java – JTable中Date上的无效排序

发布时间：2020-12-14 23:56:53 所属栏目：Java 来源：网络整理

导读：请看下面的代码 import java.awt.*;import java.awt.event.*;import java.text.NumberFormat;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.*;import java.util.logging.Level;import java.util.logging.Logger;impo

请看下面的代码

import java.awt.*;
import java.awt.event.*;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.table.*;

public class TableBasic extends JFrame
{
    public TableBasic()
    {

        String[] columnNames = {"Date","String","Long","Boolean"};
        Object[][] data =
        {
            {getJavaDate("13-11-2020"),"A",new Long(1),Boolean.TRUE },{getJavaDate("13-11-2018"),"B",new Long(2),Boolean.FALSE},{getJavaDate("12-11-2015"),"C",new Long(9),"D",new Long(4),Boolean.FALSE}
        };

        final JTable table = new JTable(data,columnNames);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        table.setAutoCreateRowSorter(true);
        table.getColumnModel().getColumn(0).setCellRenderer(tableCellRenderer);

        // DefaultRowSorter has the sort() method
        DefaultRowSorter sorter = ((DefaultRowSorter)table.getRowSorter()); 
        ArrayList list = new ArrayList();
        list.add( new RowSorter.SortKey(0,SortOrder.DESCENDING) );
        sorter.setSortKeys(list);
        sorter.sort();

        JScrollPane scrollPane = new JScrollPane( table );
        getContentPane().add( scrollPane );
    }

    private TableCellRenderer tableCellRenderer = new DefaultTableCellRenderer() 
    {

        SimpleDateFormat f = new SimpleDateFormat("dd-MM-yyyy");

        public Component getTableCellRendererComponent(JTable table,Object value,boolean isSelected,boolean hasFocus,int row,int column) 
        {
            if( value instanceof Date) 
            {
                value = f.format(value);
            }
            return super.getTableCellRendererComponent(table,value,isSelected,hasFocus,row,column);
        }
    };

    private Date getJavaDate(String s)
    {
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
            Date d = sdf.parse(s);
             return d;

        } catch (ParseException ex) {
            Logger.getLogger(TableBasic.class.getName()).log(Level.SEVERE,null,ex);
            return null;
        }
    }



    public static void main(String[] args)
    {
        TableBasic frame = new TableBasic();
        frame.setDefaultCloSEOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setLocationRelativeTo( null );
        frame.setVisible(true);
    }
}

现在,尝试使用Date字段对其进行排序.它以无效的方式排序！以下是结果！

为什么会这样发生？我甚至用过细胞渲染！

解决方法

@Sciper不是一个回答,但我无法抗拒,因为你的代码非常复杂,设计错误,错过了需要的轻量级…

缺少的关键元素是覆盖TableModel.getColumnClass(),这对于表排序功能至关重要

import java.awt.*;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import static javax.swing.JFrame.EXIT_ON_CLOSE;
import javax.swing.table.*;

public class TableBasic {

    private JFrame frame = new JFrame();
    private  String[] columnNames = {"Date","Boolean"};
    private Object[][] data = {
        {getJavaDate("13-11-2020"),new Double(1),Boolean.TRUE},new Double(2),new Double(9),new Double(4),Boolean.FALSE}
    };
    private DefaultTableModel model = new DefaultTableModel(data,columnNames) {
        @Override
        public Class<?> getColumnClass(int column) {
            return getValueAt(0,column).getClass();
        }
    };
    private JTable table = new JTable(model);
    private JScrollPane scrollPane = new JScrollPane(table);
    private static final DateFormat DATE_FORMAT = new SimpleDateFormat("dd/MM/yyyy");

    public TableBasic() {
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        table.setAutoCreateRowSorter(true);
        setRenderers();
        // DefaultRowSorter has the sort() method
        table.getRowSorter().toggleSortOrder(0);
        frame.add(scrollPane);
        frame.setDefaultCloSEOperation(EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    private void setRenderers() {
        //TableColumnModel m = table.getColumnModel();
        //"Integer","Interger","Double","Boolean","Date"
        table.setDefaultRenderer(Date.class,new DateRenderer());
    }

    private Date getJavaDate(String s) {
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
            Date d = sdf.parse(s);
            return d;

        } catch (ParseException ex) {
            Logger.getLogger(TableBasic.class.getName()).log(Level.SEVERE,ex);
            return null;
        }
    }

    public static void main(String[] args) {

        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                TableBasic frame = new TableBasic();
            }
        });
    }

    private class DateRenderer extends DefaultTableCellRenderer {

        private static final long serialVersionUID = 1L;

        @Override
        public Component getTableCellRendererComponent(JTable table,int column) {
            super.getTableCellRendererComponent(table,column);
            if (!(value instanceof Date)) {
                return this;
            }
            setText(DATE_FORMAT.format((Date) value));
            return this;
        }
    }
}

（编辑：李大同）

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