Question

我是android的新手。现在我正在做一个应用程序。对于这个我需要将数据发送到server.Now我正在使用Volley post方法。但是当我使用齐射将数据发送到服务器时参数总是显示为null 。我附上代码请检查。我在使用片段。

代码部分

String url = "http://192.168.1.182:8084/name/registration.jsp";

    final ProgressDialog pDialog = new ProgressDialog(this.getActivity());
    pDialog.setMessage("Loading...");
    pDialog.show();    
    RequestQueue rq = Volley.newRequestQueue(getActivity().getApplicationContext());
    JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.POST,
            url, null,
            new Response.Listener<JSONObject>() {

        @Override
        public void onResponse(JSONObject response) {
            Log.d(TAG, response.toString());
            // pDialog.hide();
        }
    }, new Response.ErrorListener() {

        @Override
        public void onErrorResponse(VolleyError error) {
            VolleyLog.d(TAG, "Error: " + error.getMessage());
            //pDialog.hide();
        }
    }) {

        @Override
        protected Map<String, String> getParams() {
            Map<String, String> params = new HashMap<String, String>();
            params.put("name", "Ajay K K");
            params.put("mailid", "ajaykk50@gmail.com");
            params.put("phone", "8086327023");
            params.put("place", "Calicut");
            params.put("longitude","44444.3333");
            params.put("latitude","666666.3333");
            params.put("wheel", "1");
            params.put("type", "owner");

            return params;
        }

    };

    // Adding request to request queue
    rq.add(jsonObjReq);

Answer 1

不要覆盖getParams()。 JsonObjectRequest在构造函数中使用第三个参数来获取post参数。以下是凌空代码

中包含的文档

/**
 * Creates a new request.
 * @param method the HTTP method to use
 * @param url URL to fetch the JSON from
 * @param jsonRequest A {@link JSONObject} to post with the request. Null is allowed and
 *   indicates no parameters will be posted along with request.
 * @param listener Listener to receive the JSON response
 * @param errorListener Error listener, or null to ignore errors.
 */
public JsonObjectRequest(int method, String url, JSONObject jsonRequest,
        Listener<JSONObject> listener, ErrorListener errorListener) {
    super(method, url, (jsonRequest == null) ? null : jsonRequest.toString(), listener,
                errorListener);
}

使用这样的。

String url = "http://192.168.1.182:8084/name/registration.jsp";

final ProgressDialog pDialog = new ProgressDialog(this.getActivity());
pDialog.setMessage("Loading...");
pDialog.show();    
RequestQueue rq = Volley.newRequestQueue(getActivity().getApplicationContext());

JSONObject params = new JSONObject();
try {
    params.put("name", "Ajay K K");
    params.put("mailid", "ajaykk50@gmail.com");
    params.put("phone", "8086327023");
    params.put("place", "Calicut");
    params.put("longitude","44444.3333");
    params.put("latitude","666666.3333");
    params.put("wheel", "1");
    params.put("type", "owner");
} catch (JSONException e) {
    e.printStackTrace();
}

JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.POST,
        url, params, //Not null.
        new Response.Listener<JSONObject>() {

    @Override
    public void onResponse(JSONObject response) {
        Log.d(TAG, response.toString());
        // pDialog.hide();
    }
}, new Response.ErrorListener() {

    @Override
    public void onErrorResponse(VolleyError error) {
        VolleyLog.d(TAG, "Error: " + error.getMessage());
        //pDialog.hide();
    }
});

// Adding request to request queue
rq.add(jsonObjReq);

Answer 2

import com.android.volley.NetworkResponse;
import com.android.volley.ParseError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.Response.ErrorListener;
import com.android.volley.Response.Listener;
import com.android.volley.toolbox.HttpHeaderParser;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.UnsupportedEncodingException;
import java.util.Map;

public class CustomRequest extends Request<JSONObject> {

private Listener<JSONObject> listener;
private Map<String, String> params;

public CustomRequest(String url, Map<String, String> params,
                     Listener<JSONObject> reponseListener, ErrorListener errorListener) {
    super(Method.GET, url, errorListener);
    this.listener = reponseListener;
    this.params = params;
}

public CustomRequest(int method, String url, Map<String, String> params,
                     Listener<JSONObject> reponseListener, ErrorListener errorListener) {
    super(method, url, errorListener);
    this.listener = reponseListener;
    this.params = params;
}

protected Map<String, String> getParams()
        throws com.android.volley.AuthFailureError {
    return params;
}

;

@Override
protected Response<JSONObject> parseNetworkResponse(NetworkResponse response) {
    try {
        String jsonString = new String(response.data,
                HttpHeaderParser.parseCharset(response.headers));
        return Response.success(new JSONObject(jsonString),
                HttpHeaderParser.parseCacheHeaders(response));
    } catch (UnsupportedEncodingException e) {
        return Response.error(new ParseError(e));
    } catch (JSONException je) {
        return Response.error(new ParseError(je));
    }
}

@Override
protected void deliverResponse(JSONObject response) {
    // TODO Auto-generated method stub
    listener.onResponse(response);
    }
}

之后从您的活动中调用此课程......就像这样

 RequestQueue requestQueue = VolleySingleton.getInstance().getRequestQueue();
        CustomRequest jsObjRequest = new CustomRequest(Request.Method.POST, LOGIN_URL, params, new Response.Listener<JSONObject>() {

            @Override
            public void onResponse(JSONObject response) {
                Log.d("RESPONSE", response.toString());

            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d("RESPONSE ERROR", "Error: " + error.getMessage());

            }
        });

        requestQueue.add(jsObjRequest);

您可以创建参数

 Map<String, String> params = new HashMap<String, String>();
        params.put("email", "yourEmail");
        params.put("password", "yourPassword");

您需要的其他课程是＆＃34; VolleySingleton＆＃34;和＆＃34; RetriveMyApplicationContext＆＃34;

    import android.graphics.Bitmap;
import android.util.LruCache;

import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.Volley;


public class VolleySingleton {

private static VolleySingleton sInstance = null;
private RequestQueue mRequestQueue;
private ImageLoader imageLoader;

private VolleySingleton() {
    mRequestQueue = Volley.newRequestQueue(RetriveMyApplicationContext.getAppContext());

    imageLoader = new ImageLoader(mRequestQueue, new ImageLoader.ImageCache() {

        private LruCache<String, Bitmap> cache = new LruCache<>((int) (Runtime.getRuntime().maxMemory() / 1024 / 8));

        @Override
        public Bitmap getBitmap(String url) {
            return cache.get(url);
        }

        @Override
        public void putBitmap(String url, Bitmap bitmap) {
            cache.put(url, bitmap);
        }
    });

}

public static VolleySingleton getInstance() {
    if (sInstance == null) {
        sInstance = new VolleySingleton();
    }
    return sInstance;
}

public RequestQueue getRequestQueue() {
    return mRequestQueue;
}

public ImageLoader getImageLoader() {
    return imageLoader;
}
}

RetriveMyApplicationContext类

public class RetriveMyApplicationContext extends Application {


//Don't forget to mention RetriveMyApplicationContext Class in Manifests File otherwise it will throw NullPointer Exception
// <application
// android:name=".volley.RetriveMyApplicationContext"


private static RetriveMyApplicationContext mRetriveMyApplicationContext;

@Override
public void onCreate() {
    super.onCreate();
    mRetriveMyApplicationContext = this;
}

public static RetriveMyApplicationContext getInstance() {

    return mRetriveMyApplicationContext;
}

public static Context getAppContext() {

    return mRetriveMyApplicationContext.getApplicationContext();
}
}

Answer 3

public class CustomJsonRequest extends Request {

Map<String, String> params;       
private Response.Listener listener; 

public CustomJsonRequest(int requestMethod, String url, Map<String, String> params,
                      Response.Listener responseListener, Response.ErrorListener errorListener) {

    super(requestMethod, url, errorListener);
    this.params = params;
    this.listener = responseListener;
}

@Override
protected void deliverResponse(Object response) {
    listener.onResponse(response); 

}

@Override
public Map<String, String> getParams() throws AuthFailureError {
         return params;
}

@Override
protected Response parseNetworkResponse(NetworkResponse response) {
    try {
        String jsonString = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
        return Response.success(new JSONObject(jsonString),
        HttpHeaderParser.parseCacheHeaders(response));
    } catch (UnsupportedEncodingException e) {
        return Response.error(new ParseError(e));
    } catch (JSONException je) {
        return Response.error(new ParseError(je));
    }
}

}

Answer 4

我也遇到了这种错误，我浪费了半天来解决这个问题。最后我解决了。

这不是Android代码问题，请检查您发送给服务器的参数以及检查数据库中的列。如果在数据库中找不到我们收到此错误的列。

Android Volley POST发送参数始终为null

4 个答案: