Android-当我认为不是Null的对象设置TextView的文本时，我收到Null对象引用错误。

Question

标题表明，当将JSON信息解析到同样位于Fragment内的文本视图中时，我在Android Studio中收到一个空指针异常。

错误日志：

   java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.test.test.Model.OpenWeatherMap.getName()' on a null object reference
    at com.test.test.Tab1Fragment$GetWeather.onPostExecute(Tab1Fragment.java:184)
    at com.test.test.Tab1Fragment$GetWeather.onPostExecute(Tab1Fragment.java:150)
    at android.os.AsyncTask.finish(AsyncTask.java:695)
    at android.os.AsyncTask.access$600(AsyncTask.java:180)
    at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:193)
    at android.app.ActivityThread.main(ActivityThread.java:6669)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

所以我收到了Null异常，但是我不认为对象为Null？

发生错误的行：

txtCity.setText(String.format("%s, %s",openWeatherMap.getName(), openWeatherMap.getSys().getCountry()));

        txtLastUpdate.setText(String.format("Refreshed: %s", Common.getDateNow()));
        txtDescription.setText(String.format("%s", openWeatherMap.getWeather().get(0).getDescription()));
        txtHumidity.setText(String.format("%d%%", openWeatherMap.getMain().getHumidity()));
        txtTime.setText(String.format("%s/%s", Common.unixTimeStampToDateTime(openWeatherMap.getSys().getSunrise()),Common.unixTimeStampToDateTime(openWeatherMap.getSys().getSunset())));
        txtCelcius.setText(String.format("%.2f °C", openWeatherMap.getMain().getTemp()));
        Picasso.with(getActivity())
                .load(Common.getImage(openWeatherMap.getWeather().get(0).getIcon()))
                .into(imageView);

我的模型类文件：

    import java.util.List;

public class OpenWeatherMap {
    private Coord cood;
    private List<Weather> weather;
    private String base;
    private Main main;
    private Wind wind;
    private Rain rain;
    private Clouds clouds;
    private int dt;
    private Sys sys;
    private int id;
    private String name;
    private int cod;

    public OpenWeatherMap() {
    }

    public OpenWeatherMap(Coord cood, List<Weather> weatherList, String base, Main main, Wind wind, Rain rain, Clouds clouds, int dt, Sys sys, int id, String name, int cod) {
        this.cood = cood;
        this.weather = weatherList;
        this.base = base;
        this.main = main;
        this.wind = wind;
        this.rain = rain;
        this.clouds = clouds;
        this.dt = dt;
        this.sys = sys;
        this.id = id;
        this.name = name;
        this.cod = cod;
    }

    public Coord getCood() {
        return cood;
    }

    public void setCood(Coord cood) {
        this.cood = cood;
    }

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

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

    public String getBase() {
        return base;
    }

    public void setBase(String base) {
        this.base = base;
    }

    public Main getMain() {
        return main;
    }

    public void setMain(Main main) {
        this.main = main;
    }

    public Wind getWind() {
        return wind;
    }

    public void setWind(Wind wind) {
        this.wind = wind;
    }

    public Rain getRain() {
        return rain;
    }

    public void setRain(Rain rain) {
        this.rain = rain;
    }

    public Clouds getClouds() {
        return clouds;
    }

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

    public int getDt() {
        return dt;
    }

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

    public Sys getSys() {
        return sys;
    }

    public void setSys(Sys sys) {
        this.sys = sys;
    }



    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

所以getName（）不应该发回空指针异常，这是正确的吗？错误线下方的线是否也会与错误线一起发生？我似乎无法理解为什么出现此错误？

我认为Model Class文件中的信息应该发送回JSON信息以解析到文本视图。

我正在遵循一个教程来学习将JSON信息解析到应用程序中，并且还尝试将信息发送到Fragment View。我在网上找到的大多数答案和讨论似乎都在讨论上面的内容，没有任何片段，但我相信仍然可以。