I am creating an Android application. Here I need to get the IP address of the Android device. Below is my MainActivity code,
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.format.Formatter;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.ByteOrder;
public class MainActivity extends AppCompatActivity {
Button button;
TextView txtView;
public static Context context = MyApplication.getAppContext();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerOnButton();
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
public void addListenerOnButton() {
button = (Button) findViewById(R.id.button_ip);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
int ipAddress = wifiInfo.getIpAddress();
if (ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN)) {
ipAddress = Integer.reverseBytes(ipAddress);
}
byte[] ipByteArray = BigInteger.valueOf(ipAddress).toByteArray();
String ipAddressString;
try {
ipAddressString = InetAddress.getByAddress(ipByteArray)
.getHostAddress();
} catch (UnknownHostException ex) {
Log.e("WI-Resource", "Unable to get host address.");
ipAddressString = null;
}
System.out.println(ipAddress);
//txtView.setText(ipAddress);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
After creating the WiFi hotspot in my device, I started the application, then it gives following exception,
Unable to get host address
So please anyone can help me to solve this problem?
