在拆分的面板中显示另一个类的数据

如何解决在拆分的面板中显示另一个类的数据

我想显示来自两个或多个mysql表的数据。好吧，两个表就足够了。

我发现以下代码可构建两个拆分面板。

import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GridLayout;
import javax.swing.*;


public class Combo extends javax.swing.JFrame{

   
    private final JSplitPane splitPane; 
    private final JPanel topPanel;    
    private final JPanel bottomPanel;  
    private final JScrollPane scrollPane; 
    private final JTextArea textArea;  
    private final JPanel inputPanel; 
    private final JButton button;  

    public Combo(){

        
        splitPane = new JSplitPane();
        topPanel = new JPanel();         
        bottomPanel = new JPanel();     
        scrollPane = new JScrollPane(); 
        textArea = new JTextArea();  

        inputPanel = new JPanel();
        button = new JButton("send");

        setPreferredSize(new Dimension(980,800));  
        getContentPane().setLayout(new GridLayout()); 
        getContentPane().add(splitPane);               

        splitPane.setOrientation(JSplitPane.VERTICAL_SPLIT);
        splitPane.setDividerLocation(400); 
        splitPane.setTopComponent(topPanel); 
        splitPane.setBottomComponent(bottomPanel); 

        /****Insert here data from another class *****/
        
        String workData = "2020 Agosto";
        NoFrame topSplit = new NoFrame(workData);
        topPanel.add(topSplit);
        
        bottomPanel.setLayout(new BoxLayout(bottomPanel,BoxLayout.Y_AXIS));  
        bottomPanel.add(scrollPane); 
        scrollPane.setViewportView(textArea); 
        bottomPanel.add(inputPanel); 

        
        inputPanel.setMaximumSize(new Dimension(Integer.MAX_VALUE,75)); 
        inputPanel.setLayout(new BoxLayout(inputPanel,BoxLayout.X_AXIS)); 

        
        inputPanel.add(button); 

        pack(); 
    }

    public static void main(String args[]){
        EventQueue.invokeLater(new Runnable(){
            @Override
            public void run(){
                new Combo().setVisible(true);
            }
        });
    }
}

我想将以下课程中的数据添加到topPanel

import java.awt.Color;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Vector;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.border.TitledBorder;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;

public class NoFrame  extends JPanel{
    
    public String foo;
    public JPanel newPanel;
    
public void dataPanel (String workData){ 
    JPanel newPanel = new JPanel();
    NoFrame zz = new NoFrame(workData);
    newPanel.add(zz);
    }
    
 public NoFrame(String workData)
    {
        
        String anno = workData.substring(0,4);
        String Mese =  workData.substring(5);
        int mese= Integer.parseInt(getMonthNbr(Mese));
        
        ArrayList columnNames = new ArrayList();
        
        ArrayList data = new ArrayList();

        //  Connect to an MySQL Database,run query,get result set
            [ usual stuff]
        try (Connection connection = 
            DriverManager.getConnection( url,userid,password );
            Statement stmt = connection.createStatement();
            ResultSet rs = stmt.executeQuery( sql )) {
            
            ResultSetMetaData md = rs.getMetaData();
            int columns = md.getColumnCount() - 2;

            //  Get column names
            for (int i = 1; i <= columns; i++) {
                String columnVal = md.getColumnName(i);
                columnNames.add(columnVal );}
            }

            //  Get row data
            while (rs.next())
            {
                ArrayList row = new ArrayList(columns);

                for (int i = 1; i <= columns; i++) {  
                    foo = null;
                    foo = rs.getString(i);
                    row.add(foo);
                }    
                data.add( row );
            }
        }
        catch (SQLException e) {JOptionPane.showMessageDialog(null,e.getMessage());}
        // Create Vectors and copy over elements from ArrayLists to them
        // Vector is deprecated but I am using them in this example to keep 
        // things simple - the best practice would be to create a custom defined
        // class which inherits from the AbstractTableModel class
        Vector columnNamesVector = new Vector();
        Vector dataVector = new Vector();

        for (int i = 0; i < data.size(); i++)
        {
            ArrayList subArray = (ArrayList)data.get(i);
            Vector subVector = new Vector();
            for (int j = 0; j < subArray.size(); j++) {
                subVector.add(subArray.get(j));
            }
            dataVector.add(subVector);
        }

        for (int i = 0; i < columnNames.size(); i++ ) {
            columnNamesVector.add(columnNames.get(i));
        }
            
            JTable table = new JTable(dataVector,columnNamesVector);
            table.setFont(new Font("Verdana",Font.PLAIN,11));
            table.setAutoResizeMode( JTable.AUTO_RESIZE_OFF );

        for (int column = 0; column < table.getColumnCount(); column++) {
    
            TableColumn tableColumn = table.getColumnModel().getColumn(column);
            int preferredWidth = tableColumn.getMinWidth();
            int maxWidth = tableColumn.getMaxWidth();
            table.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS);
            for (int row = 0; row < table.getRowCount(); row++) {
      
                TableCellRenderer cellRenderer = table.getCellRenderer(row,column);
                
                Component cell = table.prepareRenderer(cellRenderer,row,column);
        
                int width = cell.getPreferredSize().width + table.getIntercellSpacing().width;
                preferredWidth = Math.max(preferredWidth,width);

                if (preferredWidth >= maxWidth) {
                    preferredWidth = maxWidth;
                    break;
                }
            }
            tableColumn.setPreferredWidth( preferredWidth);
            
            CustomRenderer renderer = new CustomRenderer();
            renderer.setHorizontalAlignment(JLabel.CENTER);
            for (int col = 0; col < table.getColumnCount(); col++) {
            table.getColumnModel().getColumn(col).setCellRenderer(renderer);
            }
        }    
            
        
       
            JScrollPane scrollPane = new JScrollPane( table,JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
            scrollPane.setBorder(BorderFactory.createTitledBorder (BorderFactory.createEtchedBorder (),"Table allhour",TitledBorder.CENTER,TitledBorder.TOP,new Font("Verdana",Font.BOLD,14),Color.blue)); 
            
            JPanel panel = new JPanel();
            scrollPane.add(panel);         
            newPanel.add(table);
           
            
              
}
 
public void jButton1ActionPerformed(ActionEvent evt) { }
    
public String getMonthNbr(String inputMese) {
[...]
     
     return cmese;
}

}

NoFrame已正确执行[newPanel.add（table）包含整个数据]，但是Combo的返回仅显示两个拆分的面板和按钮。 topSplit包含newPanel = 空

有什么建议吗？

拍子