使用改造从 api 获取数据时出错

Posted 2023-03-22

【中文标题】使用改造从 api 获取数据时出错

【英文标题】：Error while fetching the data from api using retrofit

【发布时间】：2020-07-20 17:27:09

【问题描述】：

这是我的 json 格式的数据 我很困惑如何使用改造来获取嵌套数组/对象数据

 [
  
    "state": "Kerala",
    "districtData": [
      
        "district": "Thrissur",
        "confirmed": 12,
        "lastupdatedtime": "",
        "delta": 
          "confirmed": 0
        
      ,
      
        "district": "Alappuzha",
        "confirmed": 3,
        "lastupdatedtime": "",
        "delta": 
          "confirmed": 0
        
      ,
      
        "district": "Kasaragod",
        "confirmed": 156,
        "lastupdatedtime": "",
        "delta": 
          "confirmed": 0
        
      ,
    ]
  
]


    My Resopnse Class:--
public class StateDistrictResponse

    private String state;
    private DistrictDataModal[] districtData;

    public String getState() 
        return state;
    

    public void setState(String state) 
        this.state = state;
    

    public DistrictDataModal[] getDistrictData() 
        return districtData;
    

    public void setDistrictData(DistrictDataModal[] districtData) 
        this.districtData = districtData;
    

    public StateDistrictResponse(String state, DistrictDataModal[] districtData) 
        this.state = state;
        this.districtData = districtData;
    

DistrictDataModal的POJO CLASS/MODal CLass::-

 public class DistrictDataModal
    
        private String district;
        private String confirmed;
        private String lastupdatedtime;
        private DeltaModal delta;

        public String getDistrict() 
            return district;
        

        public void setDistrict(String district) 
            this.district = district;
        

        public String getConfirmed() 
            return confirmed;
        

        public void setConfirmed(String confirmed) 
            this.confirmed = confirmed;
        

        public String getLastupdatedtime() 
            return lastupdatedtime;
        

        public void setLastupdatedtime(String lastupdatedtime) 
            this.lastupdatedtime = lastupdatedtime;
        

        public DeltaModal getDelta() 
            return delta;
        

        public void setDelta(DeltaModal delta) 
            this.delta = delta;
        

        public DistrictDataModal(String district, String confirmed, String lastupdatedtime, DeltaModal delta) 
            this.district = district;
            this.confirmed = confirmed;
            this.lastupdatedtime = lastupdatedtime;
            this.delta = delta;
        
    

这里是我的对象类 Delta

 public class DeltaModal
    
        private String confirmed;

        public String getConfirmed() 
            return confirmed;
        

        public void setConfirmed(String confirmed) 
            this.confirmed = confirmed;
        

        public DeltaModal(String confirmed) 
            this.confirmed = confirmed;
        
    

这里是改造代码，我不明白如何获取对象的数据：-

private void getStateDistrict()
    

        Retrofit retrofit= new Retrofit.Builder()
                .baseUrl(Apis.ROOT)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        Apis request=retrofit.create(Apis.class);

        Call<StateDistrictResponse> call=request.getState_Distric_Wise();

        call.enqueue(new Callback<StateDistrictResponse>() 
            @Override
            public void onResponse(Call<StateDistrictResponse> call, Response<StateDistrictResponse> response) 



                if (response.isSuccessful())
                
                    try 
                        StateDistrictResponse response1=response.body();

                        Toast.makeText(StateDistrict.this, ""+response1.getDistrictData()[i].getDelta().getConfirmed(), Toast.LENGTH_SHORT).show();

                    
                    catch (Exception e)
                    
                        Toast.makeText(StateDistrict.this, "Ex:--"+e.toString(), Toast.LENGTH_LONG).show();
                    

                
                else
                
                    Toast.makeText(StateDistrict.this, "SOrry", Toast.LENGTH_SHORT).show();
                
            

            @Override
            public void onFailure(Call<StateDistrictResponse> call, Throwable t) 
                Toast.makeText(StateDistrict.this, "SOrry"+t.toString(), Toast.LENGTH_SHORT).show();

            
        );
    

【问题讨论】：

在 POJO 类变量中添加 @Expose 和 @SerializedName("<param name>") 注释。

【参考方案1】：

对于这类复杂的 json。我建议使用this perfect tool 可以将您的json 转换为结构良好的POJO。不管json多么复杂。

希望对你有帮助??

【参考方案2】：

在您的 StateDistrictResponse 类中：

private DistrictDataModal[] districtData;

应该是：

private List<DistrictDataModal> districtDate;

并很好地对齐 POJO。我还注意到根对象是一个数组？因此，请务必仔细检查，因为 json 以方括号开头。

【参考方案3】：

这个链接可能有用：

点击here！ 这很好用。