Java 创建了一个接口以获取Arraylist，但仍然获取null

在我的应用程序中，我想在其他类中使用异步类中的ArrayList。为此，我创建了一个接口。但当我在其他类中使用该接口时，我得到的ArrayList的大小为0。我在其他类中使用的ArrayList将其提供给自定义适配器，以便在列表中显示。但由于我的ArrayList大小为0，正在显示空白列表

异步类

public class SearchJobAsync extends AsyncTask<String, String, String> implements GetArrayList {
    private String response;
    Context c;
    SearchModel data;
    ArrayList<SearchModel> values;
    GetArrayList getArrayList;

    public SearchJobAsync(Context c, GetArrayList getArrayList) {
        this.c = c;
        this.getArrayList = getArrayList;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute ();
        CommonFunctions.showProgress (c, "Please Wait...", true);

    }

    @Override
    protected void onPostExecute(String s) {
        values = new ArrayList<SearchModel> ();

        super.onPostExecute (s);
        if (!s.trim ().contains ("Table")) {
            Crouton.makeText ((android.app.Activity) c, "Nothing found", Style.INFO).show ();
        } else {
            try {

                JSONObject jsonObject = new JSONObject (s);
                JSONObject NewDataSet = jsonObject.getJSONObject ("NewDataSet");
                if (NewDataSet.get ("Table") instanceof JSONObject) {
                    JSONObject table = NewDataSet.getJSONObject ("Table");
                    data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                    values.add (data);
                    if(values.size()>0){
                        getArrayList.getList(values);
                    }
                } else if (NewDataSet.get ("Table") instanceof JSONArray) {
                    JSONArray tableArray = NewDataSet.getJSONArray ("Table");

                    for (int i = 0; i < tableArray.length (); i++) {
                        JSONObject table = tableArray.getJSONObject (i);
                        data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                        values.add (data);
                        if(values.size()>0){
                            getArrayList.getList(values);
                        }

                    }

                }



            } catch (JSONException e) {
                e.printStackTrace ();
            }
        }


        CommonFunctions.showProgress (c, "", false);
        Intent i = new Intent (c, SearchJobListActivity.class);
        c.startActivity (i);
    }

    @Override
    protected String doInBackground(String... s) {
        response = HttpRequest.post ("https://beta135.hamarisuraksha.com/web/WebService/HsJobService.asmx/FindJobForVendor").send ("Vendor_IEntity_Code=" + "34588A34-E969-4723-84FE-E5409B66A5B7" + "&Job_Code=" + "&Job_Category=1" + "&Exp_Years_From=0" + "&Exp_Months_From=0" + "&Exp_Years_To=0" + "&Exp_Months_To=0").body ();
        response = response.replaceAll ("<[^>]*>", "").replaceAll ("\n", "");
        Log.e ("Search Jobs", "" + response);
        return response;
    }


    @Override
    public void getList(ArrayList<SearchModel> data) {
       values=data;
    }
}

公共类SearchJobAsync扩展AsyncTask实现GetArrayList{
私有字符串响应；
上下文c；
搜索模型数据；
数组列表值；
GetArrayList GetArrayList；
public SearchJobAsync（上下文c，GetArrayList GetArrayList）{
这个.c=c；
this.getArrayList=getArrayList；
}
@凌驾
受保护的void onPreExecute（）{
super.onPreExecute（）；
CommonFunctions.showProgress（c，“请稍候…”，true）；
}
@凌驾
受保护的void onPostExecute（字符串s）{
values=newarraylist（）；
super.onPostExecute（s）；
如果（！s.trim（）.包含（“表”））{
Crouton.makeText（（android.app.Activity）c，“找不到任何东西”，Style.INFO.show（）；
}否则{
试一试{
JSONObject JSONObject=新的JSONObject；
JSONObject NewDataSet=JSONObject.getJSONObject（“NewDataSet”）；
if（NewDataSet.get（“表”）JSONObject实例）{
JSONObject table=NewDataSet.getJSONObject（“table”）；
数据=新的搜索模型（table.getString（“工作类别”）、table.getString（“最低经验”）、table.getString（“最高经验”）、table.getString（“发布日期”）、table.getString（“候选人计数”）、table.getString（“应用程序”）、table.getString（“职位编号”）、table.getString（“工作描述”）、table.getString（“工作类型”）、table.getString（“工作小时数”），table.getString（“工作状态”）、table.getString（“工作日期”）、table.getString（“地址”）、table.getString（“性别名称”）、table.getString（“宗教名称”）、table.getString（“经验总结”）、table.getString（“IJob_请求ID”）、table.getString（“请求者名称”）；
values.add（数据）；
如果（values.size（）>0）{
getArrayList.getList（值）；
}
}else if（NewDataSet.get（“Table”）JSONArray实例）{
JSONArray tableArray=NewDataSet.getJSONArray（“表格”）；
for（inti=0；i0）{
getArrayList.getList（值）；
}
}
}
}捕获（JSONException e）{
e、 printStackTrace（）；
}
}
CommonFunctions.showProgress（c，“，false）；
意向i=新意向（c，SearchJobListActivity.class）；
c、 星触觉（i）；
}
@凌驾
受保护的字符串背景（字符串…s）{
响应=HttpRequest.post（“https://beta135.hamarisuraksha.com/web/WebService/HsJobService.asmx/FindJobForVendor发送（“供应商业务代码=“+”34588A34-E969-4723-84FE-E5409B66A5B7“+”&作业代码=“+”&作业类别=1“+”&经验年从=0“+”&经验月从=0“+”&经验年到=0“+”&经验月到=0”）。正文（）；
response=response.replaceAll（“]*>”，“”）。replaceAll（“\n”，“”）；
Log.e（“搜索作业”，“响应”）；
返回响应；
}
@凌驾
公共void getList（ArrayList数据）{
数值=数据；
}
}

接口

public interface GetArrayList  {

public void getList(ArrayList<SearchModel> data);
}

公共接口GetArrayList{
公共void getList（ArrayList数据）；
}

类中使用ArrayList的位置

public class SearchJobList extends ListFragment implements GetArrayList {
    private View view;
    private ListView lvSearchJobs;
    private ArrayList<SearchModel> value;
    SearchJobCustomList customList;
    SearchJobAsync searchJobAsync;
    private Context c;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate (R.layout.search_job_lists, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated (savedInstanceState);
        c = getActivity ();
        lvSearchJobs = (ListView) getActivity ().findViewById (android.R.id.list);
        value = new ArrayList<SearchModel> ();
        searchJobAsync = new SearchJobAsync (c,this);
        customList = new SearchJobCustomList (c, value);
        setListAdapter (customList);
//        searchJobAsync.execute ();


    }

    @Override
    public void getList(ArrayList<SearchModel> data) {
        value=data;

    }
}

公共类SearchJobList扩展ListFragment实现GetArrayList{
私人视野；
私有ListView lvSearchJobs；
私有数组列表值；
SearchJobCustomList自定义列表；
SearchJobAsync SearchJobAsync；
私有上下文c；
@凌驾
CreateView上的公共视图（布局、充气机、视图组容器、捆绑包保存状态）{
视图=充气机。充气（R.layout.search\u job\u list，container，false）；
返回视图；
}
@凌驾
已创建ActivityState上的公共无效（Bundle savedInstanceState）{
super.onActivityCreated（savedInstanceState）；
c=getActivity（）；
lvSearchJobs=（ListView）getActivity（）.findviewbyd（android.R.id.list）；
value=newarraylist（）；
searchJobAsync=新的searchJobAsync（c，this）；
customList=新的SearchJobCustomList（c，值）；
setListAdapter（自定义列表）；
//searchJobAsync.execute（）；
}
@凌驾
公共void getList（ArrayList数据）{
值=数据；
}
}

您可能应该这样定义界面：

public interface GetArrayList  {    
  List<SearchModel> getList();
}

@Override
public List<SearchModel> getList() {
    return Collections.unmodifiableList(value);
}

---

最后注意：

GetArrayList

对于接口来说是一个奇怪的名称。通常，接口应该以描述性的方式命名，而不是直接以它们所持有的方法命名。例如，您可以调用界面

列表持有者

或

搜索模型目录

尝试这种方式，希望这将帮助您解决问题。

public class SearchJobList extends ListFragment {
    private View view;
    private ListView lvSearchJobs;
    private ArrayList<SearchModel> value;
    SearchJobCustomList customList;
    SearchJobAsync searchJobAsync;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate (R.layout.search_job_lists, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated (savedInstanceState);
        lvSearchJobs = (ListView) getActivity ().findViewById (android.R.id.list);
        new SearchJobAsync(getActivity(),new GetArrayList() {
            @Override
            public void getList(ArrayList<SearchModel> data) {
                value = data;
                customList = new SearchJobCustomList (c, value);
                setListAdapter (customList);
            }
        }).execute();
    }

}

public class SearchJobAsync extends AsyncTask<String, String, String> {
    private Context c;
    private String response;
    SearchModel data;
    ArrayList<SearchModel> values;
    GetArrayList getArrayList;

    public SearchJobAsync(Context c, GetArrayList getArrayList) {
        this.c = c;
        this.getArrayList = getArrayList;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute ();
        CommonFunctions.showProgress (c, "Please Wait...", true);

    }

    @Override
    protected void onPostExecute(String s) {
        values = new ArrayList<SearchModel> ();

        super.onPostExecute (s);
        if (!s.trim ().contains ("Table")) {
            Crouton.makeText ((android.app.Activity) c, "Nothing found", Style.INFO).show ();
        } else {
            try {

                JSONObject jsonObject = new JSONObject (s);
                JSONObject NewDataSet = jsonObject.getJSONObject ("NewDataSet");
                if (NewDataSet.get ("Table") instanceof JSONObject) {
                    JSONObject table = NewDataSet.getJSONObject ("Table");
                    data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                    values.add (data);
                } else if (NewDataSet.get ("Table") instanceof JSONArray) {
                    JSONArray tableArray = NewDataSet.getJSONArray ("Table");

                    for (int i = 0; i < tableArray.length (); i++) {
                        JSONObject table = tableArray.getJSONObject (i);
                        data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                        values.add (data);
                    }
                }

            } catch (JSONException e) {
                e.printStackTrace ();
            }
            CommonFunctions.showProgress (c, "Please Wait...",false);
            getArrayList.getList(values);
        }
    }

    @Override
    protected String doInBackground(String... s) {
        response = HttpRequest.post ("https://beta135.hamarisuraksha.com/web/WebService/HsJobService.asmx/FindJobForVendor").send ("Vendor_IEntity_Code=" + "34588A34-E969-4723-84FE-E5409B66A5B7" + "&Job_Code=" + "&Job_Category=1" + "&Exp_Years_From=0" + "&Exp_Months_From=0" + "&Exp_Years_To=0" + "&Exp_Months_To=0").body ();
        response = response.replaceAll ("<[^>]*>", "").replaceAll ("\n", "");
        Log.e ("Search Jobs", "" + response);
        return response;
    }

}

公共类SearchJobList扩展了ListF
public class SearchJobList extends ListFragment {
    private View view;
    private ListView lvSearchJobs;
    private ArrayList<SearchModel> value;
    SearchJobCustomList customList;
    SearchJobAsync searchJobAsync;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate (R.layout.search_job_lists, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated (savedInstanceState);
        lvSearchJobs = (ListView) getActivity ().findViewById (android.R.id.list);
        new SearchJobAsync(getActivity(),new GetArrayList() {
            @Override
            public void getList(ArrayList<SearchModel> data) {
                value = data;
                customList = new SearchJobCustomList (c, value);
                setListAdapter (customList);
            }
        }).execute();
    }

}

public class SearchJobAsync extends AsyncTask<String, String, String> {
    private Context c;
    private String response;
    SearchModel data;
    ArrayList<SearchModel> values;
    GetArrayList getArrayList;

    public SearchJobAsync(Context c, GetArrayList getArrayList) {
        this.c = c;
        this.getArrayList = getArrayList;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute ();
        CommonFunctions.showProgress (c, "Please Wait...", true);

    }

    @Override
    protected void onPostExecute(String s) {
        values = new ArrayList<SearchModel> ();

        super.onPostExecute (s);
        if (!s.trim ().contains ("Table")) {
            Crouton.makeText ((android.app.Activity) c, "Nothing found", Style.INFO).show ();
        } else {
            try {

                JSONObject jsonObject = new JSONObject (s);
                JSONObject NewDataSet = jsonObject.getJSONObject ("NewDataSet");
                if (NewDataSet.get ("Table") instanceof JSONObject) {
                    JSONObject table = NewDataSet.getJSONObject ("Table");
                    data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                    values.add (data);
                } else if (NewDataSet.get ("Table") instanceof JSONArray) {
                    JSONArray tableArray = NewDataSet.getJSONArray ("Table");

                    for (int i = 0; i < tableArray.length (); i++) {
                        JSONObject table = tableArray.getJSONObject (i);
                        data = new SearchModel (table.getString ("Job_Category"), table.getString ("Min_Exp"), table.getString ("Max_Exp"), table.getString ("Posted_On"), table.getString ("Candidate_Counts"), table.getString ("Applications"), table.getString ("No_Of_Pos"), table.getString ("Job_Desc"), table.getString ("Job_Type"), table.getString ("Job_Hours"), table.getString ("Job_Status"), table.getString ("Job_Exp_Date"), table.getString ("Address"), table.getString ("Gender_Name"), table.getString ("Religion_Name"), table.getString ("Exp_Summary"), table.getString ("IJob_Request_ID"), table.getString ("Requestor_Name"));
                        values.add (data);
                    }
                }

            } catch (JSONException e) {
                e.printStackTrace ();
            }
            CommonFunctions.showProgress (c, "Please Wait...",false);
            getArrayList.getList(values);
        }
    }

    @Override
    protected String doInBackground(String... s) {
        response = HttpRequest.post ("https://beta135.hamarisuraksha.com/web/WebService/HsJobService.asmx/FindJobForVendor").send ("Vendor_IEntity_Code=" + "34588A34-E969-4723-84FE-E5409B66A5B7" + "&Job_Code=" + "&Job_Category=1" + "&Exp_Years_From=0" + "&Exp_Months_From=0" + "&Exp_Years_To=0" + "&Exp_Months_To=0").body ();
        response = response.replaceAll ("<[^>]*>", "").replaceAll ("\n", "");
        Log.e ("Search Jobs", "" + response);
        return response;
    }

}