Gson stackoverflow Gson.fromJson

Question

我正在執行一個Web服務，這是我的回應，當我嘗試使用Gson庫將此JSONObject（org.json.JSONObject）轉換為特定對象時，我的應用程序崩潰了。 所以，我不知道為什么會這樣。 JSON：

{
"atributos": {
    "id": "1",
    "nombre": "Cliente",
    "descripcion": "Cliente",
    "version": "1"
},
"elementos": "[{
    "id": "1",
    "name" : "akira"
},
{
    "id": "4",
    "name" : "akira"
},
{
    "id": "5",
    "name" : "akira"
},
{
    "id": "6",
    "name" : "akira"
},
{
    "id": "7",
    "name" : "akira"
},
{
    "id": "8",
    "name" : "akira"
},
{
    "id": "9",
    "name" : "akira"
},
{
    "id": "10",
    "name" : "akira"
},
{
    "id": "11",
    "name" : "akira"
},
{
    "id": "12",
    "name" : "akira"
},
{
    "id": "13",
    "name" : "akira"
},
{
    "id": "14",
    "name" : "akira"
},
{
    "id": "15",
    "name" : "akira"
},
{
    "id": "16",
    "name" : "akira"
},
{
    "id": "17",
    "name" : "akira"
},
{
    "id": "18",
    "name" : "akira"
}]"
}

錯誤：

    java.lang.StackOverflowError
    05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:117)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.Gson.getAdapter(Gson.java:356)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.<init>(ReflectiveTypeAdapterFactory.java:82)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:81)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:118)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.Gson.getAdapter(Gson.java:356)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.<init>(ReflectiveTypeAdapterFactory.java:82)
05-02 17:50:56.166: E/AndroidRuntime(8130):     at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.createBoundField(ReflectiveTypeAdapterFactory.java:81)

Answer 1

當我驗證給你的json它有一些錯誤（示例Json給出的不是一個有效的json）。你的json在打開和關閉之前有“在元素數組中，當你嘗試使用Gson解析json時可能導致堆棧溢出錯誤。

“elementos”：“[{.....]”

請使用json驗證器站點為jsonlint驗證json

所以首先我們需要有效的json，我已經通過省略“ json vaild ”

它會是這樣的

改變之后你的Json

{
"atributos": {
    "id": "1",
    "nombre": "Cliente",
    "descripcion": "Cliente",
    "version": "1"
},
"elementos": [
    {
        "id": "1",
        "name": "akira"
    },
    {
        "id": "4",
        "name": "akira"
    },
    {
        "id": "5",
        "name": "akira"
    },
    {
        "id": "6",
        "name": "akira"
    },
    {
        "id": "7",
        "name": "akira"
    },
    {
        "id": "8",
        "name": "akira"
    },
    {
        "id": "9",
        "name": "akira"
    },
    {
        "id": "10",
        "name": "akira"
    },
    {
        "id": "11",
        "name": "akira"
    },
    {
        "id": "12",
        "name": "akira"
    },
    {
        "id": "13",
        "name": "akira"
    },
    {
        "id": "14",
        "name": "akira"
    },
    {
        "id": "15",
        "name": "akira"
    },
    {
        "id": "16",
        "name": "akira"
    },
    {
        "id": "17",
        "name": "akira"
    },
    {
        "id": "18",
        "name": "akira"
    }
]
}

**現在編碼部分：**要使用Gson解析此jsonresponse，請按照以下步驟操作

創建一個類JsonResponse

public class JsonResponse {

 /*Class handle the Whole json*/

//Variable name should be same as the names given in the json response  

Atributos atributos;// Attributos class handles the data in atributos obj from the json . The variable name of Attributos should be same as the json objects ie atributos

ArrayList<ElementosObj>elementos=null;//elementos is a array which hold some datas  ,so make a class ElementosObj to handle the data in the  elementos array.


}

Atributos類

public class Atributos {

 /*Class handle the atributos obj from json*/

  //Variable name should be same as the names given in the json response
public String id = null;
public String nombre = null;
public String descripcion = null;
public String version = null;
}

類ElementosObj

public class ElementosObj {

/*Class handle the elementos array from json*/

//Variable name should be same as the names given in the json response

String id=null;
String name=null;

}

而現在在你的主要課程中你解析了上面的json

主要課程

String jsonData = "String jsonData Contain your parsed jsondata ";


    Gson mGson = new Gson();
    JsonResponse mObj1 = (JsonResponse) mGson.fromJson(jsonData,
            JsonResponse.class);

    Log.d("Atributos:ID", mObj1.atributos.id);
    Log.d("Atributos:DESCRIBTION", mObj1.atributos.descripcion);
    Log.d("Atributos:NUMBER", mObj1.atributos.nombre);
    Log.d("Atributos:VERSION", mObj1.atributos.version);

    for (int i = 0; i < mObj1.elementos.size(); i++) {
        Log.d("Elementos:ID For Postion " + i, mObj1.elementos.get(i).id);
        Log.d("Elementos:NAME For Postion " + i,
                mObj1.elementos.get(i).name);
    }

輸出將是這樣的

05-03 01:32:51.548: D/Atributos:ID: 1
05-03 01:32:51.548: D/Atributos:DESCRIBTION: Cliente
05-03 01:32:51.548: D/Atributos:NUMBER: Cliente
05-03 01:32:51.548: D/Atributos:VERSION: 1
05-03 01:32:51.548: D/Elementos:ID For Postion 0: 1
05-03 01:32:51.548: D/Elementos:NAME For Postion 0: akira
05-03 01:32:51.548: D/Elementos:ID For Postion 1: 4
05-03 01:32:51.558: D/Elementos:NAME For Postion 1: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 2: 5
05-03 01:32:51.558: D/Elementos:NAME For Postion 2: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 3: 6
05-03 01:32:51.558: D/Elementos:NAME For Postion 3: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 4: 7
05-03 01:32:51.558: D/Elementos:NAME For Postion 4: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 5: 8
05-03 01:32:51.558: D/Elementos:NAME For Postion 5: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 6: 9
05-03 01:32:51.558: D/Elementos:NAME For Postion 6: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 7: 10
05-03 01:32:51.558: D/Elementos:NAME For Postion 7: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 8: 11
05-03 01:32:51.558: D/Elementos:NAME For Postion 8: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 9: 12
05-03 01:32:51.558: D/Elementos:NAME For Postion 9: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 10: 13
05-03 01:32:51.558: D/Elementos:NAME For Postion 10: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 11: 14
05-03 01:32:51.558: D/Elementos:NAME For Postion 11: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 12: 15
05-03 01:32:51.558: D/Elementos:NAME For Postion 12: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 13: 16
05-03 01:32:51.558: D/Elementos:NAME For Postion 13: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 14: 17
05-03 01:32:51.558: D/Elementos:NAME For Postion 14: akira
05-03 01:32:51.558: D/Elementos:ID For Postion 15: 18
05-03 01:32:51.558: D/Elementos:NAME For Postion 15: akira

希望這會對你有所幫助謝謝你

Answer 2

萬一其他人遇到這個問題，我的問題是我需要更換：

private final Logger LOGGER = Logger.getLogger(this.getClass().getName());

同

private transient Logger LOGGER = Logger.getLogger(this.getClass().getName());

請注意關鍵字“瞬態”。 這將在https://stackoverflow.com/a/5889590/2308858進一步解釋。