CODEWITHSUNDEEP
androidandroid-intentandroid-activityandroid-context
Rikki Tikki Tavi
Rikki Tikki Tavi

Reputation: 3139

Starting Activity from non-activity class and passing context to it

I know that this is common question, but can't find my mistake. I need to pass Activity's Context to the RestClient class, which is non-activity. I do it like this:

public class RestClient {
 public void setContextRest(Context ctx)
    {
        this.context = ctx;
    }
    public Context getContextRest()
    {
        return  this.context;
    }
    public RestClient(Context context)
    {
        this.context = context;
    }
}

and in my Activity class : 

 RestClient helper = new RestClient(LoginActivity.this);
 helper.setContextRest(LoginActivity.this);

and this is how I get it in the RestClient: 

Intent i = new Intent(context, LoginActivity.class);
i.putExtra("relogin", true);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);

and I get 

   java.lang.NullPointerException
    at android.content.ComponentName.<init>(ComponentName.java:75)
    at android.content.Intent.<init>(Intent.java:2823)
    at com.library.RestClient.Execute(RestClient.java:276)
    at com.library.JSONParser.getJSONFromUrl(JSONParser.java:46)
at com.library.UserFunctions.loginUser(UserFunctions.java:76)
    at com.assignmentexpert.LoginActivity$LoginTask.doInBackground(LoginActivity.java:318)
    at com.assignmentexpert.LoginActivity$LoginTask.doInBackground(LoginActivity.java:1)
    at android.os.AsyncTask$2.call(AsyncTask.java:185)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
    at java.lang.Thread.run(Thread.java:1019)
    threadid=9: thread exiting with uncaught exception (group=0x40018578)

in the Intent i = new Intent(context, LoginActivity.class);. The problem is that context is null on some reason. Tell me please what it is?

Upvotes: 0

Views: 2141

Answers (3)

Rikki Tikki Tavi
Rikki Tikki Tavi

Reputation: 3139

Maybe its contradicts right designing patterns, but I used Singletone for my Activity and it works properly. Like this: 

      public static Context getInstance(){
        if (instance == null)
        {
            instance = LoginActivity._context;
        }
        return instance;
    }

Upvotes: 0

Pratik Sharma
Pratik Sharma

Reputation: 13415

Create your RestClient in this way:

public class RestClient {
    Context context;

    public RestClient(Context mcontext) {
       context = mcontext;
    }
    ....
    .... 
}

Now, initialize your restclient like this:

RestClient client;
client = new RestClient(getApplicationContext());

It will allow you to access context anywhere in your RestClient class.

Upvotes: 1

Nirav Tukadiya
Nirav Tukadiya

Reputation: 3417

  Intent i = new Intent(this.context, LoginActivity.class);

it should this.context instead of just context

Upvotes: 0

Related Questions