Android解析对Java ArrayList的Json响应

我试图通过截击向我的WCF服务发出GET请求，我想解析它对Java

ArrayList

的响应。这是我的方法

    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;
}

---

我能够得到JSON响应，但

ArrayList

返回空值。我认为，

onResponse

是一个calback方法，在另一个线程中运行，因此我无法填充列表，但由于我是Android新手，我不知道如何处理这个问题。任何帮助都将不胜感激。

JsonObjectRequest

工作异步，因为主线程将继续运行，并创建一个新线程来运行JsonObjectRequest，结果是返回值为空。在类中调用一个方法以发回数据，并在完成json数据管理后调用它，例如：

public void manageCompaniesData(ArrayList<Company>){

    //YOUR CODE HERE.

}

public void管理公司数据（ArrayList）{
//你的代码在这里。
}

您的代码已修改：

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);

    }

public ArrayList getcompanys（）{
字符串url=AUDITTRACKINGAPP\u服务\u URI+“GetCompanys”；
字符串tagJsonReq=“companiesRequest”；
final ProgressDialog pDialog=新建ProgressDialog（上下文）；
setMessage（“请稍候…”）；
pDialog.show（）；
最终ArrayList公司=新ArrayList（）；
JsonObjectRequest CompanyRequest=新的JsonObjectRequest（Request.Method.GET，url，null，
新的Response.Listener（）{
@凌驾
公共void onResponse（JSONObject响应）{
Log.v（标记“companys RESPONSE:+RESPONSE.toString（））；
试一试{
JSONArray companiesJson=response.getJSONArray（“GetCompaniesResult”）；
for（int i=0；i

JsonObjectRequest

工作异步，因为主线程继续运行，并且创建了一个新线程来运行JsonObjectRequest，结果是返回值为空。在类中调用一个方法以发回数据，并在完成json数据管理后调用它，例如：

public void manageCompaniesData(ArrayList<Company>){

    //YOUR CODE HERE.

}

public void管理公司数据（ArrayList）{
//你的代码在这里。
}

您的代码已修改：

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);

    }

public ArrayList getcompanys（）{
字符串url=AUDITTRACKINGAPP\u服务\u URI+“GetCompanys”；
字符串tagJsonReq=“companiesRequest”；
final ProgressDialog pDialog=新建ProgressDialog（上下文）；
setMessage（“请稍候…”）；
pDialog.show（）；
最终ArrayList公司=新ArrayList（）；
JsonObjectRequest CompanyRequest=新的JsonObjectRequest（Request.Method.GET，url，null，
新的Response.Listener（）{
@凌驾
公共void onResponse（JSONObject响应）{
Log.v（标记“companys RESPONSE:+RESPONSE.toString（））；
试一试{
JSONArray companiesJson=response.getJSONArray（“GetCompaniesResult”）；
for（int i=0；i

如果在logcat中出现任何JSON异常，请尝试一次

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);
 }

for（int i=0；iJSONObject jObject = (JSONObject)companiesJson.get(i);

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);
 }

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);
 }

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());
                        }

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

                        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);