java - 为什么我的 JTable 对整数列的排序不正确？

Question

我有一个使用 DefaultTableModel 的 JTable，我允许在用户单击列标题时进行排序。但是，当用户单击具有整数类型数据的列的标题时，它不会正确排序。看起来它是按 String 而不是整数类型排序。

这是我实际将数据添加到表中的代码部分:

        DefaultTableModel aModel = (DefaultTableModel) mainView.logEntryTable.getModel();
                    ResultSetMetaData rsmd;             try {
            mainView.logEntriesTableModel.setRowCount(0);
            rsmd = rs.getMetaData();

            int colNo = rsmd.getColumnCount();
            while(rs.next()){
                Object[] objects = new Object[colNo];
                for(int i=0;i<colNo;i++){
                    objects[i]=rs.getObject(i+1);
                }
                aModel.addRow(objects);
                count++;
            }
            mainView.logEntryTable.setModel(aModel);
            mainView.logEntryTable.getColumnModel().getColumn(0).setMaxWidth(80);

所以我试图重写那个方法，结果是这样的:

            @Override
            public Class<?> getColumnClass(int columnIndex){
                if( columnIndex == 0){
                    // Return the column class for the integer column
                }else{
                    // Return the column class like we normally would have if we didn't override this method
                }

                return null;
            }
        };

我以前从未覆盖过它，我不太确定它期望我在这里做什么。

Answer 1

试试这个小例子。

更好的方法

正如 Kleopatra 所建议的那样，为每个列定义一个相关的列类就足以使数据正确排序。

import javax.swing.*;
import javax.swing.table.*;
import java.util.Comparator;

class TableSorting {
    public static void main(String[] args) {
        Object[][] data = {
            {new Integer(1), "Don't Let Go", new Integer(179)},
            {new Integer(2), "Photograph", new Integer(29)},
            {new Integer(3), "Hash Pipe", new Integer(186)},
            {new Integer(4), "Island In The Sun", new Integer(200)},
            {new Integer(5), "Crab", new Integer(154)},
            {new Integer(6), "Knock-Down Drag-Out", new Integer(128)},
            {new Integer(7), "Smile", new Integer(158)},
            {new Integer(8), "Simple Pages", new Integer(176)},
            {new Integer(9), "Glorious Day", new Integer(160)},
            {new Integer(10), "O Girlfriend", new Integer(230)}
        };
        Object[] columns = {"Track #", "Title", "Length"};
        DefaultTableModel model = new DefaultTableModel(data,columns) {
            @Override
            public Class getColumnClass(int column) {
                switch (column) {
                    case 0:
                        return Integer.class;
                    case 1:
                        return String.class;
                    case 2:
                        return Integer.class;
                    default:
                        return String.class;
                }
            }
        };
        JTable table = new JTable(model);
        JScrollPane scroll = new JScrollPane(table);
        table.setAutoCreateRowSorter(true);
        JOptionPane.showMessageDialog(null, scroll);
    }
}

原始，使用比较器

import javax.swing.*;
import javax.swing.table.*;
import java.util.Comparator;

class TableSorting {
    public static void main(String[] args) {
        Object[][] data = {
            {new Integer(1), "Don't Let Go", new Integer(179)},
            {new Integer(2), "Photograph", new Integer(29)},
            {new Integer(3), "Hash Pipe", new Integer(186)},
            {new Integer(4), "Island In The Sun", new Integer(200)},
            {new Integer(5), "Crab", new Integer(154)},
            {new Integer(6), "Knock-Down Drag-Out", new Integer(128)},
            {new Integer(7), "Smile", new Integer(158)},
            {new Integer(8), "Simple Pages", new Integer(176)},
            {new Integer(9), "Glorious Day", new Integer(160)},
            {new Integer(10), "O Girlfriend", new Integer(230)}
        };
        Object[] columns = {"Track #", "Title", "Length"};
        JTable table = new JTable(data, columns);
        JScrollPane scroll = new JScrollPane(table);
        DefaultTableModel model = new DefaultTableModel(data,columns);
        TableRowSorter trs = new TableRowSorter(model);

        class IntComparator implements Comparator {
            public int compare(Object o1, Object o2) {
                Integer int1 = (Integer)o1;
                Integer int2 = (Integer)o2;
                return int1.compareTo(int2);
            }

            public boolean equals(Object o2) {
                return this.equals(o2);
            }
        }

        trs.setComparator(0, new IntComparator());

        table.setRowSorter(trs);

        scroll = new JScrollPane(table);
        table.setAutoCreateRowSorter(false);
        JOptionPane.showMessageDialog(null, scroll);
    }
}