Java JTable错误复制行

Question

Good day! There is a problem in downloaded program. You can copy a row by clicking on it by right mouse button, but after that when you change data in one cell data will be changed in every cell in column. Please, help me to understand, what I've missed.

import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.awt.BorderLayout;


import javax.swing.JFrame;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.table.AbstractTableModel;


public class Main extends JFrame{

    JMenuItem obrc;
    JTable table;
    DataModel tm;
    JScrollPane scrollTable;

    Main() {
         super("Example JTable");
         Container c = getContentPane();
         ArrayList<String> columnNames = new ArrayList<String>();
         columnNames.add("Type"); columnNames.add("Sort"); columnNames.add("Thickness"); columnNames.add("Width"); 
         tm = new DataModel(columnNames);
         table = new JTable(tm);
         c.add(new JScrollPane(table), BorderLayout.CENTER);
         setSize(400, 300);
         setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         setVisible(true);


        table.getColumnModel().getColumn(0).setPreferredWidth(40);
        table.getColumnModel().getColumn(1).setPreferredWidth(40);
        table.addMouseListener(new MouseAdapter(){
            public void mouseClicked(MouseEvent event) {
                if (SwingUtilities.isRightMouseButton(event)) {
                    JPopupMenu obrcd = new JPopupMenu();
                    obrc = new JMenuItem("Copy");
                    obrc.addActionListener(new MenuListener());
                    obrcd.add(obrc); 
                    obrcd.show(c, event.getX(), event.getY()); 
                }
            }
        });
    }

    public class MenuListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            int[] nums = table.getSelectedRows();
            if (nums.length != 0) {
                if (e.getSource() == obrc) {
                ArrayList<Object[]> list = tm.getRows(nums);
                tm.addRows(list);
                }

                else JOptionPane.showMessageDialog(null, 
                    "Select at least one row", "Warning", JOptionPane.ERROR_MESSAGE);
            }
        }
    }   


        public static void main(String[] args) {
            // TODO Auto-generated method stub
            SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    new Main();

                }

            });
        }

        class DataModel extends AbstractTableModel{
              ArrayList<Object[]> data = new ArrayList<Object[]>();
              ArrayList<String> columnNames = new ArrayList<String>();

            public DataModel(ArrayList<String> cNames){
                super();
                columnNames = cNames;
                Object[] dat = new Object[4];
                dat[0] = "board";
                dat[1] = "1";
                dat[2] = "25";
                dat[3] = "150";
                data.add(dat);
            }

            public boolean isCellEditable(int rowIndex, int columnIndex)
            {
              return true;
            }

            public Object getValueAt(int rowIndex, int columnIndex){ 
                Object[] row = data.get(rowIndex);

                return row[columnIndex];
            };

            public void setValueAt(Object newValue, int rowIndex, int columnIndex){
                data.get(rowIndex)[columnIndex] = newValue;
                fireTableDataChanged();

            }

            public int getRowCount()
            {
                return data.size();
            };

            public int getColumnCount()
            {
                return columnNames.size();
            };
            public String getColumnName(int column)
            {
                    return columnNames.get(column);
            }

            public ArrayList<Object[]> getRows(int[] nums) {
                ArrayList<Object[]> newdata = new ArrayList<Object[]>();
                for (int i = 0; i < nums.length; i++) {
                    newdata.add(data.get(nums[i]));
                }
                return newdata;
            }

            public void addRows (ArrayList<Object[]> rows) {
                for (int i = 0; i < rows.size(); i++) data.add(rows.get(i));
                fireTableDataChanged();
            }

        }
}

Answer 1

Problem when you are adding new rows

    public void addRows (ArrayList<Object[]> rows) {
        for (int i = 0; i < rows.size(); i++) data.add(rows.get(i));
        fireTableDataChanged();
    }

Your copied row(s) will point to same object(s) with selected row(s). You need clone to new object:

public void addRows (ArrayList<Object[]> rows) {
    for (int i = 0; i < rows.size(); i++) {
        Object[] clone = rows.get(i).clone();
        data.add(clone);
    }
    fireTableDataChanged();
}