Android 无法在listview中获取json数据

这是主要活动，我有asynktask，jsonparsor文件。。我想获取json dat，其格式如下：

{
    "status": 1,
    "records": [
        {
            "member_id": "10",
            "member_name": "RavinderKaur",
            "gender": "1",
            "dob": "15-7-2014",
            "email": "rv@gmail.com",
            "contact_no": "1234567891",
            "address": "",
            "member_password": "25d55ad283aa400af464c76d713c07ad",
            "member_designation": "",
            "created_date": "2014-05-18 22:49:34"
        }
    ]
}

代码：

这是我的AsynckTask文件：

package com.example.capo.net;

import org.json.JSONObject;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;

public class JSONGetRequest extends AsyncTask<String, Void, JSONObject> {

private static Context mContext;
private static JSONGetRequest singleInstance;
private ProgressDialog mDialog;


public static JSONGetRequest getSingleInstance(Context context) {

    singleInstance = new JSONGetRequest();

    mContext = context;

    return singleInstance;
}

@Override
protected void onPreExecute() {
    // TODO Auto-generated method stub
    super.onPreExecute();

    mDialog = new ProgressDialog(mContext);
    mDialog.setMessage("Please wait");
    mDialog.show();

}

@Override
protected JSONObject doInBackground(String... params) {

    try {
        // Creating JSON Parser instance
        JSONParser jParser = new JSONParser();

        // getting JSON string from URL
        JSONObject json = jParser.getJSONFromUrl(params[0]);

        return json;

    } catch (Exception e) {

        System.out.println(e);
    }

    return null;

}

@Override
public void onPostExecute(JSONObject result) {
    // TODO Auto-generated method stub
    super.onPostExecute(result);

    mDialog.dismiss();
}
}

这是我的注册文件，我可以从中正确存储数据：

package com.example.capo.ui;

import java.util.concurrent.ExecutionException;

import org.json.JSONException;
import org.json.JSONObject;

import com.example.capo.R;
import com.example.capo.net.JSONGetRequest;
import com.example.capo.services.NotificationServices;
import com.example.capo.services.Tags;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.PopupWindow;
import android.widget.RadioButton;
import android.widget.Toast;

public class RformActivity extends Activity implements OnDateSetListener,
    OnClickListener {

// declaration of variables

private EditText mFirstName, mLastName, mEmail, mDob, mMobile,
        mPassword, mConfirmPassword, mdesignation;
private RadioButton mMale, mFemale;
private ImageView mSubmit;

public static String number, password;

private String gender;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_rform);

    // reference from their Ids

    mFirstName = (EditText) findViewById(R.id.etFirstName);
    mLastName = (EditText) findViewById(R.id.etLastName);
    mEmail = (EditText) findViewById(R.id.etEmail);
    mDob = (EditText) findViewById(R.id.etDob);
    mMobile = (EditText) findViewById(R.id.etMobile);

    mPassword = (EditText) findViewById(R.id.etPassword);
    mConfirmPassword = (EditText) findViewById(R.id.etConfirmPassword);
    mdesignation = (EditText) findViewById(R.id.etDesignation);
    mMale = (RadioButton) findViewById(R.id.rbMale);
    mFemale = (RadioButton) findViewById(R.id.rbFemale);
    mSubmit = (ImageView) findViewById(R.id.btnSubmit);

    mDob.setOnClickListener(this);
    mSubmit.setOnClickListener(this);

    if(mMale.isChecked()){gender = "0";}else{ gender = "1"; }


}

// to show the date in given pattern
@Override
public void onDateSet(DatePicker arg0, int year, int month, int day) {

    String s = day + "-" + month + "-" + year;
    mDob.setText(s);

}

@Override
public void onClick(View arg0) {

    if (arg0 == mDob) {

        DatePickerDialog dt = new DatePickerDialog(RformActivity.this,
                (OnDateSetListener) RformActivity.this, 2014, 07, 15);
        dt.show();

    }

    if (arg0 == mSubmit) {

        String firstname = mFirstName.getText().toString();
        String lastname = mLastName.getText().toString();
        String email = mEmail.getText().toString();
        String dob = mDob.getText().toString();
        number = mMobile.getText().toString();
        password = mPassword.getText().toString();
        String confirmpassword = mConfirmPassword.getText().toString();
        String designation = mdesignation.getText().toString(); 

        if (firstname.equals("") || lastname.equals("") || email.equals("") || dob.equals("")
                || number.equals("") 
                || designation.equals("") || password.equals("")
                || confirmpassword.equals("")) {

            NotificationServices.showToast(getApplicationContext(),
                    "Fill the empty fields");

        }else if (isEmail(email)){

        if (number.length() < 10 || number.length() == 11) {

            NotificationServices.showToast(getApplicationContext(),
                    "Enter correct number");

        }else if (password.length() < 8) {

            NotificationServices.showToast(getApplicationContext(),
                    "Password should not be less than Eight");

        }else if (password.equals(confirmpassword)) {

            NotificationServices.showToast(getApplicationContext(),
                    "Checking for Sign Up");

            JSONGetRequest jRequest = JSONGetRequest
                    .getSingleInstance(RformActivity.this);

            try {

                String url = (Tags.url + "request=registration&name="
                        + (firstname+lastname) + "&gender=" + gender +"&email=" + email + "&mobile=" + number
                        + "&dob=" + dob + "&password=" + password + "&designation" + designation).replaceAll(" ", "%20");

                JSONObject result = jRequest.execute(url).get();

                if (result.getString("status").equals("1")) {

                    Intent intent = new Intent(RformActivity.this,
                            HomeTabActivity.class);

                    startActivity(intent);

                } else {

                    Toast.makeText(getApplicationContext(),
                                result.getString("message"), Toast.LENGTH_SHORT)
                            .show();

                }

            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ExecutionException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }



        } else {

            NotificationServices.showToast(getApplicationContext(),
                    "Password not matches");

        }
    }
}
}

private boolean isEmail(String email) {

    if (email.contains("@")
            && email.contains(".")
            && email.indexOf("@") == email.lastIndexOf("@")
            && email.indexOf("@") != (email.indexOf(".") + 1)
            && (email.indexOf("@") + 1) != email.indexOf(".")
            && (!email.contains("^")) && (!email.contains(" "))
            && (!email.contains("-")) && (!email.contains("--"))) {

        return true;

    } else {

        NotificationServices.showToast(getApplicationContext(),
                "Enter correct Email.");
        return false;
    }

}

}

package com.example.capo.ui；
导入java.util.concurrent.ExecutionException；
导入org.json.JSONException；
导入org.json.JSONObject；
导入com.example.capo.R；
导入com.example.capo.net.JSONGetRequest；
导入com.example.capo.services.NotificationServices；
导入com.example.capo.services.Tags；
导入android.app.Activity；
导入android.app.DatePickerDialog；
导入android.app.DatePickerDialog.OnDateSetListener；
导入android.content.Context；
导入android.content.Intent；
导入android.database.sqlite.SQLiteDatabase；
导入android.os.Bundle；
导入android.view.Gravity；
导入android.view.LayoutInflater；
导入android.view.Menu；
导入android.view.MenuInflater；
导入android.view.MenuItem；
导入android.view.view；
导入android.view.ViewGroup；
导入android.view.view.OnClickListener；
导入android.widget.Button；
导入android.widget.DatePicker；
导入android.widget.EditText；
导入android.widget.ImageView；
导入android.widget.PopupWindow；
导入android.widget.RadioButton；
导入android.widget.Toast；
公共类RformActivity扩展活动实现OnDateSetListener，
onclick侦听器{
//变量声明
私有编辑文本mFirstName、mLastName、mEmail、mDob、mMobile、，
mPassword、mConfirmPassword、mdesignation；
私人无线按钮mMale，mFemale；
私有ImageView mSubmit；
公共静态字符串编号、密码；
私人字符串性别；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u rform）；
//从他们的ID引用
mFirstName=（EditText）findViewById（R.id.etFirstName）；
mLastName=（EditText）findViewById（R.id.etLastName）；
mEmail=（EditText）findViewById（R.id.etEmail）；
mDob=（EditText）findViewById（R.id.etDob）；
mMobile=（EditText）findViewById（R.id.etMobile）；
mPassword=（EditText）findViewById（R.id.etPassword）；
mConfirmPassword=（EditText）findViewById（R.id.etConfirmPassword）；
mdesignation=（EditText）findViewById（R.id.etDesignation）；
mMale=（单选按钮）findViewById（R.id.rbMale）；
mFemale=（单选按钮）findViewById（R.id.rbFemale）；
mSubmit=（ImageView）findViewById（R.id.btnSubmit）；
mDob.setOnClickListener（这个）；
mSubmit.setOnClickListener（这个）；
if（mMale.isChecked（））{gender=“0”}else{gender=“1”}
}
//以给定的模式显示日期
@凌驾
公共无效onDateSet（日期选择器arg0，整数年，整数月，整数天）{
字符串s=日+“-”+月+“-”+年；
mDob.setText（s）；
}
@凌驾
公共void onClick（视图arg0）{
如果（arg0==mDob）{
DatePickerDialog dt=新的DatePickerDialog（RformActivity.this，
（OnDateSetListener）RformActivity.this，2014,07,15）；
dt.show（）；
}
如果（arg0==mSubmit）{
String firstname=mFirstName.getText（）.toString（）；
字符串lastname=mLastName.getText（）.toString（）；
字符串email=mEmail.getText（）.toString（）；
字符串dob=mDob.getText（）.toString（）；
number=mMobile.getText（）.toString（）；
password=mPassword.getText（）.toString（）；
字符串confirmpassword=mConfirmPassword.getText（）.toString（）；
字符串名称=mdesignation.getText（）.toString（）；
如果（firstname.equals（“”）| lastname.equals（“”）| email.equals（“”）| dob.equals（“”）
||数字。等于（“”）
||名称.equals（“”）|密码.equals（“”）
||confirmpassword.equals（“”）{
NotificationServices.showToast（getApplicationContext（），
“填写空白字段”）；
}其他如果（电子邮件）{
if（number.length（）<10 | | number.length（）==11）{
NotificationServices.showToast（getApplicationContext（），
“输入正确的数字”）；
}else if（password.length（）<8）{
NotificationServices.showToast（getApplicationContext（），
“密码不得少于8”）；
}else if（password.equals（confirmpassword））{
NotificationServices.showToast（getApplicationContext（），
“检查注册情况”）；
JSONGetRequest jRequest=JSONGetRequest
.getSingleInstance（RformActivity.this）；
试一试{
字符串url=（Tags.url+“请求=注册&名称=”
+（firstname+lastname）+“&gender=“+gender+”&email=“+email+”&mobile=“+number
+&dob=“+dob+”&password=“+password+”&designation”+designation.replaceAll（“，“%20”）；
JSONObject result=jRequest.execute（url.get（）；
if（result.getString（“status”）.equals（“1”））{
意向意向=新意向（RformActivity.this，
家庭活动（课堂）；
星触觉（意向）；
}否则{
Toast.makeText（getApplicationContext（），
result.getString（“消息”），Toast.LENGTH\u SHORT）
.show（）；
}
}捕捉（中断异常e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}捕获（执行例外）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}捕获（JSONException e）{
//TODO自动生成的捕捉块
e、 printStackTrace（）；
}
}否则{
NotificationServices.showToast（getApplicationContext（），
“密码不匹配”）；
package com.example.capo.net;

import org.json.JSONObject;

import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;

public class JSONGetRequest extends AsyncTask<String, Void, JSONObject> {

private static Context mContext;
private static JSONGetRequest singleInstance;
private ProgressDialog mDialog;


public static JSONGetRequest getSingleInstance(Context context) {

    singleInstance = new JSONGetRequest();

    mContext = context;

    return singleInstance;
}

@Override
protected void onPreExecute() {
    // TODO Auto-generated method stub
    super.onPreExecute();

    mDialog = new ProgressDialog(mContext);
    mDialog.setMessage("Please wait");
    mDialog.show();

}

@Override
protected JSONObject doInBackground(String... params) {

    try {
        // Creating JSON Parser instance
        JSONParser jParser = new JSONParser();

        // getting JSON string from URL
        JSONObject json = jParser.getJSONFromUrl(params[0]);

        return json;

    } catch (Exception e) {

        System.out.println(e);
    }

    return null;

}

@Override
public void onPostExecute(JSONObject result) {
    // TODO Auto-generated method stub
    super.onPostExecute(result);

    mDialog.dismiss();
}
}

package com.example.capo.beans;

public class MyProfile {

public String name , email,gender, dob, mobile,
 designation;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getEmail() {
    return email;
}

public void setEmail(String email) {
    this.email = email;
}

public String getGender() {
    return gender;
}

public void setGender(String gender) {
    this.gender = gender;
}

public String getDob() {
    return dob;
}

public void setDob(String dob) {
    this.dob = dob;
}

public String getMobile() {
    return mobile;
}

public void setMobile(String mobile) {
    this.mobile = mobile;
}

public String getDesignation() {
    return designation;
}

public void setDesignation(String designation) {
    this.designation = designation;
}
}

package com.example.capo.ui;

import java.util.concurrent.ExecutionException;

import org.json.JSONException;
import org.json.JSONObject;

import com.example.capo.R;
import com.example.capo.net.JSONGetRequest;
import com.example.capo.services.NotificationServices;
import com.example.capo.services.Tags;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.content.Context;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.PopupWindow;
import android.widget.RadioButton;
import android.widget.Toast;

public class RformActivity extends Activity implements OnDateSetListener,
    OnClickListener {

// declaration of variables

private EditText mFirstName, mLastName, mEmail, mDob, mMobile,
        mPassword, mConfirmPassword, mdesignation;
private RadioButton mMale, mFemale;
private ImageView mSubmit;

public static String number, password;

private String gender;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_rform);

    // reference from their Ids

    mFirstName = (EditText) findViewById(R.id.etFirstName);
    mLastName = (EditText) findViewById(R.id.etLastName);
    mEmail = (EditText) findViewById(R.id.etEmail);
    mDob = (EditText) findViewById(R.id.etDob);
    mMobile = (EditText) findViewById(R.id.etMobile);

    mPassword = (EditText) findViewById(R.id.etPassword);
    mConfirmPassword = (EditText) findViewById(R.id.etConfirmPassword);
    mdesignation = (EditText) findViewById(R.id.etDesignation);
    mMale = (RadioButton) findViewById(R.id.rbMale);
    mFemale = (RadioButton) findViewById(R.id.rbFemale);
    mSubmit = (ImageView) findViewById(R.id.btnSubmit);

    mDob.setOnClickListener(this);
    mSubmit.setOnClickListener(this);

    if(mMale.isChecked()){gender = "0";}else{ gender = "1"; }


}

// to show the date in given pattern
@Override
public void onDateSet(DatePicker arg0, int year, int month, int day) {

    String s = day + "-" + month + "-" + year;
    mDob.setText(s);

}

@Override
public void onClick(View arg0) {

    if (arg0 == mDob) {

        DatePickerDialog dt = new DatePickerDialog(RformActivity.this,
                (OnDateSetListener) RformActivity.this, 2014, 07, 15);
        dt.show();

    }

    if (arg0 == mSubmit) {

        String firstname = mFirstName.getText().toString();
        String lastname = mLastName.getText().toString();
        String email = mEmail.getText().toString();
        String dob = mDob.getText().toString();
        number = mMobile.getText().toString();
        password = mPassword.getText().toString();
        String confirmpassword = mConfirmPassword.getText().toString();
        String designation = mdesignation.getText().toString(); 

        if (firstname.equals("") || lastname.equals("") || email.equals("") || dob.equals("")
                || number.equals("") 
                || designation.equals("") || password.equals("")
                || confirmpassword.equals("")) {

            NotificationServices.showToast(getApplicationContext(),
                    "Fill the empty fields");

        }else if (isEmail(email)){

        if (number.length() < 10 || number.length() == 11) {

            NotificationServices.showToast(getApplicationContext(),
                    "Enter correct number");

        }else if (password.length() < 8) {

            NotificationServices.showToast(getApplicationContext(),
                    "Password should not be less than Eight");

        }else if (password.equals(confirmpassword)) {

            NotificationServices.showToast(getApplicationContext(),
                    "Checking for Sign Up");

            JSONGetRequest jRequest = JSONGetRequest
                    .getSingleInstance(RformActivity.this);

            try {

                String url = (Tags.url + "request=registration&name="
                        + (firstname+lastname) + "&gender=" + gender +"&email=" + email + "&mobile=" + number
                        + "&dob=" + dob + "&password=" + password + "&designation" + designation).replaceAll(" ", "%20");

                JSONObject result = jRequest.execute(url).get();

                if (result.getString("status").equals("1")) {

                    Intent intent = new Intent(RformActivity.this,
                            HomeTabActivity.class);

                    startActivity(intent);

                } else {

                    Toast.makeText(getApplicationContext(),
                                result.getString("message"), Toast.LENGTH_SHORT)
                            .show();

                }

            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ExecutionException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }



        } else {

            NotificationServices.showToast(getApplicationContext(),
                    "Password not matches");

        }
    }
}
}

private boolean isEmail(String email) {

    if (email.contains("@")
            && email.contains(".")
            && email.indexOf("@") == email.lastIndexOf("@")
            && email.indexOf("@") != (email.indexOf(".") + 1)
            && (email.indexOf("@") + 1) != email.indexOf(".")
            && (!email.contains("^")) && (!email.contains(" "))
            && (!email.contains("-")) && (!email.contains("--"))) {

        return true;

    } else {

        NotificationServices.showToast(getApplicationContext(),
                "Enter correct Email.");
        return false;
    }

}

}

json.getString("member_name")

ArrayList<MyProfile> arraylist = new ArrayList<MyProfile>();

ArrayList<String> arraylist = new ArrayList<String>();

MyProfile objBeans = new MyProfile();
            objBeans.setName(json.getString("name"));
            arraylist.add(objBeans);

arraylist.add(json.getString("member_name"));

 ArrayList<MyProfile> arraylist = new ArrayList<MyProfile>();

ArrayList<String> arraylist = new ArrayList<String>(); 

arraylist.add(json.getString("member_name")); // its member_name

for(int i=0; i<array.length(); i++){ // you will get index out of bound excpetin
// index starts from 0

ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
         android.R.layout.simple_list_item_1,arraylist);
// this is just to display name

  if (status.equals("1")){

  ArrayList<MyProfile> arraylist = new ArrayList<MyProfile>();

  JSONArray array = result.getJSONArray("records");
  for(int i=0; i<array.length(); i++){
  JSONObject json = array.getJSONObject(i);
  MyProfile objBeans = new MyProfile();
  objBeans.setId(json.getString("member_id").toString());
  objBeans.setName(json.getString("member_name").toString());
  arraylist.add(mprofile);
 }

CustomAdapter adapter = new CustomAdapter(this,arraylist);

class CustomAdapter extends ArrayAdapter<MyProfile>
{
    LayoutInflater mInflater;
    ArrayList<MyProfile> list;
    public CustomAdapter(Context context,ArrayList<MyProfile> list) {
        super(context, 0,list);
        mInflater = LayoutInflater.from(context);
        this.list=list;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        if(convertView==null)
        {
            convertView= mInflater.inflate(R.layout.customlayout,parent,false);
        }
        TextView tv = (TextView) convertView.findViewById(R.id.textView1);
        MyProfile mp = list.get(position);
        tv.setText(mp.getName());
        return convertView;
    }

}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:text="TextView" />

</RelativeLayout>

 objBeans.setName(json.getString("member_id").toString());
 objBeans.setName(json.getString("member_name").toString());

@Override
protected void onCreate(Bundle savedInstanceState) {
    setContentView(R.layout.activity_my_profile);
    super.onCreate(savedInstanceState);
    mProfile = (ListView)findViewById(R.id.lvProfile);
     JSONGetRequest jRequest = JSONGetRequest
                .getSingleInstance(MyProfileActivity.this);
        jRequest.execute("http://stagging.jandeccpl.com/testing/android_traning/carpool/ws/api.php?request=login&username=1234567891&password=12345678");

}
class CustomAdapter extends ArrayAdapter<MyProfile>
    {
        LayoutInflater mInflater;
        ArrayList<MyProfile> list;
        public CustomAdapter(Context context,ArrayList<MyProfile> list) {
            super(context, 0,list);
            mInflater = LayoutInflater.from(context);
            this.list=list;
        }
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // TODO Auto-generated method stub
            if(convertView==null)
            {
                convertView= mInflater.inflate(R.layout.second,parent,false);
            }
            TextView tv = (TextView) convertView.findViewById(R.id.textView1);
            TextView tv1 = (TextView) convertView.findViewById(R.id.textView2);
            MyProfile mp = list.get(position);
            tv.setText(mp.getId());
            tv1.setText(mp.getName());
            return convertView;
        }

    }
    @Override
    public void returnjson(JSONObject result) {
        // TODO Auto-generated method stub
          try
            {
          //  JSONObject result = new JSONObject(load());

            String status = result.getString("status");

        if (status.equals("1")){

            ArrayList<MyProfile> arraylist = new ArrayList<MyProfile>();

         JSONArray array = result.getJSONArray("records");
         for(int i=0; i<array.length(); i++){
         JSONObject json = array.getJSONObject(i);
         MyProfile mprofile = new MyProfile();
         mprofile.setId(json.getString("member_id").toString());
         mprofile.setName(json.getString("member_name").toString());
         arraylist.add(mprofile);
         }  
         CustomAdapter adapter = new CustomAdapter(MyProfileActivity.this,arraylist);
         mProfile.setAdapter(adapter);
        }
            }catch(Exception e)
        {
            e.printStackTrace();
        }
    }
}

public interface Returnjson {
  public void returnjson(JSONObject json);
}

public class JSONGetRequest extends AsyncTask<String, Void, JSONObject> {

    private static Context mContext;
    private static JSONGetRequest singleInstance;
    private ProgressDialog mDialog;
    Returnjson rt;

    public static JSONGetRequest getSingleInstance(Context context) {

        singleInstance = new JSONGetRequest();

        mContext = context;

        return singleInstance;
    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        rt= (Returnjson) mContext;
        mDialog = new ProgressDialog(mContext);
        mDialog.setMessage("Please wait");
        mDialog.show();

    }

    @Override
    protected JSONObject doInBackground(String... params) {

        try {
            // Creating JSON Parser instance
            JSONParser jParser = new JSONParser();

            // getting JSON string from URL
            JSONObject json = jParser.getJSONFromUrl(params[0]);

            return json;

        } catch (Exception e) {

            System.out.println(e);
        }

        return null;

    }

    @Override
    public void onPostExecute(JSONObject result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);

        mDialog.dismiss();
        rt.returnjson(result);
    }
    }