Android

Why bytecode cannot be run in Android?

b1.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View view) {
              SparseBooleanArray checked =listView.getCheckedItemPositions();
              ArrayList<String> selectedItems = new ArrayList<String>();
              String str = null;
              for (int i = 0; i < checked.size(); i++) {
                  int position;
                  position = checked.keyAt(i);
                  if (checked.valueAt(i))
                      selectedItems.add(String.valueOf(arrayAdapter.getItem(position)));
                  str = listView.getItemAtPosition(i).toString();
                  str=str.replaceAll("[^\\d.]", "");
              }
              Intent i = new Intent(getApplicationContext(), Activation.class);
              i.putExtra("contact", str);
              startActivity(i);
              arrayAdapter.remove(str);
          }
      });

Intent i = getIntent();
                String product = i.getStringExtra("contact");
                text.setText(product);