How to deserialize ThreeTen LocalDateTime in Retrofit?

Question

I'm trying to deserialise this class in Retrofit:

data class Measurement(val id: Long, val value: Float, val dateTime: LocalDateTime, val trashCanId: Long) : Parcelable {
    companion object {
        @JvmField val CREATOR: Parcelable.Creator<Measurement> = object : Parcelable.Creator<Measurement> {
            override fun createFromParcel(source: Parcel): Measurement = Measurement(source)
            override fun newArray(size: Int): Array<Measurement?> = arrayOfNulls(size)
        }
    }

    constructor(source: Parcel) : this(source.readLong(), source.readFloat(), source.readSerializable() as LocalDateTime, source.readLong())

    override fun describeContents() = 0

    override fun writeToParcel(dest: Parcel?, flags: Int) {
        dest?.writeLong(id)
        dest?.writeFloat(value)
        dest?.writeSerializable(dateTime)
        dest?.writeLong(trashCanId)
    }

}

As you can see, I'm using LocalDateTime, it's from ThreeTen. Well, I receive this from my server

    {
        "id": 1,
        "value": 50.6,
        "dateTime": {
          "hour": 2,
          "minute": 6,
          "second": 9,
          "nano": 0,
          "dayOfYear": 308,
          "dayOfWeek": "THURSDAY",
          "month": "NOVEMBER",
          "dayOfMonth": 3,
          "year": 2016,
          "monthValue": 11,
          "chronology": {
            "id": "ISO",
            "calendarType": "iso8601"
          }
        }
      }

Well, but my dateTime is always Null so I believe that Retrofit doesnt know how parse the Data, or am I missing something?

Is there any good workaround?

Any help is appreciated!

score 1 · Answer 1 · answered Nov 07 '16 at 06:05

Add this gradle first

 compile 'com.google.code.gson:gson:2.8.0'

Then add this class to hold the json response,

public class DemoResponse {
@com.google.gson.annotations.SerializedName("id")
public int id;
@com.google.gson.annotations.SerializedName("value")
public double value;

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public double getValue() {
    return value;
}

public void setValue(double value) {
    this.value = value;
}

public Datetime getDatetime() {
    return datetime;
}

public void setDatetime(Datetime datetime) {
    this.datetime = datetime;
}

@com.google.gson.annotations.SerializedName("dateTime")
public Datetime datetime;

public static class Chronology {
    @com.google.gson.annotations.SerializedName("id")
    public String id;
    @com.google.gson.annotations.SerializedName("calendarType")
    public String calendartype;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getCalendartype() {
        return calendartype;
    }

    public void setCalendartype(String calendartype) {
        this.calendartype = calendartype;
    }
}

public static class Datetime {
    @com.google.gson.annotations.SerializedName("hour")
    public int hour;
    @com.google.gson.annotations.SerializedName("minute")
    public int minute;
    @com.google.gson.annotations.SerializedName("second")
    public int second;
    @com.google.gson.annotations.SerializedName("nano")
    public int nano;
    @com.google.gson.annotations.SerializedName("dayOfYear")
    public int dayofyear;
    @com.google.gson.annotations.SerializedName("dayOfWeek")
    public String dayofweek;
    @com.google.gson.annotations.SerializedName("month")
    public String month;
    @com.google.gson.annotations.SerializedName("dayOfMonth")
    public int dayofmonth;
    @com.google.gson.annotations.SerializedName("year")
    public int year;
    @com.google.gson.annotations.SerializedName("monthValue")
    public int monthvalue;
    @com.google.gson.annotations.SerializedName("chronology")
    public Chronology chronology;

    public int getHour() {
        return hour;
    }

    public void setHour(int hour) {
        this.hour = hour;
    }

    public int getMinute() {
        return minute;
    }

    public void setMinute(int minute) {
        this.minute = minute;
    }

    public int getSecond() {
        return second;
    }

    public void setSecond(int second) {
        this.second = second;
    }

    public int getNano() {
        return nano;
    }

    public void setNano(int nano) {
        this.nano = nano;
    }

    public int getDayofyear() {
        return dayofyear;
    }

    public void setDayofyear(int dayofyear) {
        this.dayofyear = dayofyear;
    }

    public String getDayofweek() {
        return dayofweek;
    }

    public void setDayofweek(String dayofweek) {
        this.dayofweek = dayofweek;
    }

    public String getMonth() {
        return month;
    }

    public void setMonth(String month) {
        this.month = month;
    }

    public int getDayofmonth() {
        return dayofmonth;
    }

    public void setDayofmonth(int dayofmonth) {
        this.dayofmonth = dayofmonth;
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        this.year = year;
    }

    public int getMonthvalue() {
        return monthvalue;
    }

    public void setMonthvalue(int monthvalue) {
        this.monthvalue = monthvalue;
    }

    public Chronology getChronology() {
        return chronology;
    }

    public void setChronology(Chronology chronology) {
        this.chronology = chronology;
    }
    }
    }

Then you can assign the response from retrofit to the object of this class, and retrieve the values using the setters.

score 1 · Accepted Answer · answered Nov 09 '16 at 15:13

Bsed on Manoj Frekzz answer, I found my solution...

First I created a DateTimeDto.

data class DateTimeDto(val dayOfYear : Int, val dayOfWeek : String, val month : String, val dayOfMonth : Int,
                       val year : Int, val monthValue : Int, val hour : Int, val minute : Int, val second : Int,
                       val nano : Int, val chronology : Chronology)



fun toDateTime () : LocalDateTime{
     return LocalDateTime.of(year, monthValue, dayOfMonth, hour, minute)
}

And I changed the signature of the interface from:

@GET("trashCan")

fun getLocalDateTime() : Observable<List<LocalDateTime>>

To:

@GET("trashCan")

fun getLocalDateTime() : Observable<List<DateTimeDto>>

Then, in my Observer I did that:

ServiceGenerator.createService(ApiClient::class.java)
                .getLocalDateTime
                .map { it.map { it.toLocalDateTime() } }

And it worked just fine... It would be nicer if I Retrofit could deserialize it automatically, but this is a good workaround

How to deserialize ThreeTen LocalDateTime in Retrofit?

2 Answers2