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Android Parse Json響應Java ArrayList

2016-04-07 92 views
1

我想通過Volley向我的WCF服務發出GET請求，我想解析它對Java ArrayList的響應。這裏是我的方法Android Parse Json響應Java ArrayList

public ArrayList<Company> getCompanies(){ 

     String url = AUDITTRACKINGAPP_SERVICE_URI + "GetCompanies"; 
     String tagJsonReq = "companiesRequest"; 

     final ProgressDialog pDialog = new ProgressDialog(context); 
     pDialog.setMessage("Please Wait..."); 
     pDialog.show(); 

     final ArrayList<Company> companies = new ArrayList<Company>(); 

     JsonObjectRequest companiesRequest = new JsonObjectRequest( Request.Method.GET, url, null, 
       new Response.Listener<JSONObject>() { 
        @Override 
        public void onResponse(JSONObject response) { 

         Log.v(TAG, "COMPANIES RESPONSE:" + response.toString()); 

         try { 
          JSONArray companiesJson = response.getJSONArray("GetCompaniesResult"); 

          for (int i = 0; i < companiesJson.length(); i++) { 

           JSONObject jObject = (JSONObject)companiesJson.get(i); 

           Company company = new Company(); 
           company.setCompanyId(Integer.parseInt(jObject.getString("CompanyId"))); 
           Log.v(TAG, "COMPANIES setCompanyId:" + jObject.getString("CompanyId")); 
           company.setCompanyName(jObject.getString("CompanyName")); 
           Log.v(TAG, "COMPANIES setCompanyName:" + jObject.getString("CompanyName")); 

           companies.add(company); 
          } 

         } catch (JSONException e) { 
          Log.v(TAG, "COMPANIES RESPONSE ERROR ON PARSING JSON:" + e.getMessage()); 
         } 

         pDialog.hide(); 
        } 
       }, 
       new Response.ErrorListener() { 

       @Override 
       public void onErrorResponse(VolleyError error) { 
        Log.v(TAG, "COMPANIES onErrorResponse:" + error.getMessage()); 
        pDialog.hide(); 
       } 
      }); 

    AppController.getInstance().addToRequestQueue(companiesRequest, tagJsonReq); 

    return companies; 
}

JSON響應：

{"GetCompaniesResult":[{"CompanyId":1,"CompanyName":"CompanyName1"},{"CompanyId":2,"CompanyName":"CompanyName2"}]}

我能夠得到JSON響應，但ArrayList<Company>返回null。我認爲onResponse是一個回調方法，並在另一個線程運行，所以我不能填充列表，但因爲我是Android新手我不知道如何管理這個問題。任何幫助，將不勝感激。

來源

2016-04-07 Tartar

+1

你會得到輸出日誌？ –

+0

是的，我看到JSON響應@AiyazParmar – Tartar

+0

是你的for循環執行成功嗎？ –

回答

0

JsonObjectRequest工程異步因爲主線程繼續運行，並且創建一個新的線程來運行JsonObjectRequest，結果是您的返回值爲null。在類中調用一個方法將數據發回，並調用它，當你完成管理JSON數據，例如：

public void manageCompaniesData(ArrayList<Company>){ 

    //YOUR CODE HERE. 

}

您的代碼修改：

public ArrayList<Company> getCompanies(){ 

String url = AUDITTRACKINGAPP_SERVICE_URI + "GetCompanies"; 
     String tagJsonReq = "companiesRequest"; 

     final ProgressDialog pDialog = new ProgressDialog(context); 
     pDialog.setMessage("Please Wait..."); 
     pDialog.show(); 

     final ArrayList<Company> companies = new ArrayList<Company>(); 

     JsonObjectRequest companiesRequest = new JsonObjectRequest( Request.Method.GET, url, null, 
       new Response.Listener<JSONObject>() { 
        @Override 
        public void onResponse(JSONObject response) { 

         Log.v(TAG, "COMPANIES RESPONSE:" + response.toString()); 

         try { 
          JSONArray companiesJson = response.getJSONArray("GetCompaniesResult"); 

          for (int i = 0; i < companiesJson.length(); i++) { 

           JSONObject jObject = (JSONObject)companiesJson.get(i); 

           Company company = new Company(); 
           company.setCompanyId(Integer.parseInt(jObject.getString("CompanyId"))); 
           Log.v(TAG, "COMPANIES setCompanyId:" + jObject.getString("CompanyId")); 
           company.setCompanyName(jObject.getString("CompanyName")); 
           Log.v(TAG, "COMPANIES setCompanyName:" + jObject.getString("CompanyName")); 

           companies.add(company); 
          } 

         } catch (JSONException e) { 
          Log.v(TAG, "COMPANIES RESPONSE ERROR ON PARSING JSON:" + e.getMessage()); 
         } 
         manageCompaniesData(companies); 
         pDialog.hide(); 
        } 
       }, 
       new Response.ErrorListener() { 

       @Override 
       public void onErrorResponse(VolleyError error) { 
        Log.v(TAG, "COMPANIES onErrorResponse:" + error.getMessage()); 
        pDialog.hide(); 
       } 
      }); 

    AppController.getInstance().addToRequestQueue(companiesRequest, tagJsonReq); 

    }

來源

2016-04-07 12:40:11

+0

這就是爲什麼他會傳遞一個迴應。監聽器的調用，爲了管理異步響應 –

+0

但是這個監聽器是在其他線程 –

+0

onResponse（）總是在UI線程上運行 –

-1

，如果你在任何JSON異常logcat，試試這個。

for (int i = 0; i < companiesJson.length(); i++) { 

          JSONObject jObject = companiesJson.getJSONObject(i); 
          Company company = new Company(); 
          company.setCompanyId(Integer.parseInt(jObject.getString("CompanyId"))); 
          Log.v(TAG, "COMPANIES setCompanyId:" + jObject.getString("CompanyId")); 
          company.setCompanyName(jObject.getString("CompanyName")); 
          Log.v(TAG, "COMPANIES setCompanyName:" + jObject.getString("CompanyName")); 
          companies.add(company); 
}

來源

2016-04-07 13:02:34

+0

你甚至讀過這個問題嗎？ – Tartar

+0

你會得到「Log.v（TAG，」COMPANIES setCompanyId：「+ jObject.getString（」CompanyId「））;」在logcat。 –

+0

是的，請閱讀這個問題。 – Tartar

0

JSONArray對象有一個函數getJSONObject(int index)所以你必須使用

JSONObject jObject = companiesJson.getJSONObject(i);

代替

JSONObject jObject = (JSONObject)companiesJson.get(i);

試試這個代碼。

for (int i = 0; i < companiesJson.length(); i++) { 
    JSONObject jObject = companiesJson.getJSONObject(i); 
    Company company = new Company(); 
    company.setCompanyId(jObject.getInt("CompanyId"))); 
    company.setCompanyName(jObject.getString("CompanyName")); 
    companies.add(company); 
}

代替

for (int i = 0; i < companiesJson.length(); i++) { 
    JSONObject jObject = (JSONObject)companiesJson.get(i); 
    Company company = new Company(); 
    company.setCompanyId(Integer.parseInt(jObject.getString("CompanyId"))); 
    Log.v(TAG, "COMPANIES setCompanyId:" + jObject.getString("CompanyId")); 
    company.setCompanyName(jObject.getString("CompanyName")); 
    Log.v(TAG, "COMPANIES setCompanyName:" + jObject.getString("CompanyName")); 

    companies.add(company); 
}

來源

2016-04-07 13:04:33 Rajesh

5

您需要創建JSON數組中的每個元素

try { 
          JSONArray companiesJson = response.getJSONArray("GetCompaniesResult"); 

          for (int i = 0; i < companiesJson.length(); i++) { 


        JSONObject obj = Website.getJSONObject(i); 


           Company company = new Company(); 
           company.setCompanyId(Integer.parseInt(obj.getString("CompanyId"))); 
           Log.v(TAG, "COMPANIES setCompanyId:" + obj.getString("CompanyId")); 
           company.setCompanyName(obj.getString("CompanyName")); 
           Log.v(TAG, "COMPANIES setCompanyName:" + obj.getString("CompanyName")); 

           companies.add(company); 
          } 

         } catch (JSONException e) { 
          Log.v(TAG, "COMPANIES RESPONSE ERROR ON PARSING JSON:" + e.getMessage()); 
         }

來源

2016-04-07 13:13:11

+0

他已經這樣做了：JSONObject jObject =（JSONObject）companiesJson.get（i）; –

0

解析您的JSON這樣的for內的JSON對象loop.Also不要聲明ArrayList公司爲final。

Company company = new Company(); 
JSONObject jObject = (JSONObject)companiesJson.optJSONObject(i); 
if(jObject != null){ 
    company.setCompanyId(jObject.optInt("CompanyId"))); 
    company.setCompanyName(jObject.optString("CompanyName")); 
}

來源

2016-04-07 13:21:54

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