How to pass only integer value in key value in nifi - json

Question

I have a use case, where i wants to pass only the integer value in the key datasum, my input data is randomly generates with both the integer and string, whenever the datasum contain the string as below it should replace with 0
input JSON
[
{
"hostname": "ip-192-168-1-1.demo-sample.com",
"detail": "Host name",
"datasum": "ip-192-168-1-1.demo-sample.com",
"toolname": "nifi",
"datacount": "1"
},
{
"hostname": "demo-env",
"detail": "System information",
"datasum": "Windows DEMO-ENV 10.0.19 Microsoft Windows Server 2016",
"toolname": "nifi",
"datacount": "1"
}
]
in above two records datasum having the string value and we need to replace it by 0
expected output
[
{
"hostname": "ip-192-168-1-1.demo-sample.com",
"parametername": "Host name",
"datasum": 0,
"toolname": "nifi",
"datacount": "1",
"severity": "1",
"createdby": "ApacheNifi"
},
{
"hostname": "demo-env",
"parametername": "System information",
"datasum": 0,
"toolname": "nifi",
"datacount": "1",
"severity": "1",
"createdby": "ApacheNifi"
}
]
please suggest.

Answer 1

You can use toInteger function within a modify transformation spec along with a second argument equals to zero such as
[
{
"operation": "modify-overwrite-beta",
"spec": {
"*": {
"datasum": ["=toInteger", 0]
}
}
}
]
In this case, the function would silently stop whenever the value of datasum is string, eg not convertible to integer
the demo on the site http://jolt-demo.appspot.com/ is