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如何在Android上检查互联网接入?地址从不超时

asynchronous networking android

603

Vidar Vestnes · 技术社区 · 15 年前

我有一个 AsyncTask 它应该检查对主机名的网络访问。但是 doInBackground() 永远不会超时。有人有线索吗?

public class HostAvailabilityTask extends AsyncTask<String, Void, Boolean> {

    private Main main;

    public HostAvailabilityTask(Main main) {
        this.main = main;
    }

    protected Boolean doInBackground(String... params) {
        Main.Log("doInBackground() isHostAvailable():"+params[0]);

        try {
            return InetAddress.getByName(params[0]).isReachable(30); 
        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;       
    }

    protected void onPostExecute(Boolean... result) {
        Main.Log("onPostExecute()");

        if(result[0] == false) {
            main.setContentView(R.layout.splash);
            return;
        }

        main.continueAfterHostCheck();
    }   
}

49 回复 | 直到 3 年前

1038

Bhargav Rao Ankit 6 年前

如果设备处于飞行模式(或者可能在没有可用网络的其他情况下), cm.getActiveNetworkInfo() 将 null ,因此您需要添加一个 无效的 检查

修改( Eddie's solution )下:

public boolean isOnline() {
    ConnectivityManager cm =
        (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    return netInfo != null && netInfo.isConnectedOrConnecting();
}

AndroidManifest.xml :

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

netInfo.isConnected() 而不是 netInfo.isConnectedOrConnecting

628

Aryeetey Solomon Aryeetey 3 年前

网络连接/互联网接入

isConnectedOrConnecting() (用于大多数答案)检查是否有网络联系
要知道这些网络中是否有 互联网

A) Ping服务器(简单)

// ICMP 
public boolean isOnline() {
    Runtime runtime = Runtime.getRuntime();
    try {
        Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
        int     exitValue = ipProcess.waitFor();
        return (exitValue == 0);
    }
    catch (IOException e)          { e.printStackTrace(); }
    catch (InterruptedException e) { e.printStackTrace(); }

    return false;
}

+ 可以在主线程上运行

- 在一些旧设备(Galays S3等)上不工作,如果没有可用的internet,它会阻塞一段时间。

B) 连接到Internet上的插座(高级)

// TCP/HTTP/DNS (depending on the port, 53=DNS, 80=HTTP, etc.)
public boolean isOnline() {
    try {
        int timeoutMs = 1500;
        Socket sock = new Socket();
        SocketAddress sockaddr = new InetSocketAddress("8.8.8.8", 53);

        sock.connect(sockaddr, timeoutMs);
        sock.close();

        return true;
    } catch (IOException e) { return false; }
}

非常快(无论哪种方式),适用于所有设备, 非常可信赖的

-

这在每台设备上都能非常可靠地工作,而且速度非常快。但它需要在单独的任务中运行(例如。 ScheduledExecutorService 或 AsyncTask ).

它真的够快吗?

是的,非常快;-)
除了在互联网上测试之外,没有可靠的方法来检查互联网吗?
如果DNS关闭了怎么办?

谷歌DNS(例如。 8.8.8.8 1 ].这么说吧,你的应用程序可能不会成为热门话题。

需要哪些权限?

<uses-permission android:name="android.permission.INTERNET" />

额外:一次 `RxJava/RxAndroid` 示例(科特林)

fun hasInternetConnection(): Single<Boolean> {
  return Single.fromCallable {
    try {
      // Connect to Google DNS to check for connection
      val timeoutMs = 1500
      val socket = Socket()
      val socketAddress = InetSocketAddress("8.8.8.8", 53)
    
      socket.connect(socketAddress, timeoutMs)
      socket.close()
  
      true
    } catch (e: IOException) {
      false
    }
  }
  .subscribeOn(Schedulers.io())
  .observeOn(AndroidSchedulers.mainThread())
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    hasInternetConnection().subscribe { hasInternet -> /* do something */}

额外:一次 `RxJava/RxAndroid` 示例(Java)

public static Single<Boolean> hasInternetConnection() {
    return Single.fromCallable(() -> {
        try {
            // Connect to Google DNS to check for connection
            int timeoutMs = 1500;
            Socket socket = new Socket();
            InetSocketAddress socketAddress = new InetSocketAddress("8.8.8.8", 53);

            socket.connect(socketAddress, timeoutMs);
            socket.close();

            return true;
        } catch (IOException e) {
            return false;
        }
    }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread());
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    hasInternetConnection().subscribe((hasInternet) -> {
        if(hasInternet) {

        }else {

        }
    });

实例

警告: 已弃用,应替换为应用程序的线程调度、Kotlin协程、Rx、。。。

class InternetCheck extends AsyncTask<Void,Void,Boolean> {

    private Consumer mConsumer;
    public  interface Consumer { void accept(Boolean internet); }

    public  InternetCheck(Consumer consumer) { mConsumer = consumer; execute(); }

    @Override protected Boolean doInBackground(Void... voids) { try {
        Socket sock = new Socket();
        sock.connect(new InetSocketAddress("8.8.8.8", 53), 1500);
        sock.close();
        return true;
    } catch (IOException e) { return false; } }

    @Override protected void onPostExecute(Boolean internet) { mConsumer.accept(internet); }
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    new InternetCheck(internet -> { /* do something with boolean response */ });

297

Jeff Axelrod 12 年前

不需要太复杂。最简单的框架方式是使用 ACCESS_NETWORK_STATE

public boolean isOnline() {
    ConnectivityManager cm =
        (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    return cm.getActiveNetworkInfo() != null && 
       cm.getActiveNetworkInfo().isConnectedOrConnecting();
}

你也可以使用 requestRouteToHost 如果您有特定的主机和连接类型(wifi/mobile)。

您还需要:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

在你的android清单中。

Jeff Axelrod 12 年前

getActiveNetworkInfo() 要工作,您需要将以下内容添加到清单中。

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Freewind thk 12 年前

请看一下ConnectivityManager类。您可以使用此类获取主机上活动连接的信息。 http://developer.android.com/reference/android/net/ConnectivityManager.html

编辑:您可以使用

Context.getSystemService(Context.CONNECTIVITY_SERVICE)
    .getNetworkInfo(ConnectivityManager.TYPE_MOBILE)

或

Context.getSystemService(Context.CONNECTIVITY_SERVICE)
    .getNetworkInfo(ConnectivityManager.TYPE_WIFI)

并解析返回的NetworkInfo对象的DetailedState枚举

编辑:要确定是否可以访问主机,可以使用

Context.getSystemService(Context.CONNECTIVITY_SERVICE)
    .requestRouteToHost(TYPE_WIFI, int hostAddress)

ConnectivityManager cm = Context.getSystemService(Context.CONNECTIVITY_SERVICE);
cm.yourMethodCallHere();

Melquiades Mohsen mokhtari 11 年前

检查此代码。。。这对我很有效:)

public static void isNetworkAvailable(final Handler handler, final int timeout) {
    // ask fo message '0' (not connected) or '1' (connected) on 'handler'
    // the answer must be send before before within the 'timeout' (in milliseconds)

    new Thread() {
        private boolean responded = false;   
        @Override
        public void run() { 
            // set 'responded' to TRUE if is able to connect with google mobile (responds fast) 
            new Thread() {      
                @Override
                public void run() {
                    HttpGet requestForTest = new HttpGet("http://m.google.com");
                    try {
                        new DefaultHttpClient().execute(requestForTest); // can last...
                        responded = true;
                    } 
                    catch (Exception e) {
                    }
                } 
            }.start();

            try {
                int waited = 0;
                while(!responded && (waited < timeout)) {
                    sleep(100);
                    if(!responded ) { 
                        waited += 100;
                    }
                }
            } 
            catch(InterruptedException e) {} // do nothing 
            finally { 
                if (!responded) { handler.sendEmptyMessage(0); } 
                else { handler.sendEmptyMessage(1); }
            }
        }
    }.start();
}

然后,我定义处理程序:

Handler h = new Handler() {
    @Override
    public void handleMessage(Message msg) {

        if (msg.what != 1) { // code if not connected

        } else { // code if connected

        }   
    }
};

…并启动测试:

isNetworkAvailable(h,2000); // get the answser within 2000 ms

Vladtn 14 年前

在处找到并从此处修改(!) link

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

如果您正在访问INTERNET,您可能已经拥有INTERNET权限。然后,允许测试连接性的布尔函数是:

private boolean checkInternetConnection() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    // test for connection
    if (cm.getActiveNetworkInfo() != null
            && cm.getActiveNetworkInfo().isAvailable()
            && cm.getActiveNetworkInfo().isConnected()) {
        return true;
    } else {
        Log.v(TAG, "Internet Connection Not Present");
        return false;
    }
}

Dediqated Munish Katoch 11 年前

问 if(isOnline()){

您将获得是否存在连接以及是否可以连接到页面的状态代码 200 (稳定连接)。

确保添加正确的 INTERNET ACCESS_NETWORK_STATE

public boolean isOnline() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    if (netInfo != null && netInfo.isConnected()) {
        try {
            URL url = new URL("http://www.google.com");
            HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
            urlc.setConnectTimeout(3000);
            urlc.connect();
            if (urlc.getResponseCode() == 200) {
                return new Boolean(true);
            }
        } catch (MalformedURLException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    return false;
}

Musculaa 10 年前

它确实对我有用:

private Boolean isNetworkAvailable() {
ConnectivityManager connectivityManager 
      = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnectedOrConnecting();}

要验证internet访问,请执行以下操作:

public Boolean isOnline() {
    try {
        Process p1 = java.lang.Runtime.getRuntime().exec("ping -c 1 www.google.com");
        int returnVal = p1.waitFor();
        boolean reachable = (returnVal==0);
        return reachable;
    } catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return false;
}

Mohamed Embaby 7 年前

有不止一种方法

第一,最短但效率低的方法

仅需要网络状态权限

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

那么这个方法,,

 public boolean activeNetwork () {
        ConnectivityManager cm =
                (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        boolean isConnected = activeNetwork != null &&
                activeNetwork.isConnected();

        return isConnected;

    }

如答案所示 ConnectivityManager 这是一个解决方案,我只是在一个方法中添加了它。这是一个简化的方法
连接管理器 如果存在网络接入而非互联网接入,则返回true。这意味着如果您的WiFi连接到路由器,但路由器没有互联网,则返回true,并检查连接可用性

第二,有效途径

需要网络状态和Internet权限

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />

然后这个班,,

 public class CheckInternetAsyncTask extends AsyncTask<Void, Integer, Boolean> {

        private Context context;

        public CheckInternetAsyncTask(Context context) {
            this.context = context;
        }

        @Override
        protected Boolean doInBackground(Void... params) {

            ConnectivityManager cm =
                    (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

            assert cm != null;
            NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
            boolean isConnected = activeNetwork != null &&
                    activeNetwork.isConnected();


            if (isConnected) {
                try {
                    HttpURLConnection urlc = (HttpURLConnection)
                            (new URL("http://clients3.google.com/generate_204")
                                    .openConnection());
                    urlc.setRequestProperty("User-Agent", "Android");
                    urlc.setRequestProperty("Connection", "close");
                    urlc.setConnectTimeout(1500);
                    urlc.connect();
                    if (urlc.getResponseCode() == 204 &&
                            urlc.getContentLength() == 0)
                        return true;

                } catch (IOException e) {
                    Log.e("TAG", "Error checking internet connection", e);
                    return false;
                }
            } else {
                Log.d("TAG", "No network available!");
                return false;
            }


            return null;
        }

        @Override
        protected void onPostExecute(Boolean result) {
            super.onPostExecute(result);
            Log.d("TAG", "result" + result);

            if(result){
                // do ur code
            }

        }


    }

CheckInternetAsyncTask

new CheckInternetAsyncTask(getApplicationContext()).execute();

你必须上网 AsyncTask ,否则它会抛出 android.os.NetworkOnMainThreadException
连接管理器 用于在true发送请求(Ping)时检查网络访问
http://clients3.google.com/generate_204 ,这个众所周知的URL会返回一个HTTP状态为204的空页面。这比 http://www.google.com 阅读 this . 如果你有一个网站,你最好把你的网站,而不是谷歌,只有当你在应用程序中使用它

Community kfsone 7 年前

以下是我使用的方法:

public boolean isNetworkAvailable(final Context context) {
    return ((ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo() != null;
}

public boolean isNetworkAvailable(final Context context) {
    final ConnectivityManager connectivityManager = ((ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE));
    return connectivityManager.getActiveNetworkInfo() != null && connectivityManager.getActiveNetworkInfo().isConnected();
}

以下是如何使用该方法:

if (isNetworkAvailable(context)) {
    // code here
} else {
    // code
}

所需许可:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

https://stackoverflow.com/a/16124915/950427

Nickolaus 12 年前

到目前为止,我所看到的最短、最干净的方法应该是:

public final static boolean isConnected( Context context )
{   
   final ConnectivityManager connectivityManager = 
         (ConnectivityManager) context.getSystemService( Context.CONNECTIVITY_SERVICE );  
   final NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();    
   return networkInfo != null && networkInfo.isConnected();
}

PS:这不会ping任何主机,它只是检查连接状态,因此,如果您的路由器没有internet连接,并且您的设备已连接到它,则此方法将返回虽然你没有互联网。
对于实际测试,我建议执行HttpHead请求 (例如,访问www.google.com) 并检查状态,如果 200行 一切正常,您的设备已连接互联网。

user1528493 11 年前

移动设备上的一个重要用例是确保存在实际连接。当移动用户进入带有“专属门户”的Wifi网络时,这是一个常见问题,他们需要在其中登录。我在后台使用这个阻塞函数来确保连接存在。

/*
 * Not Thread safe. Blocking thread. Returns true if it
 * can connect to URL, false and exception is logged.
 */
public boolean checkConnectionHttps(String url){
    boolean responded = false;
    HttpGet requestTest = new HttpGet(url);
    HttpParams params = new BasicHttpParams();
    HttpConnectionParams.setConnectionTimeout(params, 3000);
    HttpConnectionParams.setSoTimeout(params, 5000);
    DefaultHttpClient client = new DefaultHttpClient(params);
    try {
        client.execute(requestTest);
        responded = true;
    } catch (ClientProtocolException e) {
        Log.w(MainActivity.TAG,"Unable to connect to " + url + " " + e.toString());
    } catch (IOException e) {
        Log.w(MainActivity.TAG,"Unable to connect to " + url + " " + e.toString());
        e.printStackTrace();
    }
    return responded;
}

Hawklike 4 年前

科特林与合作项目

ViewModel ,其中 viewModelScope LiveData 我通知一个活动有关连接。

视图模型

 fun checkInternetConnection(timeoutMs: Int) {
        viewModelScope.launch(Dispatchers.IO) {
            try {
                val socket = Socket()
                val socketAddress = InetSocketAddress("8.8.8.8", 53)

                socket.connect(socketAddress, timeoutMs)
                socket.close()

                _connection.postValue(true)
            }
            catch(ex: IOException) {
                _connection.postValue(false)
            }
        }
    }

 private val _connection = MutableLiveData<Boolean>()
 val connection: LiveData<Boolean> = _connection

活动

 private fun checkInternetConnection() {
     viewModel.connection.observe(this) { hasInternet ->
         if(!hasInternet) {
             //hasn't connection
         }
         else {
            //has connection
         }
     }
  }

Vidar Vestnes 15 年前

Im使用此代码而不是InetAddress:

    try {

        URL url = new URL("http://"+params[0]);

        HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
        urlc.setRequestProperty("User-Agent", "Android Application:"+Z.APP_VERSION);
        urlc.setRequestProperty("Connection", "close");
        urlc.setConnectTimeout(1000 * 30); // mTimeout is in seconds
        urlc.connect();
        if (urlc.getResponseCode() == 200) {
            Main.Log("getResponseCode == 200");
            return new Boolean(true);
        }
    } catch (MalformedURLException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Emre Yazici 13 年前

您可以迭代所有网络连接,并检查是否至少有一个可用连接:

public boolean isConnected() {
    boolean connected = false;

    ConnectivityManager cm = 
        (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    if (cm != null) {
        NetworkInfo[] netInfo = cm.getAllNetworkInfo();

        for (NetworkInfo ni : netInfo) {
            if ((ni.getTypeName().equalsIgnoreCase("WIFI")
                    || ni.getTypeName().equalsIgnoreCase("MOBILE"))
                    && ni.isConnected() && ni.isAvailable()) {
                connected = true;
            }

        }
    }

    return connected;
}

laplasz 12 年前

ConnectivityManager cm =
    (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

应该在那里调用,或者您需要将活动实例(上下文)下推到连接处理程序类,以便能够检查那里的连接状态 未知后异常

JSONObject jObj = null;
Boolean responded = false;
HttpGet requestForTest = new HttpGet("http://myserver.com");
try {
    new DefaultHttpClient().execute(requestForTest);
    responded = true;
} catch (UnknownHostException e) {
    jObj = new JSONObject();
    try {
        jObj.put("answer_code", 1);
        jObj.put("answer_text", "No available connection");
    } catch (Exception e1) {}
    return jObj;
} catch (IOException e) {
    e.printStackTrace();
}

通过这种方式,我可以处理这个案例以及同一类中的其他案例(我的服务器总是使用json字符串进行响应)

selva_pollachi 11 年前

这对我很有用。试试看。

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    try {
        URL url = new URL("http://stackoverflow.com/posts/11642475/edit" );
        //URL url = new URL("http://www.nofoundwebsite.com/" );
        executeReq(url);
        Toast.makeText(getApplicationContext(), "Webpage is available!", Toast.LENGTH_SHORT).show();
    }
    catch(Exception e) {
        Toast.makeText(getApplicationContext(), "oops! webpage is not available!", Toast.LENGTH_SHORT).show();
    }
}

private void executeReq(URL urlObject) throws IOException
{
    HttpURLConnection conn = null;
    conn = (HttpURLConnection) urlObject.openConnection();
    conn.setReadTimeout(30000);//milliseconds
    conn.setConnectTimeout(3500);//milliseconds
    conn.setRequestMethod("GET");
    conn.setDoInput(true);

    // Start connect
    conn.connect();
    InputStream response =conn.getInputStream();
    Log.d("Response:", response.toString());
}}

WonderWorker Sakal 9 年前

public boolean isNetworkAvailable(bool SlowButMoreReliable) {
    bool Result = false; 
    try {
        if(SlowButMoreReliable){
            ConnectivityManager MyConnectivityManager = null;
            MyConnectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

            NetworkInfo MyNetworkInfo = null;
            MyNetworkInfo = MyConnectivityManager.getActiveNetworkInfo();

            Result = MyNetworkInfo != null && MyNetworkInfo.isConnected();

        } else
        {
            Runtime runtime = Runtime.getRuntime();
            Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");

            int i = ipProcess.waitFor();

            Result = i== 0;

        }

    } catch(Exception ex)
    {
        //Common.Exception(ex); //This method is one you should have that displays exceptions in your log
    }
    return Result;
}

Chilledrat Engr.Ammad 12 年前

检查Android网络/互联网连接状态并不复杂。下面 DetectConnection

import android.content.Context;
import android.net.ConnectivityManager;

public class DetectConnection {
    public static boolean checkInternetConnection(Context context) {
        ConnectivityManager con_manager = (ConnectivityManager) context
                                .getSystemService(Context.CONNECTIVITY_SERVICE);

        if (con_manager.getActiveNetworkInfo() != null
            && con_manager.getActiveNetworkInfo().isAvailable()
            && con_manager.getActiveNetworkInfo().isConnected()) {
                return true;
        } else {
            return false;
        }
    }
}

欲了解更多详情,请访问 How to Check Android Network / Internet Connectivity Status

Lo Juego 12 年前

public static boolean isOnline() {
    try {
    InetAddress.getByName("google.com").isReachable(3);

    return true;
    } catch (UnknownHostException e){
    return false;
    } catch (IOException e){
    return false;
    }
    }

Mahendra Liya 11 年前

Utils 类别:

public static boolean isNetworkAvailable(Context context) {
        ConnectivityManager connectivityManager 
              = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

kleopatra Aji kattacherry 11 年前

public class Network {

Context context;

public Network(Context context){
    this.context = context;
}

public boolean isOnline() {
    ConnectivityManager cm =
            (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);

    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    return activeNetwork != null &&
                          activeNetwork.isConnectedOrConnecting();
}

}

Akshay Paliwal 10 年前

您可以使用此方法检测网络可用性-

public static boolean isDeviceOnline(Context context) {
        boolean isConnectionAvail = false;
        try {
            ConnectivityManager cm = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo netInfo = cm.getActiveNetworkInfo();
            return netInfo.isConnected();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return isConnectionAvail;
    }

k4dima 9 年前

这在android文档中有介绍 http://developer.android.com/training/monitoring-device-state/connectivity-monitoring.html

Jorgesys 8 年前

非常重要的是检查我们是否与 isAvailable() 如果可能的话,可以与 isConnected()

private static ConnectivityManager manager;

public static boolean isOnline(Context context) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
    return networkInfo != null && networkInfo.isAvailable() && networkInfo.isConnected();
}

您可以终止网络活动的类型 WiFi

public static boolean isConnectedWifi(Context context) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
    return networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_WIFI;
}

还是手机 MÃ³vil :

public static boolean isConnectedMobile(Context context) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
    return networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_MOBILE;
}

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <uses-permission android:name="android.permission.INTERNET" />

Jaymin Panchal Orxan Kerimli 8 年前

我已经应用了@Levit提供的解决方案,并创建了不会调用额外Http请求的函数。

Unable to Resolve Host

public static boolean isInternetAvailable(Context context) {
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    if (activeNetwork == null) return false;

    switch (activeNetwork.getType()) {
        case ConnectivityManager.TYPE_WIFI:
            if ((activeNetwork.getState() == NetworkInfo.State.CONNECTED ||
                    activeNetwork.getState() == NetworkInfo.State.CONNECTING) &&
                    isInternet())
                return true;
            break;
        case ConnectivityManager.TYPE_MOBILE:
            if ((activeNetwork.getState() == NetworkInfo.State.CONNECTED ||
                    activeNetwork.getState() == NetworkInfo.State.CONNECTING) &&
                    isInternet())
                return true;
            break;
        default:
            return false;
    }
    return false;
}

private static boolean isInternet() {

    Runtime runtime = Runtime.getRuntime();
    try {
        Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
        int exitValue = ipProcess.waitFor();
        Debug.i(exitValue + "");
        return (exitValue == 0);
    } catch (IOException | InterruptedException e) {
        e.printStackTrace();
    }

    return false;
}

现在就这样说吧,

if (!isInternetAvailable(getActivity())) {
     //Show message
} else {
     //Perfoem the api request
}

miguel 9 年前

使用ConnectivityManager的其他答案是错误的,因为拥有网络连接并不意味着您可以访问internet。例如,用户可能连接到咖啡店的WiFi门户,但无法访问互联网。要检查internet是否可访问,您必须尝试连接到实际的服务器。通常,当您想这样做时,您会想到要连接到的特定服务器,因此请继续检查您是否可以连接到该服务器。这里有一个检查服务器连接的简单方法。

private boolean isOnTheInternet() {
    try {
        URLConnection urlConnection = new URL("http://yourserver").openConnection();
        urlConnection.setConnectTimeout(400);
        urlConnection.connect();
        return true;
    } catch (Exception e) {
        return false;
    }
}

设置ConnectTimeout的原因是,否则它默认为TCP超时,可能长达数秒。

另外请注意,Android不允许您在主线程上运行此功能。

Rajesh Jadav 8 年前

我已经看完了所有的答案,我提出了我自己的答案,首先检查互联网是否可用,如果互联网可用,然后检查它是否处于活动状态。

我已经包括了所有必要的方法和类来检查活动的互联网连接。

NetworkUtils.class

public class NetworkUtils {

    public static final int STATUS_CONNECTED = 0 ;

    public static boolean isInternetAvailable(Context ctx){
        ConnectivityManager cm = (ConnectivityManager)ctx.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

    public static int isInternetActiveWithPing() {
        try {
            Runtime runtime = Runtime.getRuntime();
            Process process = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
            int exitValue = process.waitFor();
            return exitValue;
        } catch (Exception ex) {
            return -1;
        }
    }

    public static boolean isInternetActiveWithInetAddress() {
        try {
            InetAddress inetAddress = InetAddress.getByName("www.google.com");
            return inetAddress != null && !inetAddress.toString().equals("");
        } catch (Exception ex) {
            return false;
        }
    }

    public static void displayInternetConnectionMessage(Context ctx){
        Toast.makeText(ctx, "Check Internet Connection", Toast.LENGTH_SHORT).show();
    }
}

您可以使用以下代码检查Internet是否处于活动状态:

 private void checkInternetConnection() {
        if (NetworkUtils.isInternetAvailable(this)) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    if (NetworkUtils.isInternetActiveWithPing() == NetworkUtils.STATUS_CONNECTED) {
                        performNetworkingOperations();
                    } else {
                        if (NetworkUtils.isInternetActiveWithInetAddress()) {
                            performNetworkingOperations();
                        } else {
                            displayConnectionMessage();
                        }
                    }
                }
            }).start();

        } else {
            displayConnectionMessage();
        }
    }

    private void performNetworkingOperations() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                Toast.makeText(MainActivity.this, "Internet is Available", Toast.LENGTH_SHORT).show();
            }
        });
    }

    private void displayConnectionMessage() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                NetworkUtils.displayInternetConnectionMessage(MainActivity.this);
            }
        });
    }

Michele La Ferla 10 年前

public class ConnectionStatus {

    private Context _context;

    public ConnectionStatus(Context context) {
        this._context = context;
    }

    public boolean isConnectionAvailable() {
        ConnectivityManager connectivity = (ConnectivityManager) _context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivity != null) {
            NetworkInfo[] info = connectivity.getAllNetworkInfo();
            if (info != null)
                for (int i = 0; i < info.length; i++)
                    if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                        return true;
                    }
        }
        return false;
    }
}

true 否则 false

然后,MainActivity中的以下方法调用前面描述的方法的结果,并提示用户采取相应的行动:

public void addListenerOnWifiButton() {
        Button btnWifi = (Button)findViewById(R.id.btnWifi);

        iia = new ConnectionStatus(getApplicationContext());

        isConnected = iia.isConnectionAvailable();
        if (!isConnected) {
            btnWifi.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS));
                    Toast.makeText(getBaseContext(), "Please connect to a hotspot",
                            Toast.LENGTH_SHORT).show();
                }
            });
        }
        else {
            btnWifi.setVisibility(4);
            warning.setText("This app may use your mobile data to update events and get their details.");
        }
    }

在上面的代码中,如果结果为false(因此没有互联网连接),用户将被带到Android wi-fi面板,在那里他将被提示连接到wi-fi热点。