The JVM throws a NullPointerException at the point in a program where code tries to dereference a null reference. With Java SE 14, the NullPointerException offers helpful information about the premature termination of a program. Java SE 14 onwards, the JVM describes the variable (in terms of source code) with a null-detail message in the … Read more
The answer Kar0t is perfectly fine but this may help somebody. On my case I had a fragment inside of a fragment and I was getting the wrong FragmentManager. I just had to call: getChildFragmentManager() and then just find the Fragment as usual: fm.findFragmentById(R.id.fragment)
You must add following code for taking images from devices choosebtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent i1=new Intent(); i1.setType(“image/*”); i1.setAction(Intent.ACTION_GET_CONTENT); startActivityForResult(i1,1); } }); @Override protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) { super.onActivityResult(requestCode, resultCode, data); if(requestCode == 1 && resultCode == RESULT_OK && data != null && data.getData() != … Read more
The edit shows exactly the difference between code that works and code that doesn’t. This check always evaluates both of the conditions, throwing an exception if str is null: if (str == null | str.length() == 0) { Whereas this (using || instead of |) is short-circuiting – if the first condition evaluates to true, … Read more
You are missing the fact that Long.getLong(String str) is not supposed to parse a String to a long, but rather to return a long value of a system property represented by that string. As others have suggested, what you actually need is Long.parseLong(String str).
EDIT 2021: There is a new package that is sort of a hack featuring exactly this functionality in Python. Here is the repo: https://github.com/paaksing/nullsafe-python from nullsafe import undefined, _ value = _(variable).method() assert value is undefined assert not value assert value == None Works with AttributeError and KeyError aswell dic = {} assert _(dic)[“nah”] is … Read more
This to me sounds like a reasonably common problem that junior to intermediate developers tend to face at some point: they either don’t know or don’t trust the contracts they are participating in and defensively overcheck for nulls. Additionally, when writing their own code, they tend to rely on returning nulls to indicate something thus … Read more
I’m almost sure that this is caused when the thread finish its work but the activity is no longer visible. You should check if the getActivity() call return null, and … To apply corrections on your code, look at this: // (Calendar) Date function – Displays dateview on Card final boolean keepRunning1 = true; Thread … Read more
Naturally, it’s your choice. Whatever logic you write, it will define sorting rules. So ‘should’ isn’t really the right word here. If you want null to appear before any other element, something like this could do public int compare(MyBean o1, MyBean o2) { if (o1.getDate() == null) { return (o2.getDate() == null) ? 0 : … Read more
You need to call getSupportActionBar() on an ActionBarActivity. Do not call getActionBar() — that is not available on older devices, and for the new r21 edition of appcompat-v7, I would expect it to return null all the time, as the new ActionBarActivity disables and replaces the system action bar.