Please help me figure out the problem. I program in groovy (you can use a java example, it looks like there). Json comes to the input, in which it is not known how many fields. There can be 5 fields, maybe 10, maybe 50. My task is to process this json and return the data back using:
// Names of dataset columns
def names = ["a", "b", "c"];
// types of return values in each column (for any field (column) json is always String)
def types = ["String", "String", "String"];
// formation of the dataset header
reader.outputLinesSetHeaders (names, types);
// Passing the data itself from json
reader.outputLines ([it.a, it.b, it.c])
// Close the dataset
reader.outputLinesEnd ();
If I knew the incoming json, then I would have set the required field names, the number of "String" in advance and returned their values by referring to a specific json field. The example below shows 3 json fields: auto, home, job. Accordingly, 3 times "String" for each of the fields and referring to a specific field to return the value of it.auto, it.home, it.job. But how can I do the same if I don't know the incoming json?
import groovy.json.JsonSlurper
import ru.itrpro.xm.plugins.groovy.ResultSetReader;
class XM_PARSE_XLS {
def execute(ResultSetReader reader, String pfile) {
def jsonSlurper = new JsonSlurper()
def list = jsonSlurper.parseText(pfile)
//The names of the columns of the dataset (now set statically to show an example; but in my case I don't know json and can't write it this way in advance)
def names = ["AUTO", "HOME", "JOB"];
//return types in each column (for any json, only "String" types)
def types = ["String", "String", "String"];
//формирование заголовка датасета
reader.outputLinesSetHeaders(names,types);
list.each {
//pass the values as a dataset from json (now set statically to show an example; but in my case I don't know json and can't write it this way in advance)
reader.outputLines([it?.AUTO, it?.HOME, it?.JOB]);
}
//closing dataset
reader.outputLinesEnd();
return null;
}
static void main(String... args) {
String pfile = """
[{"AUTO":"bmw",
"HOME":"vest",
"JOB":"bbds"},
{"AUTO":"audi",
"HOME":"dest",
"JOB":"aads"},
{"AUTO":"opel",
"HOME":"lest",
"JOB":"ffds"}]
"""
def SSC = new XM_PARSE_XLS()
def res = SSC.execute(new ResultSetReader(), pfile)
}
}
Perhaps it is worth collecting all the field names of the incoming json into a list and specifying a list of "String" (any incoming json has all fields only "String") with the same number as the fields? But how to do this and how then should I pass the field values (it. ***)?
If the input JSON is of type Object (key-value pairs), it's parsed to a Map
, so you can use it's methods to inspect it.
import groovy.json.JsonSlurper
String pfile = """
[{"AUTO":"bmw",
"HOME":"vest",
"JOB":1},
{"AUTO":"audi",
"HOME":"dest",
"JOB":2},
{"AUTO":"opel",
"HOME":"lest",
"JOB":3}]
"""
def jsonSlurper = new JsonSlurper()
def list = jsonSlurper.parseText pfile
List names = list.inject( new HashSet() ){ res, map ->
res.addAll map.keySet()
res
}.toList()
// get types based on actual values
def types = list.first().values()*.getClass()*.simpleName
assert '[AUTO, JOB, HOME]' == names.toString()
assert '[String, String, Integer]' == types.toString()
//reader.outputLinesSetHeaders names, types
list.each{ e ->
//reader.outputLines names.collect{ e[ it ] }
println names.collect{ e[ it ] }
}
//reader.outputLinesEnd()
The lines are commented out to avoid compilation problems.