네트워크 상태 확인
단말의 인터넷 연결 상태는 어떻게 알 수 있을까?
인터넷에 연결되어 있다면 일반망에 연결되어 있는지, 무선랜(WiFi)에 연결 되었는지 어떻게 확인할까?
인터넷의 연결 상태에 따라 사용자에게 보여줄 결과물을 다르게 만들고 싶은 경우가 있다.
예제를 통해 알아보자.
예제
MainActivity.java
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package org.techtown.network;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
TextView textView;
WiFiReceiver wifiReceiver;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = findViewById(R.id.textView);
Button button = findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
checkConnectivity();
}
});
wifiReceiver = new WiFiReceiver();
}
public void checkConnectivity() {
ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info = manager.getActiveNetworkInfo();
if (info != null) {
if (info.getType() == ConnectivityManager.TYPE_WIFI) {
println("WiFi로 설정됨");
} else if (info.getType() == ConnectivityManager.TYPE_MOBILE) {
println("일반망으로 설정됨");
}
println("연결 여부 : " + info.isConnected());
} else {
println("데이터통신 불가");
}
}
public void println(String data) {
textView.append(data + "\n");
}
@Override
protected void onPause() {
super.onPause();
unregisterReceiver(wifiReceiver);
}
@Override
protected void onResume() {
super.onResume();
IntentFilter filter = new IntentFilter(); // 코드에서 수신자 등록하기
filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
registerReceiver(wifiReceiver, filter);
}
class WiFiReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(WifiManager.WIFI_STATE_CHANGED_ACTION)) { // WiFi 상태 체크하기
int state = intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE, -1);
if (state == WifiManager.WIFI_STATE_ENABLED) {
println("WiFi enabled");
} else if (state == WifiManager.WIFI_STATE_DISABLED) {
println("WiFi disabled");
}
} else if (action.equals(WifiManager.NETWORK_STATE_CHANGED_ACTION)) {
NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
WifiManager manager = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
String ssid = manager.getConnectionInfo().getSSID();
if (info.getState() == NetworkInfo.State.CONNECTED) {
println("Connected : " + ssid);
} else if (info.getState() == NetworkInfo.State.DISCONNECTED) {
println("Disconnected : " + ssid);
}
}
}
}
}
https://www.acmicpc.net/problem/17215
권한 추가
AndroidManifest.xml
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<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
결과
