use spinner java android code example

Example 1: spinner android

// Spinner element
      Spinner spinner = (Spinner) findViewById(R.id.spinner);
      
      // Spinner click listener
      spinner.setOnItemSelectedListener(this);
      
      // Spinner Drop down elements
      List<String> categories = new ArrayList<String>();
      categories.add("Automobile");
      categories.add("Business Services");
      categories.add("Computers");
      categories.add("Education");
      categories.add("Personal");
      categories.add("Travel");
      
      // Creating adapter for spinner
      ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, categories);
      
      // Drop down layout style - list view with radio button
      dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
      
      // attaching data adapter to spinner
      spinner.setAdapter(dataAdapter);

Example 2: how to set list data to android spinner

// setting branch data in manually and load to spBranchName
        List<String> branchList = new ArrayList<>();
        branchList.add("CHITTAGONG");
        branchList.add("DHAKA");

        ArrayAdapter<String> branchListAdapter = new ArrayAdapter<>(getActivity(),
                android.R.layout.simple_spinner_item, branchList);
        branchListAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spBranchName.setAdapter(branchListAdapter);