java将firebase数据放在JTable中

Question

我正在努力将一些firebase数据放入JavaSwing中的jtable中。 如图所示，我已经能够从firebase检索数据，但由于某些原因，数据不会显示在JTable字段中（表1） 我看起来像getID（），getName（）。。。方法没有得到任何值，因为我试图打印第[I]行以查看是否有任何值

There is a screenshot of the actual program

你们谁能告诉我是什么问题吗

addNewCaseButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                database = FirebaseDatabase.getInstance();
                ref = database.getReference("NewCases");
                ref.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        System.out.println(dataSnapshot.getValue());

                        ArrayList<Object[]> myList = new ArrayList<>();
                        DefaultTableModel tableModel = (DefaultTableModel) table1.getModel();
                        tableModel.addColumn("ID");
                        tableModel.addColumn("Name");
                        tableModel.addColumn("Age");
                        tableModel.addColumn("City");
                        tableModel.addColumn("TimeStamp");
                        tableModel.addColumn("Disease");
                        tableModel.addColumn("Risk");
                        Object[] row = new Object[6];
                        tableModel.setNumRows(0);
                        myList.clear();

                        CasesList casesList = new CasesList();

              for (DataSnapshot ds : dataSnapshot.getChildren()){
                            

               casesList.setID((Integer)ds.child("ID").getValue());
                      
               casesList.setName(ds.child("Name").getValue().toString());
                            
               casesList.setAge((Integer)ds.child("Age").getValue());
                            
               casesList.setCity(ds.child("City").getValue().toString());
                            
          
         casesList.setTimeStamp(ds.child("TimeStamp").getValue().toString());
                            
         casesList.setDisease(ds.child("Disease").getValue().toString());
                            
         casesList.setRisk(ds.child("Risk").getValue().toString());
//       myList.add(ds.getKey());

                            row[0] = casesList.getID();
                            row[1] = casesList.getName();
                            row[2] = casesList.getAge();
                            row[3] = casesList.getCity();
                            row[4] = casesList.getTimeStamp();
                            row[5] = casesList.getDisease();
                            row[6] = casesList.getRisk();
                            myList.add(row);

                            System.out.println(myList);
                            tableModel.addRow(row);
                        }
                        table1.setModel(tableModel);

提前谢谢

Answer 1

您是否用这样的行定义了表列

DefaultTableModel tableModel = new DefaultTableModel();
tableModel.addColumn("ID");
tableModel.addColumn("Name");
tableModel.addColumn("Age");

此外，方法setModel应该在for之后调用：

  for... {
      //add row to tableModel 
  }
  table1.setModel(tableModel);

编辑： 通过更详细的分析，我还验证了您有7个字段，但您的数组只有6个字段的空间。在这一行中row [6] = casesList.getRisk ();在运行时抛出一个异常。扩展阵列的大小以解决此问题。 Object[] row = new Object[7];

要显示列名，可以方便地将表格添加到滚动面板中

JScrollPane scrollPane = new JScrollPane(table1);
frame.getContentPane().add(scrollPane);

这对我很有用：

ArrayList<Object[]> myList = new ArrayList<>();
DefaultTableModel tableModel = (DefaultTableModel) table1.getModel();
tableModel.addColumn("ID");
tableModel.addColumn("Name");
tableModel.addColumn("Age");
tableModel.addColumn("City");
tableModel.addColumn("TimeStamp");
tableModel.addColumn("Disease");
tableModel.addColumn("Risk");
Object[] row = new Object[7];
tableModel.setNumRows(0);
myList.clear();


for (DataSnapshot ds : dataSnapshot.getChildren()) {
    
    CasesList casesList = new CasesList();
    casesList.setID((Integer) ds.child("ID").getValue());
    casesList.setName(ds.child("Name").getValue().toString());
    casesList.setAge((Integer) ds.child("Age").getValue());
    casesList.setCity(ds.child("City").getValue().toString());
    casesList.setTimeStamp(ds.child("TimeStamp").getValue().toString());
    casesList.setDisease(ds.child("Disease").getValue().toString());
    casesList.setRisk(ds.child("Risk").getValue().toString());

    row[0] = casesList.getID();
    row[1] = casesList.getName();
    row[2] = casesList.getAge();
    row[3] = casesList.getCity();
    row[4] = casesList.getTimeStamp();
    row[5] = casesList.getDisease();
    row[6] = casesList.getRisk();
    
    myList.add(row);

    System.out.println(myList);
    tableModel.addRow(row);
    
}
table1.setModel(tableModel);