我有edittext，倒计时，列表视图，我的项目上的共享首选项。我的应用程序可以工作。我的倒计时计时器在完成我添加文本我的列表视图。我用共享的偏好保存这个。如果我打开新的倒计时计时器后，完成它添加新的文本到listview，但它只保存最后一个文本怎么可能ı 在listview中保存所有文本。

public class pomodoro extends AppCompatActivity {
        Button baslat,backhome,bitir;
            EditText edittextcalisma,edittextmola;
            CountDownTimer calisma,mola;
            ArrayList<String> list = new ArrayList<String>();
            ArrayAdapter arrayAdapter;
            ListView listView;

            @Override
            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_pomodoro);
                 LoadPreferences();

                listView=(ListView)findViewById(R.id.listv);
                arrayAdapter = new ArrayAdapter<String>(
                        this,R.layout.list_view,R.id.textitem, list);
                listView.setAdapter(arrayAdapter);
                bitir=findViewById(R.id.bitirbutton);
                baslat = findViewById(R.id.baslatbutton);
                edittextcalisma = findViewById(R.id.edittextcalisma);
                edittextmola = findViewById(R.id.edittextmola);

                baslat.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {

                        closeKeyboard();

                        final int molapo = Integer.valueOf(edittextmola.getText().toString());
                        final int calismapo = Integer.valueOf(edittextcalisma.getText().toString());

 CountDownTimer bekle = new CountDownTimer(5000, 1000) {
                                                @Override
                                                public void onTick(long millis) {

                                                }
                                                @Override
                                                public void onFinish() {

                                                    Calendar c = Calendar.getInstance();
                                                    SimpleDateFormat dateformat = new SimpleDateFormat("dd-MMMM-yyyy HH:mm");
                                                    String datetime = dateformat.format(c.getTime());

                                                    list.add("Çalışma Süresi : " + calismapo +"  dk  "+"\n"+  "Mola Süresi : " + molapo+"  dk  " +"\n" + datetime);
                                                    arrayAdapter.notifyDataSetChanged();                                                                                                          SavePreferences("LISTS", task);

                                                }
                                            }.start();
                                        }
                                    }.start();
                                }
                            }.start();
                        }
                    }
                });
            }                                                                                                                                                                                                                  protected void SavePreferences(String key, String value) {

            SharedPreferences data = PreferenceManager.getDefaultSharedPreferences(this);
            SharedPreferences.Editor editor = data.edit();
            editor.putString(key, value);
            editor.commit();

        }

        protected void LoadPreferences(){
            SharedPreferences data = PreferenceManager.getDefaultSharedPreferences(this);
            String dataSet = data.getString("LISTS", "");

            list.add(dataSet);
            arrayAdapter.notifyDataSetChanged();

        }
        }