Hello Im writing an app in which client sends name of room to server, server creates it and then sends back whole list of rooms. I have problem with receiving this object from server also whats interesting when I close clients' app and open again I have list of rooms just like it should be. I refresh room list in client app but its always empty only reopening helps that's pretty weird and I don't know an issue of this.
On client side:
getIs() method is returning is object
getOs() method returning os object
this.os = new ObjectOutputStream(clientSocket.getOutputStream());
this.is = new ObjectInputStream(clientSocket.getInputStream());
private void createRoom(ActionEvent event) {
String roomName = "CreateRoom ";
roomName += setRoomName();
String response = null;
try {
client.getOs().writeObject(roomName);
response = (String) client.getIs().readObject();
System.out.println(response);
} catch (IOException | ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void refreshRooms() {
String response = null;
try {
client.getOs().writeObject("RefreshRooms");
response = (String) client.getIs().readObject();
System.out.println(response);
rooms = (Rooms) client.getIs().readObject();
System.out.println("Print in client: ");
rooms.printAllRooms();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Server:
this.os = new ObjectOutputStream(connection.getOutputStream());
this.is = new ObjectInputStream(connection.getInputStream());
public void run() {
String inputRequest = null;
try {
while((inputRequest = (String) ois.readObject()) != null) {
System.out.println(inputRequest);
handleRequest(inputRequest);
}
} catch (IOException | ClassNotFoundException e) {
System.out.println("Client has disconnected.");
e.printStackTrace();
}
}
private void handleRequest(String request) {
String response = null;
String[] msg = request.split(" ");
if(msg[0].equals("CreateRoom")) {
try {
oos.writeObject("You want create a room.");
Room newRoom = new Room(msg[1]);
rooms.addRoom(newRoom);
System.out.println("Created room: " + newRoom.getName());
System.out.println("\n Print after creation: ");
rooms.printAllRooms();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}else if (msg[0].equals("RefreshRooms")) {
try {
oos.writeObject("You want list of rooms.");
System.out.println("Print before send.");
rooms.printAllRooms();
oos.writeObject(rooms);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
///EDIT:
So I removed PrintWriter and BufferedReader objects and now Im using only Object Streams. What doesn't work now is:
I create some rooms one after another and then refresh rooms list on clients app - in that case I get all rooms
But when I create one room refresh then create another and refresh I get only 1 room after 2nd refresh, so basically when I refresh server sends me always the same object from 1st send and I don't know how to change it.
Also Im printing these rooms on server side and always get all rooms so room creation is OK.
You could try to flush the buffered streams:
os.flush()
This will force the stream to actually send the bytes of the serialized object. Without that, the BufferedOutputStream might just wait around and buffer data, as the name says. This is done so that the size of the sent packets does not become too small, which would result in a lot of overhead if you want to send multiple objects.
If you are done, you should close the stream anyway.
I am creating an application that makes calls to the Hitbox API. I am trying to get the game name (listed as category_name from a list.
Thus far, I have managed to get the game name one time during the programs running stage, however when I change where to get the game name from, the program doesn't do anything. I am at a loss as to what could cause it not to send another request to the server.
public void apiConnect(){
String channel = text.getText();
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet("http://api.hitbox.tv/media/live/" + channel);
HttpResponse response = null;
try {
response = client.execute(request);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// Get the response
BufferedReader rd = null;
try {
rd = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));
} catch (UnsupportedOperationException | IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String line = "";
try {
while ((line = rd.readLine()) != null) {
hitbox.append(line);
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
FileUtils.writeStringToFile(new File("hitbox.json"), hitbox.getText());
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
String game = null;
FileInputStream fileHitbox = null;
try {
fileHitbox = new FileInputStream(new File("hitbox.json"));
} catch (FileNotFoundException e2) {
// TODO Auto-generated catch block
e2.printStackTrace();
}
String strHitbox = null;
try {
strHitbox = IOUtils.toString(fileHitbox, "UTF-8");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
JSONObject obj = new JSONObject(strHitbox);
JSONArray ar = obj.getJSONArray("livestream");
for (int i = 0; i < ar.length(); i++)
{
game = ar.getJSONObject(i).getString("category_name");
nameOf.setText("Game Name: " + game);
}
File hb = new File("hitbox.json");
if(hb.exists()){
hb.delete();
}
}
The above sample is the defined function, and the Get Game Name button code is below:
btnGetGameName.addSelectionListener(new SelectionAdapter() {
#Override
public void widgetSelected(SelectionEvent e) {
apiConnect();
}
});
Could anyone suggest what is causing it to not work after the first request, and if possible suggest a solution?
EDIT: I have found the issue. The reading of the data from the API is appended to the hitbox variable. I have thus added a snippet that clears what "hitbox" variable has when the button is pressed, thus meaning the code works without issues.
Try to consume your response after your read it to release the resource :
rd = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));
response.getEntity().consumeContent();
//Or if you have EntityUtils
EntityUtils.consume(response.getEntity());
source
okay so i created a inner class which extends AsycTask in order for my code to run outwith the UI thread. However i'm getting this error so i assume this means some part of my onPostExecute needs to be done in doInBackground however i cant figure out exactly what this is
public class asyncTask extends AsyncTask<String, Integer, String> {
ProgressDialog dialog = new ProgressDialog(PetrolPriceActivity.this);
#Override
protected void onPreExecute() {
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setProgress(0);
dialog.setMax(100);
dialog.setMessage("loading...");
dialog.show();
}
#Override
protected String doInBackground(String...parmans){
{
for(int i = 0; i < 100; i++){
publishProgress(1);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String urlString = petrolPriceURL;
String result = "";
InputStream anInStream = null;
int response = -1;
URL url = null;
try {
url = new URL(urlString);
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
return null;
}
URLConnection conn = null;
try {
conn = url.openConnection();
} catch (IOException e) {
// TODO Auto-generated catch block
return null;
}
// Check that the connection can be opened
if (!(conn instanceof HttpURLConnection))
try {
throw new IOException("Not an HTTP connection");
} catch (IOException e) {
// TODO Auto-generated catch block
return null;
}
try
{
// Open connection
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
// Check that connection is OK
if (response == HttpURLConnection.HTTP_OK)
{
// Connection is OK so open a reader
anInStream = httpConn.getInputStream();
InputStreamReader in= new InputStreamReader(anInStream);
BufferedReader bin= new BufferedReader(in);
// Read in the data from the RSS stream
String line = new String();
while (( (line = bin.readLine())) != null)
{
result = result + "\n" + line;
}
}
}
catch (IOException ex)
{
try {
throw new IOException("Error connecting");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return result;
}
}
#Override
protected void onProgressUpdate(Integer...progress){
dialog.incrementProgressBy(progress[0]);
}
#Override
protected void onPostExecute(String result) {
// Get the data from the RSS stream as a string
errorText = (TextView)findViewById(R.id.error);
response = (TextView)findViewById(R.id.title);
try
{
// Get the data from the RSS stream as a string
result = doInBackground(petrolPriceURL);
response.setText(result);
Log.v(TAG, "index=" + result);
}
catch(Exception ae)
{
// Handle error
errorText.setText("Error");
// Add error info to log for diagnostics
errorText.setText(ae.toString());
}
if(dialog.getProgress() == dialog.getMax())
dialog.dismiss();
}
}
if someone could point out my error as well as show an example of where the code is suppose to go in my doInBackground that would be great. Thanks
problem:
result = doInBackground(petrolPriceURL);
you are implicitly calling the doInbackground method in the onPostExecute which will actually run in your UI thread instead on a different thread thus resulting to Android:NetworkOnMainThreadException.
Also it is unnecessary to call doInBackground that it is already executed before onPostExecute when you execute your Asynctask. Just directly use the result parameter of the onPostExecute.
sample:
#Override
protected void onPostExecute(String result) {
// Get the data from the RSS stream as a string
errorText = (TextView)findViewById(R.id.error);
response = (TextView)findViewById(R.id.title);
response.setText(result);
if(dialog.getProgress() == dialog.getMax())
dialog.dismiss();
}
I suspect the error is related to this part of your code:
try
{
// Get the data from the RSS stream as a string
result = doInBackground(petrolPriceURL);
response.setText(result);
Log.v(TAG, "index=" + result);
}
doInBackgound is called automatically when you call asynctask.execute. To start your task correctly you should (1) create a new instance of your task; (2) pass the string params you need to use in doInBackground in the execute method; (3) use them; (4) return the result to onPostExecute.
For Example:
//in your activity or fragment
MyTask postTask = new MyTask();
postTask.execute(value1, value2, value3);
//in your async task
#Override
protected String doInBackground(String... params){
//extract values
String value1 = params[0];
String value2 = params[1];
String value3 = params[2];
// do some work and return result
return value1 + value2;
}
#Override
protected void onPostExecute(String result){
//use the result you returned from you doInBackground method
}
You should try to do all of your "work" in the doInBackground method. Reutrn the result you want to use on the main/UI thread. This will automaticlly be passed as an argument to the onPostExecute method (which runs on the main/UI thread).
This question already has answers here:
How do I parse JSON in Android? [duplicate]
(3 answers)
Closed 8 years ago.
I am encounter a problem. I have following xml
<string>[{"BatchIDs":[],"HomeWorkCategoryName":"","FileURL":"","FileName":"","ID":1,"Title":"test","Description":"test","HomeworkCategoryID":1,"ExpiryDate":"\/Date(1386658800000)\/","FileID":-2147483648,"URL":"","Mode":1,"Type":2,"Status":1,"CreatedOnDate":"\/Date(1388093500883)\/","UpdatedOnDate":"\/Date(1388093500883)\/","Inactive":false,"Deleted":true},
{"BatchIDs":[],"HomeWorkCategoryName":"","FileURL":"","FileName":"","ID":1,"Title":"test","Description":"test","HomeworkCategoryID":1,"ExpiryDate":"\/Date(1386658800000)\/","FileID":-2147483648,"URL":"","Mode":1,"Type":2,"Status":1,"CreatedOnDate":"\/Date(1388093500883)\/","UpdatedOnDate":"\/Date(1388093500883)\/","Inactive":false,"Deleted":true},
{"BatchIDs":[],"HomeWorkCategoryName":"","FileURL":"","FileName":"","ID":1,"Title":"test","Description":"test","HomeworkCategoryID":1,"ExpiryDate":"\/Date(1386658800000)\/","FileID":-2147483648,"URL":"","Mode":1,"Type":2,"Status":1,"CreatedOnDate":"\/Date(1388093500883)\/","UpdatedOnDate":"\/Date(1388093500883)\/","Inactive":false,"Deleted":true}]
And I want to read all values passed in this xml. This xml is single string return by web service. Currently I am using following code (it's also providing null value for first entry)
Object result = envelope.getResponse();
str=result+"";
String key,value;
String[] couple = str.split(",\"");
for(int i =0; i < couple.length ; i++) {
String[] items =couple[i].split(":");
key=items[0];
value=items[1];
key=key.replaceAll("\"", "");
value=value.replaceAll("\"", "");
/* some conditions to fetch values */
}
Please tell me how can I get exact values and keys in android.
Thanks,
It seems to be a valid json. You can use http://jsonlint.com/ to check that.
So with this following class : JSONArray, you can retrieve what you want.
Thanks everyone for helping me.
Here is my soluction through I overcome my problem. May be it will use for others
HttpGet httpRequest = new HttpGet(_URL);
HttpClient httpclient = new DefaultHttpClient();
HttpResponse httpresponse = httpclient.execute(httpRequest);
JSONArray response = null;
try {
response = new JSONArray(getJSONString(httpresponse));
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
for (int i = 0; i < response.length(); i++) {
try {
//your values
String _name=response.getJSONObject(i).getString("NAME");
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Here is 2nd function.If your function is parse through xml code.
public static String getJSONString(HttpResponse response) {
try {
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = builder.parse(response.getEntity().getContent());
NodeList nl = doc.getElementsByTagName("string");
Node n = nl.item(0);
String str = n.getFirstChild().getNodeValue();
return str;
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
Happy Coding
I'm currently using the library JSON-io. I created a desktop application which when a person want to log in in the system send an JSONObject with his username and password. Then the server send back the response if the person is allowed or not (also a JSONObject). Until here everything works fine.
Now i want to make an Android app. I take the same code than before for login but the application crashes.
The code for login is launch from an AsyncTask and i put the permission to access to Internet to the Manifest.
I perform some testing and it occurs that the method write of JSONWriter "delete" my JSON because on the server side he receives this : {}. I tried to hardcode the JSONObject on the server side (the server's code works fine because we can use the desktop app) but this time the readObject on the android App receives also {}.
We tried to send jsonObject.toString() and this time it worked (except that the server isn't configured to handle a string).
Do anyone knows why on android the two methods write and readObject are deleting the JSON ?
Thank you.
EDIT:
Here the code i wrote:
On the android App
protected Boolean doInBackground(Void... params) {
// 3 : create a JSON object and send it to server for verification
JSONObject loginJS = new JSONObject();
try {
loginJS.put("type", Type.LOGIN); // Type is an enum
loginJS.put("username", userName);
loginJS.put("hash", mPassword);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
User user = new User();
System.out
.println("User created and ready to connect to the spu for login");
user.connexionToSPU(); // This method works
System.out.println("LoginJS = "+loginJS.toString()); At this point the print of the JSON is fine we have {"type":"Login", ....}
user.sendToSPU(loginJS); //This is where there's a problem
// 4 : wait response
JSONObject loginResponseJS = user.receiveFromSPU(); // And when i hard code the JSON on the server side receiveFromSPU get a empty JSON
Method connexionToSPU:
public void connexionToSPU() {
jswSPU = null;
jsrSPU = null;
Socket socket = null;
try {
socket = new Socket(prop.readPropertiesXML("IP_adress_server"),
Integer.parseInt(prop.readPropertiesXML("port_server")));
} catch (NumberFormatException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (UnknownHostException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
try {
jswSPU = new JsonWriter(socket.getOutputStream());
jsrSPU = new JsonReader(new BufferedInputStream(socket.getInputStream()));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
sendToSPU method
public void sendToSPU(JSONObject json) {
try {
jswSPU.write(json);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
ReceiveFromSPU method
public JSONObject receiveFromSPU() {
JSONObject json = null;
try {
json = (JSONObject) jsrSPU.readObject();
System.out.println("JSON FROM THE SERVER : "+json.toString());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return json;
}
Hope it will be sufficiently clear.
Thank you