We Keep Coding

Send data(Client_id=1,Staff_id=2) from android application to tomcat server

i want to send data from android application to tomcat java server.
Data is just one is client_id which is 1 and second is staff_id which is 2.
after authenticate the client id and staff id from tomcat show me a toast of success....please help...
Code is here
public class MyAsyncTasks extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// display a progress dialog for good user experiance
}
#Override
protected String doInBackground(String... params) {
// implement API in background and store the response in current variable
String current = "";
try {
URL url;
HttpURLConnection urlConnection = null;
try {
url = new URL("http://192.168.1.13:8080/digitaldisplay/s/m/data");
urlConnection = (HttpURLConnection) url
.openConnection();
InputStream in = urlConnection.getInputStream();
InputStreamReader isw = new InputStreamReader(in);
int data = isw.read();
while (data != -1) {
current += (char) data;
data = isw.read();
System.out.print(current);
}
// return the data to onPostExecute method
return current;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
}
} catch (Exception e) {
e.printStackTrace();
return "Exception: " + e.getMessage();
}
return current;
}
#Override
protected void onPostExecute(String s) {
Toast.makeText(Register.this, "success", Toast.LENGTH_SHORT).show();
Log.d("data", s.toString());
// dismiss the progress dialog after receiving data from API
try {
// JSON Parsing of data
JSONArray jsonArray = new JSONArray(s);
JSONObject oneObject = jsonArray.getJSONObject(0);
// Pulling items from the array
client = Integer.parseInt(oneObject.getString("client"));
staff = Integer.parseInt(oneObject.getString("staff"));
} catch (JSONException e) {
e.printStackTrace();
}
} }}

The logic in your code looks off to me. This is the pattern I usually follow when making a REST call from an activity using HttpURLConnection:
try {
String endpoint = "http://192.168.1.13:8080/digitaldisplay/s/m/data";
URL obj = new URL(endpoint);
HttpURLConnection con = (HttpURLConnection) obj.openConnection();
con.setRequestMethod("POST"); // but maybe you want GET here...
con.setConnectTimeout(10000);
con.setDoInput(true);
con.setDoOutput(true);
JSONObject inputJSON = new JSONObject();
inputJSON.put("Client_id", 1);
inputJSON.put("Staff_id", 2);
con.setRequestProperty("Content-Type", "application/json; charset=UTF-8");
OutputStream os = con.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(inputJSON.toString());
writer.flush();
writer.close();
os.close();
int responseCode = con.getResponseCode();
BufferedReader in = new BufferedReader(
new InputStreamReader(con.getInputStream()));
String inputLine;
StringBuffer response = new StringBuffer();
while ((inputLine = in.readLine()) != null) {
response.append(inputLine);
}
in.close();
System.out.println(response);
} catch (SocketTimeoutException se) {
// handle timeout exception
responseCode = -1;
} catch (Exception e) {
// handle general exception
responseCode = 0;
}
The only major change in adapting the above code for GET would be that you wouldn't write your input data to the connection. Instead, you would just append query parameters to the URL. I am possibly guessing that you need POST here, since your URL doesn't have any query parameters in it.

Delivering data between two classes

I'm trying search a beacon device and get the Majoy & Minor, then send the data to request, but I got the problems is I don't know how to send the data between the two part ..
I want to put the beacon.getMajor()
to jsonObject.put("uuid", a)
Thank you !
Here is my code.
private List<String> placesNearBeacon(Beacon beacon) {
int a = beacon.getMajor();
final String b = String.valueOf(beacon.getMajor());
Log.v("show", String.valueOf(a));
Intent intent = new Intent(this,AsyncLogin.class);
intent.putExtra("MAJOR",a);
startActivity(intent);
if (a == 258){
new AsyncLogin().execute(String.valueOf(a));
}
String beaconKey = String.format("%d:%d", beacon.getMajor(), beacon.getMinor());
return Collections.emptyList();
}
enter code here
private class AsyncLogin extends AsyncTask<String, String, String>
{
HttpURLConnection conn;
URL url = null;
Uri a = new Intent().getData();
#Override
protected String doInBackground(String... params) {
try {
// Enter URL address where your php file resides
url = new URL("http://etriplay.com/app/beacon_GetInform.php");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return "exception";
}
try {
// Setup HttpURLConnection class to send and receive data from php and mysql
conn = (HttpURLConnection)url.openConnection();
conn.setReadTimeout(READ_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
// setDoInput and setDoOutput method depict handling of both send and receive
conn.setDoInput(true);
conn.setDoOutput(true);
// JSON
JSONObject jsonObject = new JSONObject();
jsonObject.put("userid", "membe00001");
jsonObject.put("mail", "test#mail.com");
jsonObject.put("uuid", a);
Log.v("v", String.valueOf(jsonObject));
// Open connection for sending data
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(
new OutputStreamWriter(os, "UTF-8"));
writer.write(String.valueOf(jsonObject));
writer.flush();
writer.close();
os.close();
conn.connect();

In this case If you want object or something to put in json you can do ie by-:
try
{
jsonObject.put("value",chatMessage.getDate());
}
catch (JSONException e)
{
e.printStackTrace();
}
as in jsonobject.put("key",value);
You can assign the int value,string value,boolean value or whatever you want

Getting "Error parsing data org.json.JSONException: End of input at character 0 of" on reddit API

Hello I'm trying to use this endpoint www.reddit.com/reddits.json to show some list on android and I'm getting this error, below is my code.
I have this asynctask class on my main activity class:
private class AsyncListLoader extends AsyncTask<String, Integer, JSONObject>{
private JSONParser jsonParser = new JSONParser();
private static final String REDEEM_URL = "http://www.reddit.com/reddits.json";
private HashMap<String, String> param = new HashMap<>();
#Override
protected JSONObject doInBackground(String... params) {
JSONObject json = jsonParser.makeHttpRequest(REDEEM_URL, "GET", param);
if (json != null) {
Log.d("JSON result", json.toString());
return json;
}
else {
Log.d("JSON result", "is null");
}
return null;
}
#Override
protected void onPostExecute(JSONObject s) {
try {
if(!s.has("kind")){
Toast.makeText(MainActivity.this, "Something went wrong", Toast.LENGTH_LONG).show();
}
else {
JSONObject list = s.getJSONObject("data");
JSONArray childrens = list.getJSONArray("children");
for(int i = 0; i < childrens.length(); i++){
JSONObject o = childrens.getJSONObject(i).getJSONObject("data");
Feed f = new Feed(o.getString("icon_img"),o.getString("banner_img"),o.getString("display_name"));
MainActivity.this.adapter.add(f);
}
}
} catch (JSONException e){
e.printStackTrace();
}
}
}
makehttpRequest when get:
if(method.equals("GET")){
// request method is GET
if (sbParams.length() != 0) {
url += "?" + sbParams.toString();
}
try {
urlObj = new URL(url);
conn = (HttpURLConnection) urlObj.openConnection();
conn.setDoOutput(false);
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept-Charset", charset);
conn.setConnectTimeout(15000);
conn.connect();
} catch (IOException e) {
e.printStackTrace();
}
}
try {
//Receive the response from the server
InputStream in = new BufferedInputStream(conn.getInputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
Log.d("JSON Parser", "result: " + result.toString());
} catch (IOException e) {
e.printStackTrace();
}
conn.disconnect();
// try parse the string to a JSON object
try {
jObj = new JSONObject(result.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON Object
return jObj;
I tested out another json endpoints on the web and they are working. I dont have any idea why is this happening.
EDIT:
No param is being used so the url is fine.
The json is valid, I checked this in differents websites.

NullPointerException on HttpURLConnection in background thread

I'm trying to request a JSON resource. This code works fine, then if I call it a few more times, it throws a NullPointer exception on this line
InputStream in = new BufferedInputStream(conn.getInputStream());
Again this code seems to work fine a few times. But if it is called more than two or three times, it throws the error.
Any idea?
In this method
public JSONObject makeHttpRequest(String data) {
// request method is POST
try {
urlObj = new URL(someURLHere);
conn = (HttpURLConnection) urlObj.openConnection();
conn.setDoInput(true);
conn.setDoOutput(true);
conn.setUseCaches(false);
conn.setRequestMethod("POST");
conn.setRequestProperty("Accept-Charset", "UTF-8");
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Accept", "application/json");
//conn.setRequestProperty("Content-Length", "" + data.length());
conn.setFixedLengthStreamingMode(data.getBytes().length);
conn.setReadTimeout(10000);
conn.setConnectTimeout(15000);
conn.connect();
wr = new DataOutputStream(conn.getOutputStream());
wr.writeBytes(data);
wr.flush();
wr.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
//Receive the response from the server
InputStream in = new BufferedInputStream(conn.getInputStream());
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
conn.disconnect();
if (result != null) {
Log.d("JSON Parser", "Result string: " + result.toString());
// try parse the string to a JSON object
try {
jObj = new JSONObject(result.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
} else {
Log.d("JSON Parser", "Result string WAS NULL: ");
}
// return JSON Object
return jObj;
}
The null pointer exception.
JSONCommunicator.makeHttpRequest(JSONCommunicator.java:123)
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #4
java.lang.RuntimeException: An error occured while executing
doInBackground() at android.os.AsyncTask$3.done(AsyncTask.java:299)
at
java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
at
java.util.concurrent.FutureTask.setException(FutureTask.java:124)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
at java.util.concurrent.FutureTask.run(FutureTask.java:137) at
android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230) at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:856) Caused by:
java.lang.NullPointerException at
JSONCommunicator.makeHttpRequest(JSONCommunicator.java:141)
Here is the background method used to call the JSONCommunicator.
public class BGDownloadImageList extends AsyncTask<String, Void, Boolean> {
boolean hasResults = false;
#Override
protected void onPreExecute() {
}
#Override
protected Boolean doInBackground(String... params) {
String json = JSONCalls.getImagesJSON());
System.out.println("doInBackground: JSON: " + json);
JSONCommunicator jsonCommunicator = new JSONCommunicator();
if(jsonCommunicator != null) {
JSONObject result = jsonCommunicator.makeHttpRequest(json); //NOTICE THIS IS AN IMAGE REQUEST
System.out.println("doInBackground: result: " + result);
JSONObject dictTowx, dictData;
try {
dictTowx = result.getJSONObject("towXResponse");
dictData = dictTowx.getJSONObject("Data");
if (dictData != null) {
System.out.println("IMAGES " + dictData);
if (dictData.has("Message")) {
if (dictData.getString("Message").equals("no images")) {
System.out.println("NO IMAGES");
}
} else {
hasResults = true;
addImagesToArray(dictData);
}
}
} catch (JSONException e) {
System.out.println("doInBackground: JSON ERROR");
e.printStackTrace();
}
} else {
System.out.println("doInBackground: jsonCommunicator NULL");
}
return hasResults; //passed to OnPostExecute
}
#Override
protected void onPostExecute(Boolean r) {
////...
}
}

android Error converting result java.io.FileNotFoundException

I have created an API in post method which is working fine in postman i.e it is giving desired response. But while using that API in Android it is giving error:
Error converting result java.io.FileNotFoundException and Error parsing data org.json.JSONException: End of input at character 0 of
I would appreciate anyone guiding me on how to do this.
Here is the code of makeHttpRequest method of jsonparser:
public JSONObject makeHttpRequest2(String url2 , String method,
String name, String password) throws IOException {
// Making HTTP request
try {
// check for request method
if (method == "POST") {
// request method is POST
url = new URL(url2);
conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setUseCaches(false);
conn.setConnectTimeout(10000);
conn.setReadTimeout(10000);
conn.setRequestProperty("Content-Type", "application/json");
conn.setRequestProperty("Host", "android.schoolportal.gr");
conn.connect();
JSONObject jsonParam = new JSONObject();
jsonParam.put("name", name);
//jsonParam.put("email", email);
jsonParam.put("password", password);
Log.d("json",String.valueOf(jsonParam));
OutputStreamWriter out=new OutputStreamWriter(
conn.getOutputStream());
out.write(jsonParam.toString());
out.close();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
try {
InputStream is = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "UTF-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
Log.e("JSON", json);
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
Log.d("json3",String.valueOf(json));
// return JSON String
return jObj;
}

First off you are not checking that the request was successful, before calling the conn.getInputStream(); If the request failed that stream is empty and you need to call
new BufferedReader(new InputStreamReader(connection.getErrorStream()));
What line number is giving you issue? If you print out the JSON to insure that the response is valid JSON.

Add this to your code:
conn.setDoInput(true); //After or before of setDoOutput(true) for organization :)
conn.setChunkedStreamingMode(0);
conn.setRequestProperty("Content-Type", "application/json; charset=utf-8");
EDIT :
And this if you need to upload a JSON for the server:
conn.setRequestProperty("Content-Length", "" + Integer.toString(JsonObjectstr.getBytes().length)); // Get the json string length