Android Open Source - android-http Connectivity Helper

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License

The source code is released under:
Apache License
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Java Source Code

/*
 * Copyright (C) 2012, 2013 the diamond:dogs|group
 *//from   w w  w.ja v  a  2 s  . c o  m
 * 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 at.diamonddogs.util;

import java.net.InetAddress;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import android.content.Context;
import android.content.pm.PackageManager;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import at.diamonddogs.data.dataobjects.WebRequest;

/**
 * A helper class that allows programmers to verify connectivity according to
 * {@link WebRequest} defined rules
 */
public class ConnectivityHelper {

  private static final Logger LOGGER = LoggerFactory.getLogger(ConnectivityHelper.class.getSimpleName());

  /**
   * An instance of {@link ConnectivityManager} used to check for connectivity
   * (o rly?! :>)
   */
  private ConnectivityManager connectivityManager;

  /**
   * A {@link Context} object
   */
  private Context context;

  /**
   * Constructor
   * 
   * @param context
   *            a {@link Context} object
   */
  public ConnectivityHelper(Context context) {
    this.context = context;
    this.connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
  }

  /**
   * Checks the connectivity of the device according to the rules specified in
   * the {@link WebRequest} and the permissions the application has. If
   * permissions are not sufficient, <code>true</code> will be returned as a
   * fallback value.
   * 
   * @param wr
   *            the {@link WebRequest} whose rules will determine if the
   *            connectivity test fails
   * @return <code>true</code> if the device is connected according to the
   *         rules provided in {@link WebRequest}
   */
  public boolean checkConnectivityWebRequest(WebRequest wr) {
    return isConnected(wr) && isPingAble(wr);
  }

  private boolean isConnected(WebRequest wr) {
    if (wr.isCheckConnectivity()) {
      if (!hasAccessNetworkStatePermission()) {
        // @formatter:off
        LOGGER.warn("WebRequest (" + wr.getUrl() + ", " + wr.getId() + ") requested a connectivity check, but the caller lacks the required permission (ACCESS_NETWORK_STATE). Returning true");
        // @formatter:on
        return true;
      }
      NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
      return networkInfo == null ? false : networkInfo.isConnected();
    } else {
      LOGGER.info("WebRequest does not require connectivity check, returning true");
      return true;
    }
  }

  private boolean isPingAble(WebRequest wr) {
    if (wr.isCheckConnectivityPing()) {
      if (!hasChangeNetworkStatePermission()) {
        // @formatter:off
        LOGGER.warn("WebRequest (" + wr.getUrl() + ", " + wr.getId() + ") requested a connectivity PING check, but the caller lacks the required permission (CHANGE_NETWORK_STATE). Returning true");
        // @formatter:on
        return true;
      }

      InetAddress addr;
      try {
        addr = InetAddress.getByName(wr.getUrl().getHost());
        return addr.isReachable(5000);
      } catch (Throwable tr) {
        LOGGER.warn("Hostname could not be resolved and therefore not be pinged. Returning false", tr);
        return false;
      }
    } else {
      LOGGER.info("WebRequest does not require connectivity check, returning true");
      return true;
    }
  }

  private boolean hasAccessNetworkStatePermission() {
    return context.checkCallingOrSelfPermission(android.Manifest.permission.ACCESS_NETWORK_STATE) == PackageManager.PERMISSION_GRANTED;
  }

  private boolean hasChangeNetworkStatePermission() {
    return context.checkCallingOrSelfPermission(android.Manifest.permission.CHANGE_NETWORK_STATE) == PackageManager.PERMISSION_GRANTED;
  }
}
Java Source Code List
