Question

Here is my onCreate() method. I am trying to pass a variable from one intent to this intent. That works fine. When I press back button and go back to previous intent to change the value, then the application crashes. And also when I change the orientation, the application crashes. I am getting “Nullpointer exception” at the pp.getData() method. It passes null argument into the function. How can I overcome this? do I need to add any other details?

public void onCreate(Bundle savedInstanceState) {

    // get intent data
    Intent i = getIntent();

    setQuery(i.getExtras().getString("query"));
    Log.v("query:", getQuery());

    userquery = getQuery();

    super.onCreate(savedInstanceState);
    setContentView(R.layout.product_view_layout);

    try {
        pp = new Parser(userquery);
        productData = pp.getData(asynctask, userquery);
    } catch (URISyntaxException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    mProductViewPagerAdapter = new ProductViewPagerAdapter(
            getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mProductViewPagerAdapter);

}

Answer 1

If the “query” extra doesn’t exist in the Intent then it will return null. You should perform a null check to make sure you don’t get nullPointerExceptions.

String query = i.getExtras().getString("query"));

if(query == null) {
    setQuery("");
}
else {
    setQuery(query);
}