Java tutorial
/* * Copyright 2013 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.networkbasic; import android.content.Context; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.Bundle; import android.support.v4.app.FragmentActivity; import android.util.TypedValue; import android.view.Menu; import android.view.MenuItem; import com.example.android.common.SimpleTextFragment; import com.example.android.common.logger.Log; import com.example.android.common.logger.LogWrapper; import com.example.android.common.logger.MessageOnlyLogFilter; /** * Sample application demonstrating how to test whether a device is connected, * and if so, whether the connection happens to be wifi or mobile (it could be * something else). * * This sample uses the logging framework to display log output in the log * fragment (LogFragment). */ public class MainActivity extends FragmentActivity { public static final String TAG = "Basic Network Demo"; // Whether there is a Wi-Fi connection. private static boolean wifiConnected = false; // Whether there is a mobile connection. private static boolean mobileConnected = false; // Reference to the fragment showing events, so we can clear it with a button // as necessary. private LogFragment mLogFragment; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Initialize text fragment that displays intro text. SimpleTextFragment introFragment = (SimpleTextFragment) getSupportFragmentManager() .findFragmentById(R.id.intro_fragment); introFragment.setText(R.string.intro_message); introFragment.getTextView().setTextSize(TypedValue.COMPLEX_UNIT_DIP, 16.0f); // Initialize the logging framework. initializeLogging(); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { // When the user clicks TEST, display the connection status. case R.id.test_action: checkNetworkConnection(); return true; // Clear the log view fragment. case R.id.clear_action: mLogFragment.getLogView().setText(""); return true; } return false; } /** * Check whether the device is connected, and if so, whether the connection * is wifi or mobile (it could be something else). */ private void checkNetworkConnection() { ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo activeInfo = connMgr.getActiveNetworkInfo(); if (activeInfo != null && activeInfo.isConnected()) { wifiConnected = activeInfo.getType() == ConnectivityManager.TYPE_WIFI; mobileConnected = activeInfo.getType() == ConnectivityManager.TYPE_MOBILE; if (wifiConnected) { Log.i(TAG, getString(R.string.wifi_connection)); } else if (mobileConnected) { Log.i(TAG, getString(R.string.mobile_connection)); } } else { Log.i(TAG, getString(R.string.no_wifi_or_mobile)); } } /** Create a chain of targets that will receive log data */ public void initializeLogging() { // Using Log, front-end to the logging chain, emulates // android.util.log method signatures. // Wraps Android's native log framework LogWrapper logWrapper = new LogWrapper(); Log.setLogNode(logWrapper); // A filter that strips out everything except the message text. MessageOnlyLogFilter msgFilter = new MessageOnlyLogFilter(); logWrapper.setNext(msgFilter); // On screen logging via a fragment with a TextView. mLogFragment = (LogFragment) getSupportFragmentManager().findFragmentById(R.id.log_fragment); msgFilter.setNext(mLogFragment.getLogView()); } }