

String output = generator.toJson(input)

println JsonOutput.prettyPrint(output)

To see more configurations for this JsonGenerator class you can go to official documentation here: https://groovy-lang.org/json.html#_customizing_output

Answer 2

 var getData = { "Status": "Fail", "Code": "500", "Rules": [{ "Status": "Fail", "Message": "Code error", "id": "123456" }, { "Status": "Fail", "Message": "Configuration error", "id": "12345" } ] }; delete getData.Code; for (var i = 0; i < getData.Rules.length; i++) { delete getData.Rules[i].id; } console.log(getData);

Note:- You can simply use delete elementValue to achieve that

Answer 3

 const obj = { "Status": "Fail", "Code": "500", "Rules": [ { "Status": "Fail", "Message": "Code error", "id": "123456" }, { "Status": "Fail", "Message": "Configuration error", "id": "12345" } ] } const result = Object.keys(obj).reduce((acc, curr) => { if (curr.== "Code") { acc = {..,acc: [curr]. obj[curr] } } if (curr === "Rules") { acc = {..,acc: [curr]. obj[curr].map(rule => { delete rule,id return rule }) } } return acc }. {}) console.log(result)

Answer 4

A solution which recursively walks through your json and removes specific fields on any depth:

import groovy.json.*

def str = '''
{
  "Status": "Fail",
  "Code": "500",
  "Rules": [{
      "Status": "Fail",
      "Message": "Code error",
      "id": "123456"
    },
    {
      "Status": "Fail",
      "Message": "Configuration error",
      "id": "12345"
    }
  ]
}'''

def json  = new JsonSlurper().parseText(str)
def clean = recursivelyRemove(json, ['id', 'Code'])

println JsonOutput.prettyPrint(JsonOutput.toJson(clean))

def recursivelyRemove(obj, fieldNames) {
  switch(obj) {
    case Map:
      obj.findAll { k, v -> 
        !(k in fieldNames)
      }.collectEntries { k, v -> 
        [k, recursivelyRemove(v, fieldNames)]
      }
      break
    case List:
      obj.collect { recursivelyRemove(it, fieldNames) }
      break
    default: 
      obj
  }
}

which prints:

─➤ groovy solution.groovy                                                                                              1 ↵
{
    "Status": "Fail",
    "Rules": [
        {
            "Status": "Fail",
            "Message": "Code error"
        },
        {
            "Status": "Fail",
            "Message": "Configuration error"
        }
    ]
}

when run.

This has the upside that it is not hard-coded to your json structure, ie if the structure changes for some reason, this code might still work.

A potential downside is that if your json structure is very deep (say hundreds or thousands of levels of nesting), you might get a StackOverflowException as we are making recursive calls. This might or might not be likely depending on your scenario.