将数据保存在 HashMap 中

Question

我正在使用一个接口循环接收数据，该接口从循环中给我 JSONObject 和“i”。 每次我收到一个不同的：

{
    "Id_temp": "1",
    "temperatura": "20",
    "Insertado_temp": "2016-08-16 12:30:29"
}

而且我需要将所有 JsonObjects 保存在一个 HashMap 中-但是每次尝试时，来自接口的数据都会覆盖它，然后只有一个对象“最后一个”在 Map 中，而其他对象会被删除。

我非常感谢如何在我的代码中实现它的示例。 我在这里写代码。 作为 HashMap 的键值，我需要在“Id”中接收到的参数“Id_temp”

public class GraficaBarometro extends AppCompatActivity implements OnLoopjCompletedBarometro {

private DrawerLayout drawerLayout;

private OnLoopjCompletedBarometro loopjListener;

// Progress Dialog Object
ProgressDialog prgDialog;
// Error Msg TextView Object
TextView errorMsg;
// Email Edit View Object

private String temeperatura;

private Timestamp timestamp;


List<Entry> presiones = new ArrayList<>();
List<Entry> temperaturas = new ArrayList<>();
List<String> dates = new ArrayList<>();


LineChart mChart;

LoopjTasksBarometro loopjTasks;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.actividad_grafica_barometro);
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
    String idObjeto = (String) getIntent().getExtras().getSerializable("IdentidadEnviada");

    loopjTasks = new LoopjTasksBarometro(this, this);
    loopjTasks.CaptarParametros(idObjeto);


    mChart = (LineChart) findViewById(R.id.chartbarometro);

    int currentTime = (int) System.currentTimeMillis();
    timestamp = new Timestamp(currentTime);

    // no description text
    mChart.setDescription("");
    mChart.setNoDataTextDescription("You need to provide data for the chart.");

    // enable touch gestures
    mChart.setTouchEnabled(true);

    mChart.setDragDecelerationFrictionCoef(0.9f);

    // enable scaling and dragging
    mChart.setDragEnabled(true);
    mChart.setScaleEnabled(true);
    mChart.setDrawGridBackground(true);
    mChart.setHighlightPerDragEnabled(true);

    // limit the number of visible entries
    mChart.setVisibleXRangeMaximum(5);

    // if disabled, scaling can be done on x- and y-axis separately
    mChart.setPinchZoom(true);

    // set an alternative background color
    mChart.setBackgroundColor(Color.LTGRAY);


    mChart.animateX(2500);

// to draw X-axis for our graph


    XAxis xAxis = mChart.getXAxis();
    xAxis.setTextSize(11f);
    xAxis.setEnabled(true);
    xAxis.setPosition(com.github.mikephil.charting.components.XAxis.XAxisPosition.BOTTOM);
    //xAxis.setAxisMaxValue(125f);
    xAxis.setAxisMinValue(0f);
    xAxis.setTextColor(Color.DKGRAY);
    xAxis.setDrawGridLines(false);
    xAxis.setDrawAxisLine(true);

    // to draw axis line

    //modify leftYaxis range similarly others
    YAxis leftAxis = mChart.getAxisLeft();
    leftAxis.setTextColor(ColorTemplate.getHoloBlue());
    leftAxis.setAxisMaxValue(50f);
    leftAxis.setAxisMinValue(10f);
    leftAxis.setDrawGridLines(false);
    leftAxis.setGranularityEnabled(true);


    YAxis rightAxis = mChart.getAxisRight();
    rightAxis.setTextColor(Color.RED);
    rightAxis.setAxisMaxValue(50f);
    rightAxis.setAxisMinValue(10f);
    rightAxis.setDrawGridLines(false);
    rightAxis.setDrawZeroLine(false);
    rightAxis.setGranularityEnabled(false);


}


private void agregarToolbar() {
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    final ActionBar ab = getSupportActionBar();
    if (ab != null) {
        // Poner ícono del drawer toggle
        ab.setHomeAsUpIndicator(R.drawable.drawer_toggle);
        ab.setDisplayHomeAsUpEnabled(true);
    }

}

private void prepararDrawer(NavigationView navigationView) {
    navigationView.setNavigationItemSelectedListener(
            new NavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(MenuItem menuItem) {
                    menuItem.setChecked(true);
                    seleccionarItem(menuItem);
                    drawerLayout.closeDrawers();
                    return true;
                }
            });

}


private void seleccionarItem(MenuItem itemDrawer) {
    Fragment fragmentoGenerico = null;

    FragmentManager fragmentManager = getSupportFragmentManager();


    switch (itemDrawer.getItemId()) {
      /*
       case R.id.item_inicio:
            fragmentoGenerico = new FragmentoInicio();
            break;
*/
        case R.id.item_web:

            startActivity(new Intent(this, WebOficial.class));
            break;

        //fragmentoGenerico = new BlankFragment();


        case R.id.item_categorias:
            startActivity(new Intent(this, ActividadListaObjeto.class));
            break;

        case R.id.item_acceso:
            startActivity(new Intent(this, MainActivity.class));
            break;
    }
    if (fragmentoGenerico != null) {
        fragmentManager
                .beginTransaction()
                .replace(R.id.contenido_principal, fragmentoGenerico)
                .commit();

        /*
        if(fragmentTransaction) {
            getSupportFragmentManager().beginTransaction()
                    .replace(R.id.content_frame, fragment)
                    .commit();
           */

    }

    // Setear titulo actual
    setTitle(itemDrawer.getTitle());
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_actividad_principal, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            drawerLayout.openDrawer(GravityCompat.START);
            return true;
    }
    return super.onOptionsItemSelected(item);
}
/*
public String parseHours(long millis){
    String currentDate = new SimpleDateFormat("hh:mm").format(new Date(millis));
    Log.i(UtilitiesGlobal.TAG, "parseHours: " + currentDate);
    return currentDate;
}
*/

private void setData() {

linLineDataSet set1, set2;

    // create a dataset and give it a type
    //modifications with colour and stuf
    set1 = new LineDataSet(temperaturas, "temperatura");

    set1.setAxisDependency(YAxis.AxisDependency.LEFT);
    set1.setColor(ColorTemplate.getHoloBlue());
    set1.setCircleColor(Color.WHITE);
    set1.setLineWidth(2f);
    set1.setCircleRadius(2f);
    set1.setFillAlpha(65);
    set1.setFillColor(ColorTemplate.getHoloBlue());
    set1.setHighLightColor(Color.rgb(244, 117, 117));
    set1.setDrawCircleHole(false);


    //set1.setFillFormatter(new MyFillFormatter(0f));
    //set1.setDrawHorizontalHighlightIndicator(false);
    //set1.setVisible(false);
    //set1.setCircleHoleColor(Color.WHITE);

    // create a dataset and give it a type
    // similar above
    set2 = new LineDataSet(presiones, "presion");
    set2.setAxisDependency(YAxis.AxisDependency.RIGHT);
    set2.setColor(Color.RED);
    set2.setCircleColor(Color.WHITE);
    set2.setLineWidth(2f);
    set2.setCircleRadius(2f);
    set2.setFillAlpha(65);
    set2.setFillColor(Color.RED);
    set2.setDrawCircleHole(false);
    set2.setHighLightColor(Color.rgb(244, 117, 117));
    //set2.setFillFormatter(new MyFillFormatter(900f));


    mChart.getXAxis().setValueFormatter(new AxisValueFormatter() {
        @Override
        public String getFormattedValue(float value, AxisBase axis) {
            return dates.get((int) value);
        }

        @Override
        public int getDecimalDigits() {
            return 0;
        }
    });

    ArrayList<ILineDataSet> dataSets = new ArrayList<ILineDataSet>();
    dataSets.add(set1); // add the datasets
    dataSets.add(set2);


    // create a data object with the datasets
    LineData data = new LineData(dataSets);
    data.setValueTextColor(Color.BLACK);
    data.setValueTextSize(9f);

    // set data
    Log.i("Lists Sizedata", temperaturas.size() + " and " + presiones.size());
    mChart.setData(data);
    // move to the latest entry
    mChart.moveViewToX(data.getEntryCount());


}

@Override
public void onLoopjTaskCompletedBarometro(JSONObject parametrosdht11, int i) {


    String temperatura = null;
    String presion = null;
    String fecha = null;
    String Id = null;
    String altitud = null;



    try {

        Id = parametrosdht11.getString("Id_temp");
        temperatura = parametrosdht11.getString("temperatura");
        fecha = parametrosdht11.getString("Insertado_temp");
        presion = parametrosdht11.getString("presion");
        altitud = parametrosdht11.getString("altitud");


    } catch (JSONException e) {
        e.printStackTrace();
    }




    temperaturas.add(new Entry(Float.valueOf(i), Float.valueOf(temperatura)));
    presiones.add(new Entry(Float.valueOf(i), Float.valueOf(presion)));
    dates.add(fecha); // reduce the string to just 12:13 etc





    //rrefresh we don't need to refresh since we are setting data after completing task
    mChart.notifyDataSetChanged();
    // mChart.setVisibleXRangeMaximum(12);

    //Log.i(UtilitiesGlobal.TAG, "onSuccess: loopj " + usuarioiJSONbject);
    Log.i(UtilitiesGlobal.TAG, "onSuccess: loopj " + "temperatura: " + temperatura + " presion: "
            + presion + " Fecha Inserción: " + fecha);

}



@Override
public void onLoopCompleteBarometro() {
    setData();
    // it takes time to recieve time. so we set the map after loop is complete okay?
    //mChart.setVisibleXRangeMaximum(5);
}

现在这里是带有哈希码和 equals 方法的类

public class ParametrosBarometro {
int i;
String Id_temperatura;
String temperatura;
String fecha_temperatura;
String presion;
String altitud;


public ParametrosBarometro(String Id_temperatura, String temperatura, String fecha_temperatura, String presion, String altitud) {

    this.Id_temperatura = Id_temperatura;
    this.temperatura = temperatura;
    this.fecha_temperatura = fecha_temperatura;
    this.presion = presion;
    this.altitud = altitud;

}

@Override
public boolean equals(Object o) {
    if (o instanceof ParametrosBarometro) {
        ParametrosBarometro p = (ParametrosBarometro) o;
        return this.Id_temperatura.equals(p.Id_temperatura);
    } else {
        return false;
    }

}

@Override
public int hashCode() {
    return this.Id_temperatura.length() * this.Id_temperatura.length();
}

}

Answer 1

我正在使用一个接口循环接收数据，该接口从循环中给我 JSONObject 和“i”。 [...] 作为 HashMap 的键值，我需要在“Id”中接收到的参数“Id_temp”。

好的。 就这么简单：

private final Map<Integer, MyBean> map=new HashMap<Integer, MyBean>();

private void createAndStoreObject(JsonObject json, int i)
    throws ParseException
{
    SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    MyBean myBean=new MyBean(json.getInt("Id_temp"), json.getInt("temperatura"), format.parse(json.getString("Insertado_temp")));
    this.map.put(myBean.getId(), myBean);
}

class MyBean
{
    private final int id;

    private final int temperature;

    private final Date insertionDate;

    public MyBean(int id, int temperature, Date insertionDate)
    {
        super();
        this.id=id;
        this.temperature=temperature;
        this.insertionDate=insertionDate;
    }

    public int getId()
    {
        return this.id;
    }

    // ... getters ...
}

如您所见，作为 Integer 的关键（它是与 Java 运行时环境捆绑在一起的类），不需要覆盖hashCode或equals方法（Integer 已经有了它们）。