I would like to put a Network Detector in an Android application, to inform a Screen immediately the Network state even if that state is changing. I have study similar questions in:
Android: Internet connectivity change listener
So my Java code in Main Activity is:
package com.example.netdetector;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkInfo;
import android.net.NetworkRequest;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.*;
public class MainActivity extends AppCompatActivity {
private TextView Screen;
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Screen = (TextView) findViewById(R.id.Screen);
Screen.setText("Start!");
ConnectivityManager.NetworkCallback networkCallback = new ConnectivityManager.NetworkCallback() {
#Override
public void onAvailable(Network network) {
// network available
Screen.setText("Net On!");
}
#Override
public void onLost(Network network) {
// network unavailable
Screen.setText("Net Off!");
}
};
ConnectivityManager connectivityManager =
(ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
connectivityManager.registerDefaultNetworkCallback(networkCallback);
} else {
NetworkRequest request = new NetworkRequest.Builder()
.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET).build();
connectivityManager.registerNetworkCallback(request, networkCallback);
}
}
}
The AndroidManifest.xml is:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.netdetector">
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.NetDetector">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
The Layout activity_main.xml is:
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="#+id/Screen"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="Hello World!"
android:textSize="25sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintHorizontal_bias="0.5"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.222" />
</androidx.constraintlayout.widget.ConstraintLayout>
There are some issues:
Starting the App with the Network Off, the Screen displays "Start!" instead of "Net Off!"
Starting the App with the Network On, the Screen displays "Net On" that is fine
On changing Internet state while the app is running the Screen displays the right text for a few moments and the app closes immediately.
How can I fix 1 and 3? What went wrong?
Thanks
Nickolas
I have been researching everywhere and haven't found a concrete example of how to do this. I want to know how to send a HTTP request to Google to bring back data on places around my current location which is stored in LatLng? and then parse that data in JSON to then display on my map. Im new to android development so apologies if this question seems silly. I have looked through the Google documentation on this but I cant get my head around it :(
My MainActivity.Java file:
package com.example.mapapp;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMyLocationChangeListener;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.LatLng;
public class MainActivity extends FragmentActivity implements OnMyLocationChangeListener {
GoogleMap map;
LatLng myPosition;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();
map.setMyLocationEnabled(true);
LocationManager locationmanager = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationmanager.getBestProvider(criteria, true);
Location location = locationmanager.getLastKnownLocation(provider);
if(location!=null){
double latitude = location.getLatitude();
double longitude = location.getLongitude();
myPosition = new LatLng(latitude, longitude);
}
}
#Override
public void onMyLocationChange(Location location) {
// TODO Auto-generated method stub
}
}
My Manifest.xml file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.mapapp"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="21" />
<permission
android:protectionLevel="signature"
android:name="com.example.mapapp.permission.MAPS_RECEIVE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-feature android:required="true" android:glEsVersion="0x00020000"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<uses-library
android:name="com.google.android.maps"/>
<activity
android:name=".MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="MY_API_KEY"/>
</application>
</manifest>
My Layout.xml file:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.example.mapapp.MainActivity" >
<ListView
android:id="#+id/list"
android:layout_width="fill_parent"
android:layout_height="250dp"
/>
<fragment
android:id="#+id/map"
android:name="com.google.android.gms.maps.MapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</RelativeLayout>
If you want to show places nearby, you need to use Google Places API.
You can read this tutorial about how to setup API project in your Google Developer Console.
Also, you can read this series of tutorials about how to to show places nearby.
It give error that unfortunately map testing has stopped I have add all permissions and
put correct value of key......
This is main activity Java file.
package com.vogella.android.locationapi.maps;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
public class MainActivity extends Activity {
static final LatLng HAMBURG = new LatLng(53.558, 9.927);
static final LatLng KIEL = new LatLng(53.551, 9.993);
private GoogleMap map;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.maptesting)).getMap();
Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG).title("Hamburg"));
Marker kiel = map.addMarker(new MarkerOptions().position(KIEL).title("Kiel")
.snippet("Kiel is cool").icon(BitmapDescriptorFactory
.fromResource(R.drawable.ic_launcher)));
Move the camera instantly to hamburg with a zoom of 15.
map.moveCamera(CameraUpdateFactory.newLatLngZoom(HAMBURG, 15));
Zoom in, animating the camera.
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
}
onCreateOptionsMenu:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
This is XML file..
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<fragment
android:id="#+id/maptesting"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.MapFragment" />
</RelativeLayout>
this is manifest..
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.vogella.android.locationapi.maps"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="16"
android:targetSdkVersion="18" />
<permission
android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<uses-permission
android:name="com.vogella.android.locationapi.maps.permission. MAPS_RECEIVE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="com.google. android.providers. gsf.permission.
READ_GSERVICES" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.vogella.android.locationapi.maps.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="Key Value" />
<application>
</manifest>
Add this tag to your Manifest.xml file:
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version"/>
I am learning Android development with Lynda video tutorials.
I am using the Google map API v2, to display a map. I have done all the steps according to the tutorial.
when i try to view the application in my device, the application loads I can see the Google logo but map is not visible. (i see the white background with Google logo at the bottom).
I have added my code and the screenshot. can someone please help me to fix this. thank you..
Screenshot
My java code..
package lk.adspace.jaffnatemples;
import java.io.IOException;
import java.util.List;
import android.app.Dialog;
import android.location.Address;
import android.location.Geocoder;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
public class MainActivity extends FragmentActivity {
private static final int GPS_ERRORDIALOG_REQUEST = 9001;
GoogleMap mMap;
#SuppressWarnings("unused")
private static final double SEATTLE_LAT = 47.60621,
SEATTLE_LNG =-122.33207,
SYDNEY_LAT = -33.867487,
SYDNEY_LNG = 151.20699,
NEWYORK_LAT = 40.714353,
NEWYORK_LNG = -74.005973;
private static final float DEFAULTZOOM = 15;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (servicesOK()) {
setContentView(R.layout.activity_map);
if (initMap()) {
Toast.makeText(this, "Ready to map!", Toast.LENGTH_SHORT).show();
gotoLocation(SEATTLE_LAT, SEATTLE_LNG, DEFAULTZOOM);
}
else {
Toast.makeText(this, "Map not available!", Toast.LENGTH_SHORT).show();
}
}
else {
setContentView(R.layout.activity_main);
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public boolean servicesOK() {
int isAvailable = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (isAvailable == ConnectionResult.SUCCESS) {
return true;
}
else if (GooglePlayServicesUtil.isUserRecoverableError(isAvailable)) {
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(isAvailable, this, GPS_ERRORDIALOG_REQUEST);
dialog.show();
}
else {
Toast.makeText(this, "Can't connect to Google Play services", Toast.LENGTH_SHORT).show();
}
return false;
}
private boolean initMap() {
if (mMap == null) {
SupportMapFragment mapFrag =
(SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mMap = mapFrag.getMap();
}
return (mMap != null);
}
private void gotoLocation(double lat, double lng,
float zoom) {
LatLng ll = new LatLng(lat, lng);
CameraUpdate update = CameraUpdateFactory.newLatLngZoom(ll, zoom);
mMap.moveCamera(update);
}
public void geoLocate(View v) throws IOException {
hideSoftKeyboard(v);
EditText et = (EditText) findViewById(R.id.editText1);
String location = et.getText().toString();
Geocoder gc = new Geocoder(this);
List<Address> list = gc.getFromLocationName(location, 1);
Address add = list.get(0);
String locality = add.getLocality();
Toast.makeText(this, locality, Toast.LENGTH_LONG).show();
double lat = add.getLatitude();
double lng = add.getLongitude();
gotoLocation(lat, lng, DEFAULTZOOM);
}
private void hideSoftKeyboard(View v) {
InputMethodManager imm = (InputMethodManager)getSystemService(INPUT_METHOD_SERVICE);
imm.hideSoftInputFromWindow(v.getWindowToken(), 0);
}
}
My xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left|center_vertical"
android:text="Location:"
android:textSize="20sp" />
<EditText
android:id="#+id/editText1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center|center_vertical"
android:ems="10" >
<requestFocus />
</EditText>
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="right|center_vertical"
android:text="Go"
android:onClick="geoLocate"/>
</LinearLayout>
<fragment
android:id="#+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="292dp"
android:layout_height="374dp" />
</LinearLayout>
my Manifest file.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="lk.adspace.jaffnatemples"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<permission
android:name="lk.adspace.jaffnatemples.permission.MAPS_RECEIVE"
android:protectionLevel="signature"/>
<uses-permission android:name="lk.adspace.jaffnatemples.permission.MAPS_RECEIVE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission
android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
<uses-feature
android:glEsVersion="0x00020000"
android:required="true"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="lk.adspace.jaffnatemples.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="I Added my Api Key"/>
</application>
</manifest>
can someone please help me to fix this. Thank you.
updated manifest use this
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="lk.adspace.jaffnatemples"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />
<permission
android:name="lk.adspace.jaffnatemples.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
<uses-permission android:name="com.ram.googlemapsv2.permission.MAPS_RECEIVE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-feature
android:glEsVersion="0x00020000"
android:required="true" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="lk.adspace.jaffnatemples.MainActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.google.android.gms.version"
android:value="v3" />
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="your api key" />
</application>
</manifest>
You can only view it in a phone.
What you see now is all you can get in the Emulator.
You're not asking for any of the gps permissions.
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
Also since you're using fake locations, you might want to include this one as well. I don't know if it's relevant in this case, but just in case.
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"/>
Also, I know you said you're currently testing on a device, but for anyone who's curious about running google maps on an emulator (with the new Google Play dependency), it can be done this way.
Did you generate the API-Key with your debug-keystore or do you sign the application with a another keystore to build for the device? The API-Key is bind to a keystore and must be changed if you sign with another keystore or another debug-keystore on another developer-machine.
seems the guy who wrote about the permissions was right,
but I had the same problem and the solution was to correct the package name in the
internet site of google where you get the api key.
because I built at the same day another project with almost the same package name,
and forgot I produced the api key with that project,it didn't work for me with the second project.
I have an application with AdMob advertisement. I have created an account and have an application_id. It is all right, the application sends requests for server, server fixes it. But the application doesn't show me a banner. My code:
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/linear"
android:orientation="vertical" >
</LinearLayout>
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.nda.ad"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="7" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:label="#string/app_name"
android:name=".AdmobActivity" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name="com.google.ads.AdActivity"
android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/>
</application>
</manifest>
And code of my activity:
package com.nda.ad;
import com.google.ads.AdRequest;
import com.google.ads.AdSize;
import com.google.ads.AdView;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
public class AdmobActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LinearLayout layout = (LinearLayout)findViewById(R.id.linear);
// Create the adView
// Please replace MY_BANNER_UNIT_ID with your AdMob Publisher ID
AdView adView = new AdView(this, AdSize.BANNER, "a14eb6c98335a35");
// Add the adView to it
layout.addView(adView);
// Initiate a generic request to load it with an ad
AdRequest request = new AdRequest();
request.setTesting(true);
adView.loadAd(request);
}
}
Where have I made a mistake?