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尝试检索JSON数组时，Retrofit2 GET请求在列表中返回一些空条目

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JSON数据：

2647ms 
360ms
10440ms

Api界面：

[
  {
    "ID": 47,"lat": 20.2,"lon": 18.04308,"alt": "100","location": "Location 001","meinOrt": "Ort1","meineBeschreibung": "wald","satNr": "0"
  },{
    "ID": 47,"lat": 50,"lon": 28.04308,"alt": "134.5","location": "Location 002","meinOrt": "Ort2","meineBeschreibung": "wald2","lat": 49.07458166666667,"lon": 16.04308,"location": "Location 003","meinOrt": "Ort3","lat": 46.07458166666667,"lon": 33.04308,"alt": "134","location": "Location 004","meinOrt": "Ort4","lat": 45,"lon": 24.2,"location": "Location 005","meinOrt": "Ort5","satNr": "0"
  }
]

Entries.java 

    @GET("get_entries.php")
    Call<List<Entries>> getEntries();

Orte.java（已进行调用）：

class Entries {

    private int id;
    private String latitude;
    private String longitude;
    private String location;
    private String altitude;
    private String meinOrt;
    private String meineBeschreibung;
    private String myDatetime;



    public Entries(int id,String latitude,String longitude,String location,String altitude,String meinOrt,String meineBeschreibung,String myDatetime) {
        this.id = id;
        this.latitude = latitude;
        this.longitude = longitude;
        this.location = location;
        this.altitude = altitude;
        this.meinOrt = meinOrt;
        this.meineBeschreibung = meineBeschreibung;
        this.myDatetime = myDatetime;
    }

    public int getID() {
        Log.d("DEBUG","in getID = " + latitude );
        return id;
    }

    public String getlatitude() {
        return latitude;
    }

    public String getlongitude() {
        return longitude;
    }

    public String getlocation() {
        return location;
    }

    public String getaltitude() {
        return altitude;
    }

    public String getmeinOrt() {
        return meinOrt;
    }

    public String getmeineBeschreibung() {
        return meineBeschreibung;
    }

    public String getmyDatetime() {
        return myDatetime;
    }
}

Logcat：

    private void getEntries() {

        textViewResult = findViewById(R.id.text_view_result);

        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl("http://myBaseUrlexample.de/api/")
                .addConverterFactory(GsonConverterFactory.create())
                .build();

        JsonPlaceHolderApi jsonPlaceHolderApi = retrofit.create(JsonPlaceHolderApi.class);
        Log.d("DEBUG","--> API CREATE  = " + jsonPlaceHolderApi );

        Call<List<Entries>> call = jsonPlaceHolderApi.getEntries();
        Log.d("DEBUG","--> create call  = " + call );

        call.enqueue(new Callback<List<Entries>>() {
            @Override
            public void onResponse(Call<List<Entries>> call,Response<List<Entries>> response) {
                Log.d("DEBUG","--> on response  = " + call );
                if (!response.isSuccessful()) {
                    textViewResult.setText("Code: " + response.code());
                    return;
                }


                List<Entries> alleEintraege = response.body();

                Log.d("DEBUG","--> API CREATE  = " + alleEintraege );

                for (Entries einzeleintrag : alleEintraege) {

                    String content = "";
                    content += "ID: " + einzeleintrag.getID() + "\n";
                    content += "Lat: " + einzeleintrag.getlatitude() + "\n";
                    content += "Lon: " + einzeleintrag.getlongitude() + "\n";
                    content += "Ort: " + einzeleintrag.getmeinOrt() + "\n";
                    //content += "Entfernung: " + distance + "\n";
                    content += "Location: " + einzeleintrag.getlocation() + "\n";
                    content += "Höhe: " + einzeleintrag.getmyDatetime() + "\n";
                    content += "Beschreibung: " + einzeleintrag.getmeineBeschreibung() + "\n\n";

                    textViewResult.append(content);
                }
            }

            @Override
            public void onFailure(Call<List<Entries>> call,Throwable t) {
                textViewResult.setText(t.getMessage());
            }
        });
    }

手机结果：

  

ID：0纬度：空Lon：空Ort：Ort1位置：Location001Höhe：空   Beschreibung：瓦尔德

     

ID：0纬度：空Lon：空Ort：Ort2位置：Location002Höhe：空   Beschreibung：wald2

     

ID：0纬度：空Lon：空Ort：Ort3位置：Location003Höhe：空   Beschreibung：瓦尔德

     

ID：0纬度：空Lon：空Ort：Ort4位置：Location004Höhe：空   Beschreibung：瓦尔德

     

ID：0纬度：空Lon：空Ort：Ort5位置：Location005Höhe：空   Beschreibung：waldschreibung：瓦尔德

因此，某些条目的响应很好，而某些条目只是为空，非常感谢您能正确地获得所有帮助，谢谢。

luckyxiaoli 回答：尝试检索JSON数组时，Retrofit2 GET请求在列表中返回一些空条目

在模型中使用Gson @SerializedName("")将密钥与json匹配

@SerializedName("ID")
private int id;
@SerializedName("lat")
private String latitude;
@SerializedName("lon")
private String longitude;
@SerializedName("location")
private String location;
@SerializedName("alt")
private String altitude;
@SerializedName("meinOrt")
private String meinOrt;
@SerializedName("meineBeschreibung")
private String meineBeschreibung;
@SerializedName("satNr")
private String myDatetime;
,

使用jsonschema2pojo生成模型，该模型应为：

应该是“ ID”而不是“ id” 

public class Example {

@SerializedName("ID")
@Expose
private Integer iD;
@SerializedName("lat")
@Expose
private Integer lat;
@SerializedName("lon")
@Expose
private Double lon;
@SerializedName("alt")
@Expose
private String alt;
@SerializedName("location")
@Expose
private String location;
@SerializedName("meinOrt")
@Expose
private String meinOrt;
@SerializedName("meineBeschreibung")
@Expose
private String meineBeschreibung;
@SerializedName("satNr")
@Expose
private String satNr;

public Integer getID() {
return iD;
}

public void setID(Integer iD) {
this.iD = iD;
}

public Integer getLat() {
return lat;
}

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

public Double getLon() {
return lon;
}

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

public String getAlt() {
return alt;
}

public void setAlt(String alt) {
this.alt = alt;
}

public String getLocation() {
return location;
}

public void setLocation(String location) {
this.location = location;
}

public String getMeinOrt() {
return meinOrt;
}

public void setMeinOrt(String meinOrt) {
this.meinOrt = meinOrt;
}

public String getMeineBeschreibung() {
return meineBeschreibung;
}

public void setMeineBeschreibung(String meineBeschreibung) {
this.meineBeschreibung = meineBeschreibung;
}

public String getSatNr() {
return satNr;
}

public void setSatNr(String satNr) {
this.satNr = satNr;
}

}
,

问题是Retrofit使用GsonConvertor将（JSON对象转换为POJO）序列化。为此，您应该在创建的JSON对象和POJO对象中使用相同的名称。

作为@ Md.Asaduzzaman答案，您可以使用@SerializedName("---")，也可以重命名POJO类成员以与JSON响应匹配。

i.e latitude to lat

androidgetjsonnullretrofit2
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