Question

目前我有一个DerbyDB和一个带有JTable的UI。现在我也有一堆课程，但我需要帮助的课程是SensorDBConnection和myUI。 myUI是我的JTable的地方，我想要做的是从查询中更新我的JTable，该查询位于我的SensorDBConnection

以下是我SensorDBConnection的代码段，因为它正在执行System.outs

DefaultTableModel model;//Confused
    model = new DefaultTableModel(); //Confused
    jTable1 = new JTable(model);//Confused 

    model.addColumn("TIME");
    model.addColumn("SENSORID");
    model.addColumn("TEMP");
    model.addColumn("HUM");
    model.addColumn("LIGHT");
    model.addColumn("VOLTAGE");

        while(results.next())
        {
            time = results.getInt(1);
            id = results.getInt(2);
            temp = results.getInt(3);
            hum = results.getInt(4);
            light = results.getInt(5);
            voltage = results.getInt(6);
            model.addRow(new Object[]{time,id,temp,hum,light,voltage});
            Sensor sens = new Sensor(id, temp, hum, light, voltage);
            sensors.add(sens);               
            //System.out.println(sens);
        }

        results.close();
        stmt.close();

基本上我现在正在做的是查询我的数据，然后尝试将它推送到位于我其他类的JTabel上，我不知道如何在它们之间创建链接..

Answer 1

首先将UI与数据管理分开。不要让SensorDBConnection返回TableModel，而是让它返回构建数据模型所需的数据......

例如......

public class SensorDBConnection extends ... {
    public List<Sensor> loadData() {
        List<Sensor> sensors = new ArrayList<>(25);
        try {
            //...
            while(results.next())
            {
                time = results.getInt(1);
                id = results.getInt(2);
                temp = results.getInt(3);
                hum = results.getInt(4);
                light = results.getInt(5);
                voltage = results.getInt(6);
                model.addRow(new Object[]{time,id,temp,hum,light,voltage});
                Sensor sens = new Sensor(id, temp, hum, light, voltage);
                sensors.add(sens);               
            }
        } finally {
            try {
                results.close();
            } catch (Exception exp) {
            }
            try {
                stmt.close();  
            } catch (Exception exp) {
            }
        }
        return sensors;
    }
}

然后，在MyUI中，您只需请求传感器数据并构建您的TableModel。为了让您的生活更简单，请创建一个知道如何处理TableModel的自定义Sensor ...

public class SensorTableModel extends AbstractTableModel {

    protected static final String[] COLUMN_NAMES = {
        "TIME",
        "SENSORID",
        "TEMP",
        "HUM",
        "LIGHT",
        "VOLTAGE"
    };

    private List<Sensor> sensors;

    public SensorTableModel(List<Sensor> sensors) {
        this.sensors = sensors;
    }

    @Override
    public String getColumnName(int column) {
        return COLUMN_NAMES[column];
    }

    @Override
    public int getRowCount() {
        return sensors.size();
    }

    @Override
    public int getColumnCount() {
        return COLUMN_NAMES.length;
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        Sensor sensor = sensors.get(rowIndex);
        Object value = null;
        switch (columnIndex) {
            case 0:
                value = sensor.getTime();
                break;
            case 1:
                value = sensor.getID();
                break;
            case 2:
                value = sensor.getTemp();
                break;
            case 3:
                value = sensor.getHum();
                break;
            case 4:
                value = sensor.getLight();
                break;
            case 5:
                value = sensor.getVoltage();
                break;
        }
        return value;
    }
}

然后只需在loadData类的SensorDBConnection中调用MyUI方法，只需创建一个已经拥有的TableModel and apply it to the JTable`实例的实例...

 public class MyUI extends ... {
     private JTable table;
     private SensorDBConnection sensor;
     //...
     protected void loadTableContents() {
         TableModel model = null;
         try {
            model = new SensorTableModel(sensor.loadData());
         } catch (SQLException exp) {
             // Handle exception
         }
         table.setModel(model);
     }
 }

例如......

Answer 2

如果我正确理解了您的问题，您应该能够在myUI中创建SensorDBConnection的实例。这样你就可以在myUI中调用SensorDBConnection的方法，查询等等。

Answer 3

我会创建自己的TableModel子类，该子类特定于返回的数据。然后，一旦将TableModel中的数据设置为新数据，请调用fireTableDataChanged（）。

从查询更新JTable

3 个答案: