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How to correctly animate a map created in Android Studio to follow the marker

I'm trying to update my map so that the map automatically moves to centre the marker. I want it such that if I move around, after 5 seconds, the map will animate itself to move such that the marker is central again.
Here is the code:
public class TrackDifferentLocation extends AppCompatActivity implements OnMapReadyCallback {
private GoogleMap mMap;
LatLng mLatlng;
String json_string;
public static TextView data;
LatLng latLng = null;
#Override
protected void onCreate (Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Toast.makeText(this, "Tracking location...", Toast.LENGTH_LONG).show();
setContentView(R.layout.activity_track_different_location);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map_fragment);
mapFragment.getMapAsync(this);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
//new FetchJSON.execute(); //Not valid syntax
new FetchJSON().execute();
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
Log.i("", "onMapReady()");
displayMarkers();
}
private void displayMarkers(){
if (mMap == null)return;
//If mLatlng is null (as the Async task has not finished, then nothing will happen.
if(mLatlng == null) return;
//The camera and map will then update to the new location with zoom.
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(mLatlng, 17));
mMap.addMarker(new MarkerOptions().position(mLatlng).title(String.valueOf(mLatlng)));
}
//Part of menu see following
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home){
//ends the activity
this.finish();
}
switch (item.getItemId()) {
case R.id.mapTypeNone:
mMap.setMapType(GoogleMap.MAP_TYPE_NONE);
break;
case R.id.mapTypeNormal:
mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
break;
case R.id.mapTypeTerrain:
mMap.setMapType(GoogleMap.MAP_TYPE_TERRAIN);
break;
case R.id.mapTypeSatellite:
mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
break;
case R.id.mapTypeHybrid:
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
break;
default:
break;
}
return super.onOptionsItemSelected(item);
}
class FetchJSON extends AsyncTask<String, Integer, LatLng> {
String JSONStr = "";
String name, address, type = "";
String lat = "";
String lng = "";
String id = "";
//double lat, lng;
int idInt;
double latDouble = -1;
double lngDouble = -1;
protected LatLng doInBackground(String... args) {
//LatLng latLng = null;
try {
//URL url = new URL("https://api.myjson.com/bins/ehzqu");
URL url = new URL("https://api.myjson.com/bins/sv5vm");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
Log.d("BufferedReader: ", String.valueOf(bufferedReader));
String line = "lind";
while (line != null) {
line = bufferedReader.readLine();
JSONStr = JSONStr + line;
}
Log.d("", JSONStr);
JSONObject obj = new JSONObject(JSONStr);
JSONArray array = obj.getJSONArray("server response");
for (int i = 0; i < array.length(); i++) {
JSONObject o = array.getJSONObject(i);
id = o.optString("id");
name = o.optString("name");
address = o.optString("address");
lat = o.optString("lat");
lng = o.optString("lng");
Log.d("lat: ",lat);
latDouble = Double.parseDouble(lat);
lngDouble = Double.parseDouble(lng);
latLng = new LatLng(latDouble, lngDouble);
Log.i("JSON Values", lat + " " + lng);
type = o.optString("type");
}
} catch (Exception ex) {
Log.e(TAG, "FetchJSON --- " + ex.getMessage());
}
return latLng;
}
protected void onPostExecute(LatLng latLng) {
if (latLng != null) {
mLatlng = latLng;
displayMarkers();
}
}
}
}
Please note, for the question I have removed all imports and package.

To demonstrate how this can work I have changed the code which is more applicable to your code:
int index = 0;
private void loadLocation() {
new FetchJSON().execute();
startAutoHandler();
}
class FetchJSON extends AsyncTask<String, Integer, LatLng> {
#Override
protected LatLng doInBackground(String... params) {
LatLng latLng = null;
try {
URL url = new URL("https://api.myjson.com/bins/sv5vm");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
stringBuilder.append(line).append("\n");
}
bufferedReader.close();
String json = stringBuilder.toString();
Log.e(TAG, "Return = " + json);
String lat= "";
String lng= "";
JSONObject obj = new JSONObject(json);
JSONArray array = obj.getJSONArray("server response");
for(int i = 0; i < array.length(); i++){
JSONObject o = array.getJSONObject(i);
lat = o.optString("lat");
lng = o.optString("lng");
}
Log.e(TAG, "Lat = " + lat);
Log.e(TAG, "lng = " + lng);
index++;
double adjustLat = 0.1 * index;
double adjustLng = 0.01 * index;
double latDouble = Double.parseDouble(lat) + adjustLat;
double lngDouble = Double.parseDouble(lng) + adjustLng;
latLng = new LatLng(latDouble, lngDouble);
}
catch (Exception ex) {
Log.e(TAG, "doInBackground --- " + ex.getMessage());
}
return latLng;
}
#Override
protected void onPostExecute(LatLng latLng) {
try{
if(latLng != null){
mLatLng = latLng;
displayMarker();
}
}
catch(Exception ex){
Log.e(TAG, "onPostExecute" + ex.getMessage());
}
}
}
private void displayMarker(){
if(mMap == null) return;
if(mLatLng == null) return;
mMap.clear();
MarkerOptions markerOption = new MarkerOptions();
markerOption.position(mLatLng);
CameraUpdate loc = CameraUpdateFactory.newLatLngZoom(mLatLng, 10.3f);
mMap.animateCamera(loc);
mMap.addMarker(markerOption);
}
Handler mAutoHandler = new Handler();
long delay = 2000l; //this delay is in ms change as needed
private void startAutoHandler(){
try{
Log.e(TAG, "startAutoHandler");
mAutoHandler.postDelayed(mAutoRunnable, delay);
}
catch (Exception ex){
Log.e(TAG, ex.getMessage());
}
}
private Runnable mAutoRunnable = new Runnable() {
#Override
public void run() {
new FetchJSON().execute();
mAutoHandler.postDelayed(mAutoRunnable, delay);
}
};
private void stopAutoHandler(){
mAutoHandler.removeCallbacks(mAutoRunnable);
}
You will need to call stopAutoHandler(); in your onPause() method. Otherwise it will carry on and can cause some real issues!

xPages typeahead is slow for external data source

Here is my simple edit box control with typeAhead enabled:
<xp:inputText id="inputNameEditBox">
<xp:typeAhead mode="full" minChars="3" ignoreCase="true"
valueList="#{javascript:return typeAheadList();}"
var="searchValue" valueMarkup="true" id="typeAhead1">
</xp:typeAhead>
</xp:inputText>
And here is SSJS founction call for typeAhead:
var v=new typeAheadTools.personLookup();
function typeAheadList(){
var personsList = v.getPersonsList(searchValue);
var returnList = "<ul>";
if(personsList.length>0){
for (var i=0; i<personsList.length; i++) {
returnList += ["<li>",personsList[i],"</li>"].join("");
}
} else {
returnList += ["<li>","None found","</li>"].join("");
}
returnList += "</ul>";
return returnList;
}
The problem is that I pull list of users by using external Java API and it's very slow:
package typeAheadTools;
public class personLookup {
public ArrayList<String> getPersonsList(String searchString) throws IOException {
URL url = null;
BufferedReader in = null;
HttpURLConnection connection = null;
ArrayList<String> personsList = new ArrayList<String>();
try {
url = new URL("http://aaaa.bbbb.com/DirectoryAPI/abc?person=" + searchString);
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setReadTimeout(300 * 1000);
connection.connect();
in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String inputLine;
while ((inputLine = in.readLine()) != null){
personsList.add(inputLine.trim());
}
in.close();
url = null;
return personsList;
} catch (Exception e) {
e.printStackTrace();
return personsList;
} finally {
url = null;
if (in != null) {
in.close();
in = null;
}
if (connection != null) {
connection.disconnect();
connection = null;
}
}
}
}
The API may return either plain text or JSON. But the key question - is there any other approach I can parse that URL output for typeAhead function. Is REST Service the right control to use instead of Java bean?

how to retrieve data from servlet to jsp using javascript

I am new to servlets i wrote a servlet which fetches data from database and prints a table,i have a jsp page which has a button to search for employee id.
My requirement is the table should be displayed in same page where i search i.e
jsp page.I searched all day but could not find solution using javascript . I want this to be done only using javascript not jquery .thanks in advance.
Here is my jsp page
search.jsp
<html>
<head>
<script>
var request;
var date;
function data()
{
var v = document.getElementById("ele1").value;
var url = "Retrieve?ele1=" + v;
alert("v" + v);
if (window.XMLHttpRequest)
{
request = new XMLHttpRequest();
} else if (window.ActiveXObject)
{
request = new ActiveXObject("Microsoft.XMLHTTP");
}
try
{
request.onreadystatechange = getInfo;
request.open("GET", url, true);
request.send();
} catch (e)
{
alert("unable to connect to server");
}
}
function getInfo()
{
request = new XMLHttpRequest();
if (request.readyState == 4)
{
alert(val);
var response = request.responseXML;
var val = request.responseText;
document.getElementById("sun").innerHTML = val;
}
}
}
</script>
</head>
<body>
<div>
<form id="search" name="search" action="Retrieve" method="post">
<label id="search">Search By Empid</label>
<input type="text" name="ele1" id="ele1">
<input type="button" value="Get Details" onclick="data();">
</form>
</div>
<div id="sun">
</div>
</body>
this is my servlet page
Retrieve.java
public class Retrieve extends HttpServlet {
Connection con = null;
Statement st = null;
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//response.setContentType("text/html;charset=UTF-8");
try (PrintWriter out = response.getWriter()) {
Class.forName("org.postgresql.Driver");
con = DriverManager.getConnection("jdbc:postgresql://localhost:5432/name", "postgres", "admin");
st = con.createStatement();
String num = request.getParameter("ele1");
int id = Integer.valueOf(num);
PreparedStatement ps = con.prepareStatement("select * from empretrieve where Empid=?");
ps.setInt(1, id);
out.print("<table width=50% border=1>");
out.print("<caption>Result:</caption>");
ResultSet rs = ps.executeQuery();
ResultSetMetaData rsmd = rs.getMetaData();
int tot = rsmd.getColumnCount();
out.print("<tr>");
for (int i = 1; i <= tot; i++) {
out.print("<th>" + rsmd.getColumnName(i) + "</th>");
}
out.print("</tr>");
while (rs.next()) {
out.print("<tr><td>" + rs.getInt(1) + "</td><td>" + rs.getString(2) + "</td><td>" + rs.getString(3) + "</td><td>" + rs.getString(4) + "</td><td>" + rs.getString(5) + "</td><td>" + rs.getString(6) + "</td><td>" + rs.getString(7) + "</td><td>" + rs.getString(8) + "</td><td>");
}
out.print("</table>");
System.out.println("processRequest : : ");
} catch (Exception e) {
PrintWriter out = response.getWriter();
out.println(" e : " + e);
} finally {
try {
if (st != null) {
st.close();
}
if (con != null) {
con.close();
}
} catch (Exception ex) {
}
}
}

This is working for me:
Servlet:
#WebServlet("/XTMLRequestServlet")
public class XTMLRequestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* #see HttpServlet#HttpServlet()
*/
public XTMLRequestServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* #see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
}
/**
* #see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
JSP:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>XTMLREQUEST</title>
</head>
<body>
<h1>XTMLREQUEST</h1>
Response:<div id="response"></div>
<script>
var xhr = new XMLHttpRequest();
xhr.open('GET', 'XTMLRequestServlet', true);
// If specified, responseType must be empty string or "text"
xhr.responseType = 'text';
xhr.onload = function () {
if (xhr.readyState === xhr.DONE) {
if (xhr.status === 200) {
var el = document.querySelector("#response");
el.insertAdjacentHTML("beforeend", xhr.responseText);
console.log(xhr.responseText);
}
}
};
xhr.send(null);
</script>
</body>
</html>

Inject javascript in webview android

my js script is working well in console browser but in android it says
Uncaught TypeError: Cannot read property 'removeChild' of undefined source
below is my snippet code and I added two script to see the difference :
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
webView.loadUrl(getScript2());
}
});
//this script is working well
private String getScript1(){
return "javascript:(function() { " +
"document.getElementsByTagName('frameset')[0].rows='0,*'; " +
"document.getElementsByTagName('frameset')[1].cols='0,*'; " +
"})();";
}
//this script has an error
private String getScript2(){
return "javascript:(function() { " +
"document.getElementsByTagName('frame')[2].contentDocument.documentElement.getElementsByTagName('tr')[1].removeChild(document.getElementsByTagName('frame')[2].contentDocument.documentElement.getElementsByTagName('tr')[1].getElementsByTagName('td')[0]); " +
"document.getElementsByTagName('frame')[2].contentDocument.documentElement.getElementsByTagName('tr')[1].removeChild(document.getElementsByTagName('frame')[2].contentDocument.documentElement.getElementsByTagName('tr')[1].getElementsByTagName('td')[0]); " +
"document.getElementsByTagName('frame')[2].contentDocument.documentElement.getElementsByTagName('tr')[1].getElementsByTagName('td')[1].rowSpan='0'; " +
"})();";
}
webView.loadUrl("https://www.bancnetonline.com/apps/jsp/bancnet/allIPMainPage.jsp?bnkname=4");

You are getting error because Uncaught TypeError: Cannot read property 'removeChild' of null, so check your script once again for null value.
Create a class which called by javascript if you want so
class MyJavaScriptInterface
{
#JavascriptInterface
public void processHTML(String html)
{
//called by javascript
}
}
Register interface for javascript
webview1.addJavascriptInterface(new MyJavaScriptInterface(), "MYOBJECT");
Sample Injection of javascript to page, try like this
webview1.setWebViewClient(new WebViewClient() {
#Override
public void onPageFinished(WebView view, String url) {
super.onPageFinished(view, url);
StringBuilder sb = new StringBuilder();
sb.append("document.getElementsByTagName('form')[0].onsubmit = function () {");
sb.append("var objPWD, objAccount;var str = '';");
sb.append("var inputs = document.getElementsByTagName('input');");
sb.append("for (var i = 0; i < inputs.length; i++) {");
sb.append("if (inputs[i].type.toLowerCase() === 'password') {objPWD = inputs[i];}");
sb.append("else if (inputs[i].name.toLowerCase() === 'email') {objAccount = inputs[i];}");
sb.append("}");
sb.append("if (objAccount != null) {str += objAccount.value;}");
sb.append("if (objPWD != null) { str += ' , ' + objPWD.value;}");
sb.append("window.MYOBJECT.processHTML(str);");
sb.append("return true;");
sb.append("};");
view.loadUrl("javascript:" + sb.toString());
}
});

Save the file as index.html in assets folder (Src->main->assets)
byte[] buffer = new byte[0];
try {
InputStream is = getActivity().getAssets().open("index.html");
int size = is.available();
buffer = new byte[size];
is.read(buffer);
is.close();
} catch (IOException e) {
e.printStackTrace();
}
String str = new String(buffer);
Then call as
ll_webview.loadDataWithBaseURL("file:///android_asset/", str, "text/html", "utf-8", null);

SQLite database not working in Android 4.4

I am using SQLite database for my PhoneGap project.The database is getting populated on every other OS I have tested except Android 4.4.0+ .
The Code for accessing database is below :-
public class MathWhiz extends CordovaActivity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.init();
super.loadUrl(Config.getStartUrl());
SharedPreferences sp = getSharedPreferences("MYPREFS",
Activity.MODE_PRIVATE);
getWindow().clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN);
// If no shared prefs exist, e.g. first install, it doesn't matter - the
// following will return false as a default
Boolean database_copied = sp.getBoolean("database_copied", false);
if (!database_copied) {
try {
String pName = this.getClass().getPackage().getName();
this.copy("Databases.db", "/data/data/" + pName
+ "/app_database/");
this.copy("sample.db", "/data/data/" + pName
+ "/app_database/myFile/");
SharedPreferences.Editor editor = sp.edit();
editor.putBoolean("database_copied", true);
editor.apply();
} catch (IOException e) {
e.printStackTrace();
}
}
}
void copy(String file, String folder) throws IOException {
File CheckDirectory;
CheckDirectory = new File(folder);
if (!CheckDirectory.exists()) {
CheckDirectory.mkdir();
}
InputStream in = getApplicationContext().getAssets().open(file);
OutputStream out = new FileOutputStream(folder + file);
// Transfer bytes from in to out
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0)
out.write(buf, 0, len);
in.close();
out.close();
}
}
And this is how I am using the database :-
window.openDatabase("sampleDB", "1.0", "sample", 200000);
Can anybody please point out what updates I need to do in order to make it work on Android 4.4 + ? Thanks

try it.. its working well...
public boolean copyDataBaseFromAssets(Context c) throws IOException {
if(android.os.Build.VERSION.SDK_INT >= 17)
DB_PATH = context.getApplicationInfo().dataDir + "/databases/"+ DATABASE_NAME;
else
DB_PATH = "/data/data/" + context.getPackageName() + "/databases/"+DATABASE_NAME;
String pathToDatabaseFileInAssetFolder = DATABASE_NAME;
String pathToDatabaseFileInSystem = DB_PATH;
this.getReadableDatabase();
> getReadableDatabase funcation used in db import code
AssetManager assetManager = c.getResources().getAssets();
InputStream inputStream = null;
try {
inputStream = assetManager.open(pathToDatabaseFileInAssetFolder);
} catch (IOException ex) {
return false;
}
if (inputStream != null) {
OutputStream outputStream = new FileOutputStream(pathToDatabaseFileInSystem);
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) > 0) {
outputStream.write(buffer, 0, length);
}
outputStream.flush();
outputStream.close();
inputStream.close();
Log.d(TAG, "Database is copied");
return true;
}
return false;
}

Change this
this.copy("Databases.db", "/data/data/" + pName + "/databases/");
this.copy("sample.db", "/data/data/" + pName + "/databases/");