How to parse single quote special charater using Gson library in Scala - json

I am unable to parse json file if values contain single quote and other characters as '()= etc
Hi I have the following Json file:
{
"config": {
"inputDFName": "testInput",
"conditions": "site_type = 'micro'"
}
}
The parser class like
case class FilterConfig(inputDFName: String,conditions: String)
I am parsing json using below function
def readDataFilter(conf:String): FilterConfig ={
val gson = new Gson()
gson.fromJson(conf,classOf[FilterConfig])
}
But return error like : com.google.gson.JsonSyntaxException:com.google.gson.stream.MalformedJsonException
but if i remove single quotes and equal to sign its working fine.
Please help here.

I see two problems here.
inputDFName in JSON is not matching with testDFName in FilterConfig class.
Your JSON structure is different from that of FilterConfig.
I tried to run the code with the above changes and its working fine.
case class FilterConfig(inputDFName: String,conditions: String)
import com.google.gson.Gson;
def readDataFiltr(conf:String): FilterConfig ={
val gson = new Gson()
gson.fromJson(conf,classOf[FilterConfig])
}
val x = readDataFiltr("{\"inputDFName\": \"testInput\", \"conditions\": \"site_type = 'micro'\"}")
println(x.inputDFName)
println(x.conditions)
Please let me know if this is not clear.
Thanks,
Vivek

Related

PlayJSON in Scala

I am trying to familiarize myself with the PlayJSON library. I have a JSON formatted file like this:
{
"Person": [
{
"name": "Jonathon",
"age": 24,
"job": "Accountant"
}
]
}
However, I'm having difficulty with parsing it properly due to the file having different types (name is a String but age is an Int). I could technically make it so the age is a String and call .toInt on it later but for my purposes, it is by default an integer.
I know how to parse some of it:
import play.api.libs.json.{JsValue, Json}
val parsed: JsValue = Json.parse(jsonFile) //assuming jsonFile is that entire JSON String as shown above
val person: List[Map[String, String]] = (parsed \ "Person").as[List[Map[String, String]]]
Creating that person value throws an error. I know Scala is a strongly-typed language but I'm sure there is something I am missing here. I feel like this is an obvious fix too but I'm not quite sure.
The error produced is:
JsResultException(errors:List(((0)/age,List(JsonValidationError(List(error.expected.jsstring),WrappedArray())))
The error you are having, as explained in the error you are getting, is in casting to the map of string to string. The data you provided does not align with it, because the age is a string. If you want to keep in with this approach, you need to parse it into a type that will handle both strings and ints. For example:
(parsed \ "Person").validate[List[Map[String, Any]]]
Having said that, as #Luis wrote in a comment, you can just use case class to parse it. Lets declare 2 case classes:
case class JsonParsingExample(Person: Seq[Person])
case class Person(name: String, age: Int, job: String)
Now we will create a formatter for each of them on their corresponding companion object:
object Person {
implicit val format: OFormat[Person] = Json.format[Person]
}
object JsonParsingExample {
implicit val format: OFormat[JsonParsingExample] = Json.format[JsonParsingExample]
}
Now we can just do:
Json.parse(jsonFile).validate[JsonParsingExample]
Code run at Scastie.

Making json files in Scala

I am working on a Scala app. I have a method that gives me JSON and I convert it to string using toString as follows:
def myjson(fileName:String){
val myJson = myData.getJsonData().toString
}
Here getJsonData() will give me a .json. I want to write this .json into a file and save this .json in resources section in my project. Format of the file should be ".json". Name of the file is the one which I am getting in above method. How can I do that?
One approach would be as follow
import java.nio.file.{Paths, Files}
import java.nio.charset.StandardCharsets
def myjson(fileName:String){
val myJson = myData.getJsonData().toString
val path = s"/user/myProject/..../resources/$fileName"
Files.write(Paths.get(path), myJson.getBytes(StandardCharsets.UTF_8))
}
I understand that fileName: String will be something like filename.json

How to return JSON instead of Case Class in akka-Http

I created a route to stream a list of case class in JSON. But if I use ByteString, the case class is printed instead of JSON
def streamRoute: Route = pathEndOrSingleSlash {
val byteString = new LocalFileParser(config).importFromFiles.map(phoneNumber => ByteString(phoneNumber.toString + "\n"))
complete(HttpEntity(ContentTypes.`application/json`, byteString))
}
// RESULT: PhoneNumber(+35799000123,Some(357),Some(Cyprus),Some(Cytamobile-Vodafone),Some(MOBILE))
If I just use complete(new LocalFileParser(config).importFromFiles), then this is giving me JSON. Is the second method good for streaming chunked response? If no, How can I fix first method to return JSON instead of Case Class
With the Json.toJson(result) method you can send your result as a JSON,
In your case something like this : val byteString = new LocalFileParser(config).importFromFiles.map(phoneNumber => Ok(Json.toJson(phoneNumber)))
Hope this helps
PS: Ok is probably the HTTP code you want to send there
Considering you're already using Circe, you can simplify by adding this library into your project:
"de.heikoseeberger" %% "akka-http-circe" % "<latest-version>"
and importing these two classes in order to marshal your List[PhoneNumber] to an HttpResponse containing json:
import de.heikoseeberger.akkahttpcirce.ErrorAccumulatingCirceSupport._
import io.circe.generic.auto._
def streamRoute: Route = pathEndOrSingleSlash {
complete(new LocalFileParser(config).importFromFiles)
}

Klaxon Parsing of Nested Arrays

Im trying to parse this file with Klaxon, generally its going well, except I am totally not succeeding in parsing that subarray of features/[Number]/properties/
So my thought is to get the raw string of properties and to parse it seperately with Klaxon, though I dont succeed in that either. Apart from that I took many other approaches as well.
My code so far:
class Haltestelle(val type: String?, val totalFeatures: Int?, val features: Array<Any>?)
fun main(args: Array<String>) { // Main-Routine
val haltejsonurl = URL("http://online-service.kvb-koeln.de/geoserver/OPENDATA/ows?service=WFS&version=1.0.0&request=GetFeature&typeName=ODENDATA%3Ahaltestellenbereiche&outputFormat=application/json")
val haltestringurl = haltejsonurl.readText()
val halteklx = Klaxon().parse<Haltestelle>(haltestringurl)
println(halteklx?.type)
println(halteklx?.totalFeatures)
println(halteklx?.features)
halteklx?.features!!.forEach {
println(it)
}
I am aware that I am invoking features as an Array of Any, so the Output is just printing me java.lang.Object#blabla everytime. Though, using Array failes either.
Really spend hours in this, how would you go on this?
Regards of newbie
Here's how I did something similar in Kotlin. You can parse the response as a Klaxon JsonObject, then access the "features" element to parse all the array objects into a JsonArray of JsonObjects. This can be iterated over and cast with parseFromJsonObject<Haltestelle> in your example:
import com.beust.klaxon.JsonArray
import com.beust.klaxon.JsonObject
import com.beust.klaxon.Parser
import com.github.aivancioglo.resttest.*
val response : Response = RestTest.get("http://anyurlwithJSONresponse")
val myParser = Parser()
val data : JsonObject = myParser.parse(response.getBody()) as JsonObject
val allFeatures : JsonArray<JsonObject>? = response["features"] as JsonArray<JsonObject>?
for((index,obj) in allFeatures.withIndex()) {
println("Loop Iteration $index on each object")
val yourObj = Klaxon().parseFromJsonObject<Haltestelle>(obj)
}

Grails: Easy and efficient way to parse JSON from a Request

Please pardon me if this is a repeat question. I have been through some of the questions/answers with a similar requirement but somehow got a bit overwhelmed and confused at the same time. My requirement is:
I get a JSON string/object as a request parameter. ( eg: params.timesheetJSON )
I then have to parse/iterate through it.
Here is the JSON that my grails controller will be receiving:
{
"loginName":"user1",
"timesheetList":
[
{
"periodBegin":"2014/10/12",
"periodEnd":"2014/10/18",
"timesheetRows":[
{
"task":"Cleaning",
"description":"cleaning description",
"paycode":"payCode1"
},
{
"task":"painting",
"activityDescription":"painting description",
"paycode":"payCode2"
}
]
}
],
"overallStatus":"SUCCESS"
}
Questions:
How can I retrieve the whole JSON string from the request? Does request.JSON be fine here? If so, will request.JSON.timesheetJSON yield me the actual JSON that I want as a JSONObject?
What is the best way to parse through the JSON object that I got from the request? Is it grails.converters.JSON? Or is there any other easy way of parsing through? Like some API which will return the JSON as a collection of objects by automatically taking care of parsing. Or is programatically parsing through the JSON object the only way?
Like I said, please pardon me if the question is sounding vague. Any good references JSON parsing with grails might also be helpful here.
Edit: There's a change in the way I get the JSON string now. I get the JSON string as a request paramter.
String saveJSON // This holds the above JSON string.
def jsonObject = grails.converters.JSON.parse(saveJSON) // No problem here. Returns a JSONObject. I checked the class type.
def jsonArray = jsonArray.timesheetList // No problem here. Returns a JSONArray. I checked the class type.
println "*** Size of jsonArray1: " + jsonArray1.size() // Returns size 1. It seemed fine as the above JSON string had only one timesheet in timesheetList
def object1 = jsonArray[1] // This throws the JSONException, JSONArray[1] not found. I tried jsonArray.getJSONObject(1) and that throws the same exception.
Basically, I am looking to seamlessly iterate through the JSON string now.
I have wrote some code that explains how this can be done, that you can see below, but to be clear, first the answers to your questions:
Your JSON String as you wrote above will be the contents of your POST payload to the rest controller. Grails will use its data binding mechanism to bind the incomming data to a Command object that your should prepare. It has to have fields corresponding to the parameters in your JSON String (see below). After you bind your command object to your actual domain object, you can get all the data you want, by simply operating on fields and lists
The way to parse thru the JSON object is shown in my example below. The incomming request is esentially a nested map, with can be simply accessed with a dot
Now some code that illustrates how to do it.
In your controller create a method that accepts "YourCommand" object as input parameter:
def yourRestServiceMethod (YourCommand comm){
YourClass yourClass = new YourClass()
comm.bindTo(yourClass)
// do something with yourClass
// println yourClass.timeSheetList
}
The command looks like this:
class YourCommand {
String loginName
List<Map> timesheetList = []
String overallStatus
void bindTo(YourClass yourClass){
yourClass.loginName=loginName
yourClass.overallStatus=overallStatus
timesheetList.each { sheet ->
TimeSheet timeSheet = new TimeSheet()
timeSheet.periodBegin = sheet.periodBegin
timeSheet.periodEnd = sheet.periodEnd
sheet.timesheetRows.each { row ->
TimeSheetRow timeSheetRow = new TimeSheetRow()
timeSheetRow.task = row.task
timeSheetRow.description = row.description
timeSheetRow.paycode = row.paycode
timeSheet.timesheetRows.add(timeSheetRow)
}
yourClass.timeSheetList.add(timeSheet)
}
}
}
Its "bindTo" method is the key piece of logic that understands how to get parameters from the incomming request and map it to a regular object. That object is of type "YourClass" and it looks like this:
class YourClass {
String loginName
Collection<TimeSheet> timeSheetList = []
String overallStatus
}
all other classes that are part of that class:
class TimeSheet {
String periodBegin
String periodEnd
Collection<TimeSheetRow> timesheetRows = []
}
and the last one:
class TimeSheetRow {
String task
String description
String paycode
}
Hope this example is clear enough for you and answers your question
Edit: Extending the answer according to the new requirements
Looking at your new code, I see that you probably did some typos when writting that post
def jsonArray = jsonArray.timesheetList
should be:
def jsonArray = jsonObject.timesheetList
but you obviously have it properly in your code since otherwise it would not work, then the same with that line with "println":
jsonArray1.size()
shuold be:
jsonArray.size()
and the essential fix:
def object1 = jsonArray[1]
shuold be
def object1 = jsonArray[0]
your array is of size==1, the indexing starts with 0. // Can it be that easy? ;)
Then "object1" is again a JSONObject, so you can access the fields with a "." or as a map, for example like this:
object1.get('periodEnd')
I see your example contains errors, which lead you to implement more complex JSON parsing solutions.
I rewrite your sample to the working version. (At least now for Grails 3.x)
String saveJSON // This holds the above JSON string.
def jsonObject = grails.converters.JSON.parse(saveJSON)
println jsonObject.timesheetList // output timesheetList structure
println jsonObject.timesheetList[0].timesheetRows[1] // output second element of timesheetRows array: [paycode:payCode2, task:painting, activityDescription:painting description]