Android - Checking server or url availability

Question

Can someone help me with this code. I found so many results but nothing seems to work. As android updates, some or most of its old code deprecates. Maybe there someone who would know how.

Example: URL = "192.168.1.14"

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

I am using Android Studio and I already put the above code in the AndroidManifest.xml

My current Android build for my project is Android 4.0

Forgot to mention that I used WAMP Server and MySQL, so the URL is from the server computer managing the website that I am attempting to access

The code below uses android device ip address specified above. But keeps returning false.

public Boolean isConnectedToServer(String url) {
    try {
        HttpURLConnection.setFollowRedirects(false);
        HttpURLConnection con =  (HttpURLConnection) new URL(url).openConnection();
        con.setRequestMethod("HEAD");

        Toast.makeText(LogIn.this, "NETWORK CONNECTED", Toast.LENGTH_LONG).show();
        if(con.getResponseCode() == HttpURLConnection.HTTP_OK)
        {
            return true;
        }
        else
        {
            return false;
        }
    } catch (Exception e) {
        Toast.makeText(LogIn.this, "NETWORK ERROR CONNECTION", Toast.LENGTH_LONG).show();
        Log.e("APP", "exception", e);
        return false;
    }
}

The code below same as before uses android device ip address specified above but loops the array of ip or in this case the entire network. But still keeps returning false.

public Boolean isConnectedToServer(String url) {
    int index = url.lastIndexOf(".");
    Boolean result = false;
    for(int octet = 2; octet <= 254; octet++) {
        try {
            HttpURLConnection.setFollowRedirects(false);
            HttpURLConnection con = (HttpURLConnection) new URL("http://" + url.substring(0, index + 1) + "" + octet + "/").openConnection();
            con.setRequestMethod("HEAD");

            //Toast.makeText(LogIn.this, "NETWORK CONNECTED", Toast.LENGTH_LONG).show();
            if (con.getResponseCode() == HttpURLConnection.HTTP_OK)
            {
                result = true;
                break;
            }
            else
            {
                result = false;
            }
        } catch (Exception e) {
            //Toast.makeText(LogIn.this, "NETWORK ERROR CONNECTION", Toast.LENGTH_LONG).show();
            Log.e("APP", "exception", e);
            result = false;
        }
    }
    return result;
}

Any suggestion or fix to code?

Exception returns: android.os.NetworkOnMainThreadException

Check what error you're getting. You probably need to get off the UI thread. — SLaks, Feb 03 '16 at 04:17
Did you specify any port number? If not, it's normally port 9000. Try 192.168.1.14:9000 — Jiyeh, Feb 03 '16 at 04:18
Example: 'http://192.168.1.14:9000/Foldername' <- like this? — C3D41C, Feb 03 '16 at 04:21
i believe the code will not run and throw running network on UI thread exception. — kopikaokao, Feb 03 '16 at 04:24
Also, don't just toast a custom message. Actually print your exception from the catch and read it — OneCricketeer, Feb 03 '16 at 04:24
Either shift the code onto another thread or change the strictmode to enable network on the main ui thread. http://stackoverflow.com/questions/28862525/android-annotations-background-networkonmainthreadexception — Ophitect, Feb 03 '16 at 04:49
Possible duplicate of [Android - android.os.NetworkOnMainThreadException](http://stackoverflow.com/questions/9413625/android-android-os-networkonmainthreadexception) — Sufian, Sep 27 '16 at 11:24

score 0 · Answer 1 · answered Feb 03 '16 at 05:05

0

All network operations should be done using asyntask.since UI thread is shared by other resources in the phone you cannot run time dependent operation.

answered Feb 03 '16 at 05:05

RanjitRock

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Thank you for the suggestion. I will try a research about AsynTask. – C3D41C Feb 03 '16 at 05:10
Please flag duplicate answers instead of answering them. This is a much repeated question on SO. – Sufian Sep 27 '16 at 11:25

Android - Checking server or url availability

1 Answers1