将当前时间（dt）从秒转换为实时格式（小时和分钟）

Question

I was able to display some weather data on my app using retrofit from a JSON response, but the current time(dt), sunrise, and sunset displays on my textviews as seconds ie 1612730263. So I need to convert the time to a real-time format(hour and minute) eg 9:30 PM. Disclaimer : Java: Date from unix timestamp and How to convert seconds to time format? doesn't work for me because my response is from an API. Therefore my question is not a duplicate.

My API response:

    {
   "lat":9.0765,
   "lon":7.3986,
   "timezone":"Africa/Lagos",
   "timezone_offset":3600,
   "current":{
      "dt":1612779720,
      "sunrise":1612763455,
      "sunset":1612805901,
      "temp":304.15,
      "feels_like":302.14,
      "pressure":1013,
      "humidity":33,
      "dew_point":286,
      "uvi":8.42,
      "clouds":42,
      "visibility":7000,
      "wind_speed":4.12,
      "wind_deg":100,
      "weather":[
         {
            "id":802,
            "main":"Clouds",
            "description":"scattered clouds",
            "icon":"03d"
         }
      ]
   }
}

My Retrofit call for the time in HomeActivity :

Retrofit retrofit = new Retrofit.Builder().baseUrl(BaseUrl).addConverterFactory(GsonConverterFactory.create()).build();
        WeatherService service = retrofit.create(WeatherService.class);
        Call<WeatherResponse> call = service.getCurrentWeatherData(lat, lon, AppId);
        call.enqueue(new Callback<WeatherResponse>() {

            @Override
            public void onResponse(@NonNull Call<WeatherResponse> call, @NonNull Response<WeatherResponse> response) {
                if (response.code() == 200) {
                    WeatherResponse weatherResponse = response.body();
                    assert weatherResponse != null;

                    assert response.body() != null;
// current time textview
                  time_field.setText(String.valueOf(response.body().getCurrent().getDt()));

My Retrofit call for the time & in FirstFragment :

Retrofit retrofit = new Retrofit.Builder().baseUrl(BaseUrl).addConverterFactory(GsonConverterFactory.create()).build();
                WeatherService service = retrofit.create(WeatherService.class);
                Call<WeatherResponse> call = service.getCurrentWeatherData(lat, lon, AppId);
                call.enqueue(new Callback<WeatherResponse>() {
                    @Override
                    public void onResponse(@NonNull Call<WeatherResponse> call, @NonNull Response<WeatherResponse> response) {
                        if (response.code() == 200) {
                            WeatherResponse weatherResponse = response.body();
                            assert weatherResponse != null;

                            assert response.body() != null; 
// sunrise & sunset time textviews                                                             
rise_time.setText(response.body().getCurrent().getSunrise() + " AM");                                
set_time.setText(response.body().getCurrent().getSunset() + " PM");

EDIT

WeatherResponse.java :

public class WeatherResponse {

    @SerializedName("lat")
    @Expose
    private Double lat;
    @SerializedName("lon")
    @Expose
    private Double lon;
    @SerializedName("timezone")
    @Expose
    private String timezone;
    @SerializedName("timezone_offset")
    @Expose
    private Integer timezoneOffset;
    @SerializedName("current")
    @Expose
    private Current current;

    public Double getLat() {
        return lat;
    }

    public void setLat(Double lat) {
        this.lat = lat;
    }

    public Double getLon() {
        return lon;
    }

    public void setLon(Double lon) {
        this.lon = lon;
    }

    public String getTimezone() {
        return timezone;
    }

    public void setTimezone(String timezone) {
        this.timezone = timezone;
    }

    public Integer getTimezoneOffset() {
        return timezoneOffset;
    }

    public void setTimezoneOffset(Integer timezoneOffset) {
        this.timezoneOffset = timezoneOffset;
    }

    public Current getCurrent() {
        return current;
    }

    public void setCurrent(Current current) {
        this.current = current;
    }

}

Current.java :

public class Current {

    @SerializedName("dt")
    @Expose
    private Integer dt;
    @SerializedName("sunrise")
    @Expose
    private Integer sunrise;
    @SerializedName("sunset")
    @Expose
    private Integer sunset;
    @SerializedName("temp")
    @Expose
    private Double temp;
    @SerializedName("feels_like")
    @Expose
    private Double feelsLike;
    @SerializedName("pressure")
    @Expose
    private Integer pressure;
    @SerializedName("humidity")
    @Expose
    private Integer humidity;
    @SerializedName("dew_point")
    @Expose
    private Double dewPoint;
    @SerializedName("uvi")
    @Expose
    private Double uvi;
    @SerializedName("clouds")
    @Expose
    private Integer clouds;
    @SerializedName("visibility")
    @Expose
    private Integer visibility;
    @SerializedName("wind_speed")
    @Expose
    private Double windSpeed;
    @SerializedName("wind_deg")
    @Expose
    private Integer windDeg;
    @SerializedName("weather")
    @Expose
    private List<Weather> weather = null;

    public Integer getDt() {
        return dt;
    }

    public void setDt(Integer dt) {
        this.dt = dt;
    }

    public Integer getSunrise() {
        return sunrise;
    }

    public void setSunrise(Integer sunrise) {
        this.sunrise = sunrise;
    }

    public Integer getSunset() {
        return sunset;
    }

    public void setSunset(Integer sunset) {
        this.sunset = sunset;
    }

    public Double getTemp() {
        return temp;
    }

    public void setTemp(Double temp) {
        this.temp = temp;
    }

    public Double getFeelsLike() {
        return feelsLike;
    }

    public void setFeelsLike(Double feelsLike) {
        this.feelsLike = feelsLike;
    }

    public Integer getPressure() {
        return pressure;
    }

    public void setPressure(Integer pressure) {
        this.pressure = pressure;
    }

    public Integer getHumidity() {
        return humidity;
    }

    public void setHumidity(Integer humidity) {
        this.humidity = humidity;
    }

    public Double getDewPoint() {
        return dewPoint;
    }

    public void setDewPoint(Double dewPoint) {
        this.dewPoint = dewPoint;
    }

    public Double getUvi() {
        return uvi;
    }

    public void setUvi(Double uvi) {
        this.uvi = uvi;
    }

    public Integer getClouds() {
        return clouds;
    }

    public void setClouds(Integer clouds) {
        this.clouds = clouds;
    }

    public Integer getVisibility() {
        return visibility;
    }

    public void setVisibility(Integer visibility) {
        this.visibility = visibility;
    }

    public Double getWindSpeed() {
        return windSpeed;
    }

    public void setWindSpeed(Double windSpeed) {
        this.windSpeed = windSpeed;
    }

    public Integer getWindDeg() {
        return windDeg;
    }

    public void setWindDeg(Integer windDeg) {
        this.windDeg = windDeg;
    }

    public List<Weather> getWeather() {
        return weather;
    }

    public void setWeather(List<Weather> weather) {
        this.weather = weather;
    }
}

Please I need the code provided to be linked to my app so that it will be easier to implement it. I have basic knowledge of dt conversion, but not from a weather API response. I think using my textviews to convert the data will be better(If there's any way you can use my textviews to do it)

Answer 1

It seems you need to obtain the right date patterns right from the information returned in the WeatherResponse and related classes.

For this purpose, you need to customize the Gson library you are using in your code to deserialize the information returned by the openweathermap API by Retrofit.

There are several ways to do this but, as far as you have the ability to modify the classes generated by jsonschema2pojo , I would suggest the following approach.

The idea consists basically in implement a custom Gson deserializer to handle the required transformation.

You can opt for implement this custom deserializer for the whole Current class but I think it will be easier to only handle the deserialization of the necessary fields.

For that purpose, first, let's create a new type; it will serve as a marker for the fields that require the custom deserialization. For example:

public class PrettyTime {

  private String value;

  public PrettyTime() {
  }

  public PrettyTime(String value) {
    this.value = value;
  }

  public String getValue() {
    return value;
  }

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

  @Override
  public String toString() {
    return getValue();
  }
}

Apply this marker to the fields you need the conversion in the Current class:

public class Current {

  @SerializedName("dt")
  @Expose
  private PrettyTime dt;
  @SerializedName("sunrise")
  @Expose
  private PrettyTime sunrise;
  @SerializedName("sunset")
  @Expose
  private PrettyTime sunset;

  // The rest of the fields and setters and getters

  public PrettyTime getDt() {
    return dt;
  }

  public void setDt(PrettyTime dt) {
    this.dt = dt;
  }

  public PrettyTime getSunrise() {
    return sunrise;
  }

  public void setSunrise(PrettyTime sunrise) {
    this.sunrise = sunrise;
  }

  public PrettyTime getSunset() {
    return sunset;
  }

  public void setSunset(PrettyTime sunset) {
    this.sunset = sunset;
  }
  
}

Next, let's create the custom deserializer:

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;

import java.lang.reflect.Type;
import java.text.SimpleDateFormat;
import java.util.Date;

public class PrettyTimeDeserializer implements JsonDeserializer<PrettyTime> {
  // Modify the date pattern as you consider appropriate
  private static final SimpleDateFormat HMM = new SimpleDateFormat("hh:mm");

  public PrettyTime deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
      throws JsonParseException {
    final long seconds = json.getAsJsonPrimitive().getAsLong();
    final Date date = new Date(seconds * 1000);
    final String prettyFormatted = HMM.format(date);
    return new PrettyTime(prettyFormatted);
  }
}

Finally, integrate this deserializer in your code, both in the HomeActivity and FirstFragment classes:

Gson gson = new GsonBuilder()
  .registerTypeAdapter(PrettyTime.class, new PrettyTimeDeserializer())
  .create();

Retrofit retrofit = new Retrofit.Builder()
  .baseUrl(BaseUrl)
  // Please note the gson argument
  .addConverterFactory(GsonConverterFactory.create(gson))
  .build()
;

// The rest of your code

Answer 2

Just create a date object with that value as parameter:

java.util.Date time=new java.util.Date(((long)timeStamp)*1000);

As java is expecting milliseconds as a parameter, you need to multiply your value (in seconds) by 1000.

Answer 3

You can use Instant#ofEpochSecond to get the Instant which you can convert into ZonedDateTime for the specified timezone ID and then format the obtained ZonedDateTime using DateTimeFormatter .

import java.time.Instant;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Locale;

public class Main {
    public static void main(String[] args) {
        // Test
        System.out.println(
                "Sunrise date and time with timezone: " + getDateTimeWithTzString(1608529251L, "Africa/Lagos"));
        System.out.println("Sunrise date and time: " + getDateTimeString(1608529251L, "Africa/Lagos"));
        System.out.println("Sunrise time: " + getTimeString(1608529251L, "Africa/Lagos"));
        System.out.println("Date: " + getDateString(1608529251L, "Africa/Lagos"));
    }

    static String getDateTimeWithTzString(long epochSecond, String strTz) {
        ZoneId zoneId = ZoneId.of(strTz);
        Instant instant = Instant.ofEpochSecond(epochSecond);
        ZonedDateTime zdt = instant.atZone(zoneId);
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd h:m:s a '['VV']'", Locale.ENGLISH);
        return zdt.format(dtf);
    }

    static String getDateTimeString(long epochSecond, String strTz) {
        ZoneId zoneId = ZoneId.of(strTz);
        Instant instant = Instant.ofEpochSecond(epochSecond);
        ZonedDateTime zdt = instant.atZone(zoneId);
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd h:m:s a", Locale.ENGLISH);
        return zdt.format(dtf);
    }

    static String getTimeString(long epochSecond, String strTz) {
        ZoneId zoneId = ZoneId.of(strTz);
        Instant instant = Instant.ofEpochSecond(epochSecond);
        ZonedDateTime zdt = instant.atZone(zoneId);
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("h:m:s a", Locale.ENGLISH);
        return zdt.format(dtf);
    }

    static String getDateString(long epochSecond, String strTz) {
        ZoneId zoneId = ZoneId.of(strTz);
        Instant instant = Instant.ofEpochSecond(epochSecond);
        ZonedDateTime zdt = instant.atZone(zoneId);
        return zdt.toLocalDate().toString();
    }
}

Output:

Sunrise date and time with timezone: 2020-12-21 6:40:51 AM [Africa/Lagos]
Sunrise date and time: 2020-12-21 6:40:51 AM
Sunrise time: 6:40:51 AM
Date: 2020-12-21

Learn more about the modern date-time API from Trail: Date Time .

For any reason, if you have to stick to Java 6 or Java 7, you can use ThreeTen-Backport which backports most of the java.time functionality to Java 6 & 7. If you are working for an Android project and your Android API level is still not compliant with Java-8, check Java 8+ APIs available through desugaring and How to use ThreeTenABP in Android Project .

Answer 4

String timezone = "Africa/Lagos"; // "timezone":"Africa/Lagos"
long dt = 1612779720L; // "dt":1612779720
long sunriseTime = 1612763455L; // "sunrise":1612763455
long sunsetTime = 1612805901L; // "sunset":1612805901
double temp = 304.15D; // "temp":304.15 (in Kelvin).
        
SimpleDateFormat sdf = new SimpleDateFormat("h:mm aa"); // h:mm AM/PM (hh:mm aa == hh:mm AM/PM).
sdf.setTimeZone(TimeZone.getTimeZone(timezone));
        
// current local time
String time = sdf.format(new Date(dt));
// sunrise
String sunrise = sdf.format(new Date(sunriseTime));
// sunset
String sunset = sdf.format(new Date(sunsetTime));
// temperature in Celcius
String celcius = String.format("%.2f °C", temp - 273.16D);
// temperature in Fahrenheit
String fahrenheit = String.format("%.2f °F", ((temp - 273D) * 9D/5D) + 32D);
        
System.out.println(time); //4:59 PM
System.out.println(sunrise); //4:59 PM
System.out.println(sunset); //5:00 PM
System.out.println(celcius); //30.99 °C
System.out.println(fahrenheit); //88.07 °F