private void doClockInOut(JSONObject params) {        Response.Listener
     
       okListener = new Response.Listener
      
       () {            @Override            public void onResponse(JSONObject response) {                try {                    Log.e(service, response.getString("Status"));                    if ("1".equals(response.getString("Status"))) {                        success = true;                    } else if ("-4".equals(response.getString("Status"))) {                        View.OnClickListener listener = new View.OnClickListener() {                            @Override                            public void onClick(View v) {                                PersistenceUtils.getSharedInstance().put("login", "0");                                MainActivity.act.startActivity(new Intent(MainActivity.act, LoginActivity.class));                                MainActivity.act.finish();                            }                        };                        MessageDialog.showMessageDialogTwoButton(MainActivity.act, response.getString("Message"), "Cancel", "Login", listener);                    } else {                        error = true;                        //MessageDialog.showMessageDialog(MainActivity.act, response.getString("Message"));                    }                } catch (Exception e) {                    e.printStackTrace();                }            }        };        VolleyUtils.getSharedInstance().init(MainActivity.act);        VolleyUtils.getSharedInstance().requestService(MainActivity.act.getString(R.string.ws_url) + service +  ".json", params, okListener, errorListener);    }    private void doOther(Map
       
         params) {        Response.Listener
        
          okListener = new Response.Listener
         
          () {            @Override            public void onResponse(String response) {                try {                    Log.e(service, response);                    if ("true".equals(response)) {                        success = true;                    }                } catch (Exception e) {                    Log.e(service, e.toString());                }            }        };        VolleyUtils.getSharedInstance().init(MainActivity.act);        VolleyUtils.getSharedInstance().requestService1(MainActivity.act.getString(R.string.ws_url) + service +  ".json", params, okListener, errorListener);    }    Response.ErrorListener errorListener = new Response.ErrorListener() {        @Override        public void onErrorResponse(VolleyError error) {            if (VolleyUtils.getSharedInstance().getMessage(error) != null)                Log.e(service, VolleyUtils.getSharedInstance().getMessage(error));        }    };
         
        
       
      
     

　　

package com.baclock.utils;import android.app.Activity;import android.content.Context;import com.android.volley.AuthFailureError;import com.android.volley.DefaultRetryPolicy;import com.android.volley.NetworkError;import com.android.volley.NoConnectionError;import com.android.volley.Request;import com.android.volley.RequestQueue;import com.android.volley.Response;import com.android.volley.ServerError;import com.android.volley.TimeoutError;import com.android.volley.VolleyError;import com.android.volley.toolbox.JsonObjectRequest;import com.android.volley.toolbox.StringRequest;import com.android.volley.toolbox.Volley;import com.baclock.R;import org.json.JSONArray;import org.json.JSONObject;import java.util.Map;/** * Created by Jack on 1/13/2016. */public class VolleyUtils {    private static VolleyUtils sharedInstance = null;    private RequestQueue requestQueue = null;    private String tag;    private int time_out_ms = 10000;    public static VolleyUtils getSharedInstance() {        if (sharedInstance == null) {            sharedInstance = new VolleyUtils();        }        return sharedInstance;    }    public void init(Activity act) {        if (requestQueue == null) {            requestQueue = Volley.newRequestQueue(act);            tag = act.getString(R.string.app_name);        }    }    public void requestService(String url, JSONObject param, Response.Listener
     
       OkListener, Response.ErrorListener errorListener) {        JsonObjectRequest jsonObjRequest = new JsonObjectRequest(Request.Method.POST, url, param, OkListener, errorListener);        jsonObjRequest.setRetryPolicy(new DefaultRetryPolicy(time_out_ms, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));        jsonObjRequest.setTag(tag);        requestQueue.add(jsonObjRequest);    }    public void JsonArrayRequestService(String url, JSONObject param, Response.Listener
      
        OkListener, Response.ErrorListener errorListener) {        JsonArrayRequest request = new JsonArrayRequest(Request.Method.POST, url, param, OkListener, errorListener);        request.setRetryPolicy(new DefaultRetryPolicy(time_out_ms, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));        request.setTag(tag);        requestQueue.add(request);    }    public void requestService1(String url, final Map
       
         param, Response.Listener
        
          OkListener, Response.ErrorListener errorListener) {        StringRequest stringRequest = new StringRequest(Request.Method.POST, url, OkListener, errorListener) {            @Override            protected Map
         
           getParams() {                return param;            }        };        stringRequest.setRetryPolicy(new DefaultRetryPolicy(time_out_ms, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));        stringRequest.setTag(tag);        requestQueue.add(stringRequest);    }    public String getMessage(VolleyError error) {        if (error instanceof TimeoutError) {            return "The request time out!";        } else if (isServerProblem(error)) {            return "Server is error";        } else if (isNetworkProblem(error)) {            return "Network is error, please check your internet!";        } else if (error.getMessage().startsWith("org.json.JSONException")) {            return null;        } else {//          if (error != null && error.getMessage() != null)//              return error.getMessage();//          else//              return "Carrot error";            return error.getMessage();        }    }    private boolean isNetworkProblem(Object error) {        return (error instanceof NetworkError) || (error instanceof NoConnectionError);    }    private boolean isServerProblem(Object error) {        return (error instanceof ServerError) || (error instanceof AuthFailureError);    }}