Обычно ошибка, возникающая при сбое в работе базы данных базы данных, поэтому не забудьте подключить вашу базу данных или включить файл базы данных.
include_once(db_connetc.php');
ИЛИ
// Create a connection
$connection = mysql_connect("localhost", "root", "") or die(mysql_error());
//Select database
mysql_select_db("db_name", $connection) or die(mysql_error());
$employee_query = "SELECT * FROM employee WHERE `id` ='".$_POST['id']."';
$employee_data = mysql_query($employee_query);
if (mysql_num_rows($employee_data) > 0) {
while ($row = mysql_fetch_array($employee_data)){
echo $row['emp_name'];
} // end of while loop
} // end of if
mysql_query($query_variable);
. JsonObjectRequest
фактически принимает JSONObject
как тело.
Из эта статья в блоге ,
final String url = "some/url";
final JSONObject jsonBody = new JSONObject("{\"type\":\"example\"}");
new JsonObjectRequest(url, jsonBody, new Response.Listener<JSONObject>() { ... });
Вот источник код и JavaDoc (@param jsonRequest
):
/**
* 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);
}
RequestQueue
. RequestQueue queue = Volley.newRequestQueue(this);
StringRequest
с помощью прослушивателя ответов и ошибок. StringRequest sr = new StringRequest(Request.Method.POST,"http://api.someservice.com/post/comment", new Response.Listener<String>() {
@Override
public void onResponse(String response) {
mPostCommentResponse.requestCompleted();
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
mPostCommentResponse.requestEndedWithError(error);
}
}){
@Override
protected Map<String,String> getParams(){
Map<String,String> params = new HashMap<String, String>();
params.put("user",userAccount.getUsername());
params.put("pass",userAccount.getPassword());
params.put("comment", Uri.encode(comment));
params.put("comment_post_ID",String.valueOf(postId));
params.put("blogId",String.valueOf(blogId));
return params;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String,String> params = new HashMap<String, String>();
params.put("Content-Type","application/x-www-form-urlencoded");
return params;
}
};
RequestQueue
. queue.add(jsObjRequest);
PostCommentResponseListener
, чтобы вы могли его видеть. Это простой делегат для запроса async. public interface PostCommentResponseListener {
public void requestStarted();
public void requestCompleted();
public void requestEndedWithError(VolleyError error);
}
AndroidManifest.xml
. <uses-permission android:name="android.permission.INTERNET"/>
Вы также можете отправлять данные, переопределяя метод getBody()
класса JsonObjectRequest
. Как показано ниже.
@Override
public byte[] getBody()
{
JSONObject jsonObject = new JSONObject();
String body = null;
try
{
jsonObject.put("username", "user123");
jsonObject.put("password", "Pass123");
body = jsonObject.toString();
} catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
try
{
return body.toString().getBytes("utf-8");
} catch (UnsupportedEncodingException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
final String URL = "/volley/resource/12";
// Post params to be sent to the server
HashMap<String, String> params = new HashMap<String, String>();
params.put("token", "AbCdEfGh123456");
JsonObjectRequest req = new JsonObjectRequest(URL, new JSONObject(params),
new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
VolleyLog.v("Response:%n %s", response.toString(4));
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.e("Error: ", error.getMessage());
}
});
// add the request object to the queue to be executed
ApplicationController.getInstance().addToRequestQueue(req);
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
JSONObject JObj = new JSONObject();
try {
JObj.put("Id","1");
JObj.put("Name", "abc");
} catch (Exception e) {
e.printStackTrace();
}
params.put("params", JObj.toString());
// Map.Entry<String,String>
Log.d("Parameter", params.toString());
return params;
}
Я знаю, что эта ветка довольно старая, но у меня была эта проблема, и я придумал классное решение, которое может быть очень полезным для многих, потому что оно исправляет / расширяет библиотеку Volley по многим аспектам.
Я заметил некоторые неработающие функции Volley:
JSONObjectRequest
не идеален: в конце вы должны ожидать JSON
(см. Response.Listener<JSONObject>
). ResponseListener
? Я более или менее скомпилировал множество решений в большом родовом классе, чтобы иметь решение для всей проблемы, которую я цитировал.
/**
* Created by laurentmeyer on 25/07/15.
*/
public class GenericRequest<T> extends JsonRequest<T> {
private final Gson gson = new Gson();
private final Class<T> clazz;
private final Map<String, String> headers;
// Used for request which do not return anything from the server
private boolean muteRequest = false;
/**
* Basically, this is the constructor which is called by the others.
* It allows you to send an object of type A to the server and expect a JSON representing a object of type B.
* The problem with the #JsonObjectRequest is that you expect a JSON at the end.
* We can do better than that, we can directly receive our POJO.
* That's what this class does.
*
* @param method: HTTP Method
* @param classtype: Classtype to parse the JSON coming from the server
* @param url: url to be called
* @param requestBody: The body being sent
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
private GenericRequest(int method, Class<T> classtype, String url, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
super(method, url, requestBody, listener,
errorListener);
clazz = classtype;
this.headers = headers;
configureRequest();
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, headers);
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, new HashMap<String, String>());
}
/**
* Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param requestBody: String to be sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(method, classtype, url, requestBody, listener,
errorListener, new HashMap<String, String>());
}
/**
* Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (Without header)
*
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
*/
public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener) {
this(Request.Method.GET, url, classtype, "", listener, errorListener);
}
/**
* Method to be called if you want to GET something from the server and receive the POJO directly after the call (no JSON). (With headers)
*
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
*/
public GenericRequest(String url, Class<T> classtype, Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers) {
this(Request.Method.GET, classtype, url, "", listener, errorListener, headers);
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (with headers and muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param headers: Added headers
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, Map<String, String> headers, boolean mute) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, headers);
this.muteRequest = mute;
}
/**
* Method to be called if you want to send some objects to your server via body in JSON of the request (without header and muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param toBeSent: Object which will be transformed in JSON via Gson and sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, Object toBeSent,
Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
this(method, classtype, url, new Gson().toJson(toBeSent), listener,
errorListener, new HashMap<String, String>());
this.muteRequest = mute;
}
/**
* Method to be called if you want to send something to the server but not with a JSON, just with a defined String (without header and not muted)
*
* @param method: HTTP Method
* @param url: URL to be called
* @param classtype: Classtype to parse the JSON returned from the server
* @param requestBody: String to be sent to the server
* @param listener: Listener of the request
* @param errorListener: Error handler of the request
* @param mute: Muted (put it to true, to make sense)
*/
public GenericRequest(int method, String url, Class<T> classtype, String requestBody,
Response.Listener<T> listener, Response.ErrorListener errorListener, boolean mute) {
this(method, classtype, url, requestBody, listener,
errorListener, new HashMap<String, String>());
this.muteRequest = mute;
}
@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
// The magic of the mute request happens here
if (muteRequest) {
if (response.statusCode >= 200 && response.statusCode <= 299) {
// If the status is correct, we return a success but with a null object, because the server didn't return anything
return Response.success(null, HttpHeaderParser.parseCacheHeaders(response));
}
} else {
try {
// If it's not muted; we just need to create our POJO from the returned JSON and handle correctly the errors
String json = new String(response.data, HttpHeaderParser.parseCharset(response.headers));
T parsedObject = gson.fromJson(json, clazz);
return Response.success(parsedObject, HttpHeaderParser.parseCacheHeaders(response));
} catch (UnsupportedEncodingException e) {
return Response.error(new ParseError(e));
} catch (JsonSyntaxException e) {
return Response.error(new ParseError(e));
}
}
return null;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
return headers != null ? headers : super.getHeaders();
}
private void configureRequest() {
// Set retry policy
// Add headers, for auth for example
// ...
}
}
Это может показаться немного излишним, но это довольно классно иметь все эти конструкторы, потому что у вас есть все случаи:
(Основной конструктор не предназначался для непосредственного использования, хотя это, конечно, возможно).
Конечно, для того, чтобы это сработало, у вас должен быть Google GSON Lib ; просто добавьте:
compile 'com.google.code.gson:gson:x.y.z'
к вашим зависимостям (текущая версия 2.3.1
).
final String url = "some/url";
вместо:
final JSONObject jsonBody = "{\"type\":\"example\"}";
вы можете использовать:
JSONObject jsonBody = new JSONObject();
try {
jsonBody.put("type", "my type");
} catch (JSONException e) {
e.printStackTrace();
}
new JsonObjectRequest(url, jsonBody, new Response.Listener<JSONObject>() { ... });
final Map<String,String> params = new HashMap<String,String>();
params.put("email", customer.getEmail());
params.put("password", customer.getPassword());
String url = Constants.BASE_URL+"login";
doWebRequestPost(url, params);
public void doWebRequestPost(String url, final Map<String,String> json){
getmDialogListener().showDialog();
StringRequest post = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
try {
getmDialogListener().dismissDialog();
response....
} catch (Exception e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Log.d(App.TAG,error.toString());
getmDialogListener().dismissDialog();
}
}){
@Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> map = json;
return map;
}
};
App.getInstance().getRequestQueue().add(post);
}