edit spinner in one activity from another activity - android-activity

Question

i created Activity5 for manage values on other activities...
in Activity3 i have a spinner...
Spinner spinner1;
ArrayList<String> SAlist;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity3);
getActionBar().setDisplayHomeAsUpEnabled(true);
Intent intent = getIntent();
ArrayList<String> SAList = intent.getStringArrayListExtra("StringArrayList");
spinner1=(Spinner) findViewById(R.id.spinner1);
ArrayAdapter<String> adp=new ArrayAdapter<String>(this,
android.R.layout.simple_dropdown_item_1line,SAList);
spinner1.setAdapter(adp);
}
i think if i build new spinner (for showing it to user) in activity5 and edit it , then passing array list of this spinner to activity3, this is possible...
Activity5:
Spinner sp;
EditText et;
ArrayList<String> li;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main_activity5);
getActionBar().setDisplayHomeAsUpEnabled(true);
li=new ArrayList<String>();
li.add("first item");
sp=(Spinner) findViewById(R.id.spinner1);
Button butt=(Button) findViewById(R.id.button1);
Button butt1=(Button) findViewById(R.id.button2);
et=(EditText)findViewById(R.id.editText1);
add();
butt.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
li.add(et.getText().toString());
et.setText(null);
add();
}
});
butt1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent intent = new Intent(MainActivity5.this, MainActivity3.class);
intent.putStringArrayListExtra("StringArrayList", li);
startActivity(intent);
}
});
}
private void add() {
ArrayAdapter<String> adp=new ArrayAdapter<String>(this,
android.R.layout.simple_dropdown_item_1line,li);
sp.setAdapter(adp);
}
but when i launch app and open activity3 it shows "unfortunately app has stopped" !!!
help me plz!

Answer 1

when you open activity3 from main menu, on that event your getting SAList null,
try doing this,when SAList is null it will show empty spinner.
Intent intent = getIntent();
if(intent.getStringArrayListExtra("StringArrayList")!=null)
{
ArrayList<String> SAList = intent.getStringArrayListExtra("StringArrayList");
}else
{
ArrayList<String> SAList=new ArrayList<String>();
}