I investigate that problem but can not find any solution for my code. I have four classes. But i am sure, no problem on class named Connect(You will see its object on class JsonData below.)So i share the other three classes. My MainActivity is;
public class MainActivity extends Activity {
String keys[] = {"Message", "Subject", "MessageType", "SentTime", "ToName", "Id"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
JsonData.keys=keys;
JsonData jsonData = new JsonData();
ArrayList<HashMap<String, String>> dataList = new ArrayList<HashMap<String, String>>();
dataList= jsonData.GetData();
}
}
I send keyvalues for json and then take data from any url(it is private, i delete it) on class JsonData;
public class JsonData extends Activity{
Connect connect = new Connect();
private String url = "url";
static String keys[];
public ArrayList<HashMap<String, String>> GetData() {
JSONArray json = null;
ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
InternetCheck netCheck = new InternetCheck();
if(netCheck.isInternetOn()){
try {
JSONObject result = connect
.connect(url);
json = result.getJSONArray("d");
for (int i = 0; i < json.length(); i++) {
HashMap<String, String> hashmap = new HashMap<String, String>();
JSONObject json2 = json.getJSONObject(i);
for (int j = 0; j < keys.length; j++){
hashmap.put(keys[j], json2.getString(keys[j]));
}
mylist.add(hashmap);
}
} catch (Exception e) {
e.printStackTrace();
}
}
else
Toast.makeText(this, " Check Internet Options. ", Toast.LENGTH_LONG).show();
return mylist;
}
}
In this class, i check internet connection from object netCheck. I think my problem is on that class. InternetCheck.java ;
public class InternetCheck extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public final boolean isInternetOn() {
// get Connectivity Manager object to check connection
ConnectivityManager connec = (ConnectivityManager)getSystemService(getBaseContext().CONNECTIVITY_SERVICE);
// Check for network connections
if ( connec.getNetworkInfo(0).getState() == android.net.NetworkInfo.State.CONNECTED ||
connec.getNetworkInfo(0).getState() == android.net.NetworkInfo.State.CONNECTING ||
connec.getNetworkInfo(1).getState() == android.net.NetworkInfo.State.CONNECTING ||
connec.getNetworkInfo(1).getState() == android.net.NetworkInfo.State.CONNECTED ) {
return true;
} else if ( connec.getNetworkInfo(0).getState() == android.net.NetworkInfo.State.DISCONNECTED || connec.getNetworkInfo(1).getState() == android.net.NetworkInfo.State.DISCONNECTED ) {
return false;
}
return false;
}
}
I am suspecting from the commented line **//get Connectivity Manager object to check connection ** . Finally my Logcat;
08-27 10:13:45.449: E/AndroidRuntime(24925): FATAL EXCEPTION: main
08-27 10:13:45.449: E/AndroidRuntime(24925): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.jsonparser/com.example.jsonparser.MainActivity}: java.lang.IllegalStateException: System services not available to Activities before onCreate()
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1659)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread.access$1500(ActivityThread.java:121)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.os.Handler.dispatchMessage(Handler.java:99)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.os.Looper.loop(Looper.java:130)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread.main(ActivityThread.java:3768)
08-27 10:13:45.449: E/AndroidRuntime(24925): at java.lang.reflect.Method.invokeNative(Native Method)
08-27 10:13:45.449: E/AndroidRuntime(24925): at java.lang.reflect.Method.invoke(Method.java:507)
08-27 10:13:45.449: E/AndroidRuntime(24925): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)
08-27 10:13:45.449: E/AndroidRuntime(24925): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)
08-27 10:13:45.449: E/AndroidRuntime(24925): at dalvik.system.NativeStart.main(Native Method)
08-27 10:13:45.449: E/AndroidRuntime(24925): Caused by: java.lang.IllegalStateException: System services not available to Activities before onCreate()
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.Activity.getSystemService(Activity.java:3536)
08-27 10:13:45.449: E/AndroidRuntime(24925): at com.example.jsonparser.InternetCheck.isInternetOn(InternetCheck.java:19)
08-27 10:13:45.449: E/AndroidRuntime(24925): at com.example.jsonparser.JsonData.GetData(JsonData.java:25)
08-27 10:13:45.449: E/AndroidRuntime(24925): at com.example.jsonparser.MainActivity.onCreate(MainActivity.java:21)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-27 10:13:45.449: E/AndroidRuntime(24925): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1623)
I'm saying again, i looked over other questions but no solution available for me. Thanks in advance.
Your JSONParser extends activity but it's not an activity. Remove the extends Activity and call it as an object.
You'll also need to remove the extends Activity from your InternetCheck class.
Then pass your context to the JSONData class and use your InternetCheck class like this
Then in your InternetCheck class accept the context in the constructor and replace all
with your
context
variableTry to change:
InternetCheck
is a Activity class. Activity is started bystartActivity
.getSystemService
requires activity context.http://developer.android.com/reference/android/content/Context.html#getSystemService(java.lang.String)
You have this
And you do this
What you need is a utility class not an activity class. Also if you are doing network related operation do it in a
thread
orAsynctask
To check in any activity
You may be connected to wifi but wifi may not be connect to net. This only checks for network connection availability.
Edit: