android - gson 中的 java.lang.StackOverflowError

Question

在 MVP Structure 中构建我的应用程序时，我遇到了一个问题，当我使用 Retrofit 调用 Web 服务以响应成功时
我将整个数据传递到 json 字符串中，所以它会促使我这样做。

我的原木猫:

 FATAL EXCEPTION: main java.lang.StackOverflowError
     at java.lang.AbstractStringBuilder.append0(AbstractStringBuilder.java:147)
     at java.lang.StringBuffer.append(StringBuffer.java:219)
     at java.io.StringWriter.write(StringWriter.java:147)
     at java.io.StringWriter.append(StringWriter.java:199)
     at java.io.StringWriter.append(StringWriter.java:30)
     at com.google.gson.stream.JsonWriter.beforeValue(JsonWriter.java:651)
     at com.google.gson.stream.JsonWriter.open(JsonWriter.java:325)
     at com.google.gson.stream.JsonWriter.beginObject(JsonWriter.java:308)
     at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.write(MapTypeAdapterFactory.java:205)
     at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.write(MapTypeAdapterFactory.java:145)
     at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69)
     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125)
     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243)
     at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
     at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69)
     at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.write(MapTypeAdapterFactory.java:208)
     at com.google.gson.internal.bind.MapTypeAdapterFactory$Adapter.write(MapTypeAdapterFactory.java:145)
     at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69)
     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:125)
     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:243)
     at com.google.gson.internal.bind.ObjectTypeAdapter.write(ObjectTypeAdapter.java:107)
     at com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:69)

这是我的改造 API 调用:

//API Call for Pitch
public void pitch() {
    services
        .getAPI()
        .pitchList()
        .enqueue(new Callback<PitchList_Res>() {
            @Override
            public void onResponse(Call<PitchList_Res> call, Response<PitchList_Res> response) {
                if (!response.body().getdATA().isEmpty()) {
                    Gson gson1=new Gson();
                    String json = gson1.toJson(response);
                    mListener.pitch(json);
                }
            }

            @Override
            public void onFailure(Call<PitchList_Res> call, Throwable t) {
                call.cancel();
                Toast.makeText(context, R.string.error, Toast.LENGTH_SHORT).show();
            }
        });
}

这是我收到响应的主要 Activity :

//Response of Pitch
@Override
public void pitch(String response_pitch) {

    editor.putString(Preference_Data.PITCH_RESPONSE, response_pitch);
    editor.commit();
    PitchList_Res pitchList_res = gson.fromJson(response_pitch, PitchList_Res.class);
    pitchlist.addAll(pitchList_res.getdATA());

    for (int i = 0; i < pitchlist.size(); i++) {

        View pitchview = getLayoutInflater().inflate(
                R.layout.textviewlayout, null);
        final TextView tvtitle = (TextView) pitchview
                .findViewById(R.id.tv_title);

        String id = pitchlist.get(i).getpITCHTYPEID().toString();
        tvtitle.setId(Integer.valueOf(id));

        tvtitle.setText(pitchlist.get(0).getpITCHSHORT().toString());
        tvtitle.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                if (stPitchSelectionID != -1) {
                    findViewById(stPitchSelectionID)
                            .setBackgroundResource(
                                    R.drawable.btn_bg);
                }
                if (stPitchSelectionID == v.getId()) {
                    stPitchSelectionID = -1;
                    tvtitle.setBackgroundResource(R.drawable.btn_bg);
                    pitchid = "0";

                } else {
                    stPitchSelectionID = v.getId();
                    tvtitle.setBackgroundResource(R.drawable.btn_bg_select);

                    pitchid = String.valueOf(stPitchSelectionID)
                            .substring(1);

                }
            }
        });
    }
}

从 Setdefaultvalue() 我正在检查我对 Activity 的响应:

public void Setdefaultvalue() {
    llpitchcontainer.removeAllViews();
    llbatresultcontainer.removeAllViews();
    llpitchresultcontainer.removeAllViews();
    llscoringcontainer.removeAllViews();
    etspeed.setText(65 + "");
    tvhh.setBackgroundResource(R.drawable.no_toggle);

    String response_pitch=pref.getString(Preference_Data.PITCH_RESPONSE,"");

   if (response_pitch.equalsIgnoreCase("")) {
        mainScoutPresenter.pitch();
       Log.e("Pitch_if","Pitch_if");
    } else {
           pitch(response_pitch);
           Log.e("Pitch_else", "Pitch_else");
   }
}

这是我的两个模型类:(PitchList_Res)

public class PitchList_Res implements Serializable {


    @SerializedName("DATA")
    @Expose
    private List<PitchList_Data> dATA = null;

    public List<PitchList_Data> getdATA() {
        return dATA;
    }

    public void setdATA(List<PitchList_Data> dATA) {
        this.dATA = dATA;
    }
}

PitchList_Data.java

public class PitchList_Data implements Serializable {

    @SerializedName("PITCHTYPEID")
    @Expose
    private Integer pITCHTYPEID;
    @SerializedName("PITCHFULL")
    @Expose
    private String pITCHFULL;
    @SerializedName("PITCHSHORT")
    @Expose
    private String pITCHSHORT;

    public Integer getpITCHTYPEID() {
        return pITCHTYPEID;
    }

    public void setpITCHTYPEID(Integer pITCHTYPEID) {
        this.pITCHTYPEID = pITCHTYPEID;
    }

    public String getpITCHFULL() {
        return pITCHFULL;
    }

    public void setpITCHFULL(String pITCHFULL) {
        this.pITCHFULL = pITCHFULL;
    }

    public String getpITCHSHORT() {
        return pITCHSHORT;
    }

    public void setpITCHSHORT(String pITCHSHORT) {
        this.pITCHSHORT = pITCHSHORT;
    }
}

Answer 1

I was getting the same problem & found that error is due to the variables in the class of type Object.

我正在解析一个包含内部对象的 java 类对象，其中一些包含 Object 类型的变量。由于 Gson 库无法解析该数据。

我已经删除了变量的对象类型声明，问题得到了解决。

I think Gson library is unable to parse the java object to json if java object contains some variable that is of generic type(like Object Type in my case).

public class HatchRetailer {
    private int id;
    private String name;
    private String purchaseLink;
    private String purchaseLinkDirect;
    private String logo;
    private String currency;
    private double price;
    private String stockInfo;
    private int stockCount;
    private String sourceDate;
    private String businessId;

//  As per my understanding Gson library is not able to parse variable of type Object
//  private Object marketFocus;
//  private Object group;

//  Setters & Getters
}