可拖拽表格的swing实现（通过拖拽表格的行，实现交换行位置的交换）

swing里的table可以通过setUI(？ extends  BasicTableUI )这个方法来实现对表的外观的一些控制，如下代码实现了简单的例子：

1.测试类：

import java.awt.Dimension;import java.awt.Toolkit;import javax.swing.JFrame;import javax.swing.JScrollPane;public class DragTableTest extends JFrame {/** * table拖拽交换数据样例 */private static final long serialVersionUID = 1L;private DragTable table= null;String [] header = {"ID","name","score"};Object [][] data  = {{1,"贾巴尔",38387},{2,"马龙",36928},{3,"kobe",32331},{4,"jordan",32292},{5,"张伯伦",31419}};public DragTableTest () {initView();setLocalCenter();}public static void main(String[] args) {DragTableTest tst = new DragTableTest();tst.setVisible(true);}private void initView (){this.setSize(new Dimension(400,400));this.setTitle("可拖拽换行table:");JScrollPane  pan = new JScrollPane(getTable());this.getContentPane().add(pan);this.setDefaultCloseOperation(EXIT_ON_CLOSE);}private DragTable getTable(){if(table == null){table = new DragTable();table.setModel(new DragTableModel(data,header));table.setUI(new DragDropRowTableUI());}return table;}/** * 界面居中 */private void setLocalCenter(){Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();int screenWidth = screenSize.width;int screenHight = screenSize.height;this.setLocation((screenWidth - this.getWidth()) / 2,(screenHight - this.getHeight()) / 2);}}2.在这里自定义的tableUI如下：import java.awt.Graphics;import java.awt.Rectangle;import java.awt.event.MouseEvent;import javax.swing.JComponent;import javax.swing.event.MouseInputListener;import javax.swing.plaf.basic.BasicTableUI;import javax.swing.table.TableModel;public class DragDropRowTableUI extends BasicTableUI { /**  * @author zhen.p  */ private boolean draggingRow = false; private int startDragPoint; private int dyOffset; TableModel model=null;    protected MouseInputListener createMouseInputListener() {        return new DragDropRowMouseInputHandler();    }    public void paint(Graphics g, JComponent c) {super.paint(g, c);if (draggingRow) {g.setColor(table.getParent().getBackground());Rectangle cellRect = table.getCellRect(table.getSelectedRow(), 0,false);g.copyArea(cellRect.x, cellRect.y, table.getWidth(),table.getRowHeight(), cellRect.x, dyOffset);if (dyOffset < 0) {g.fillRect(cellRect.x, cellRect.y+ (table.getRowHeight() + dyOffset), table.getWidth(),(dyOffset * -1));} else {g.fillRect(cellRect.x, cellRect.y, table.getWidth(), dyOffset);}}    }    class DragDropRowMouseInputHandler extends MouseInputHandler {public void mousePressed(MouseEvent e) {super.mousePressed(e);startDragPoint = (int) e.getPoint().getY();}public void mouseDragged(MouseEvent e) {int fromRow = table.getSelectedRow();if (fromRow >= 0) {draggingRow = true;int rowHeight = table.getRowHeight();int middleOfSelectedRow = (rowHeight * fromRow)+ (rowHeight / 2);int toRow = -1;int yMousePoint = (int) e.getPoint().getY();if (yMousePoint < (middleOfSelectedRow - rowHeight)) {// Move row uptoRow = fromRow - 1;} else if (yMousePoint > (middleOfSelectedRow + rowHeight)) {// Move row downtoRow = fromRow + 1;}if (toRow >= 0 && toRow < table.getRowCount()) {model = table.getModel();if(model instanceof DragTableModel) {

//用于交换tableModel中数据的顺序，以供拖拽至后数据交换位置显示Object[][] data = ((DragTableModel) model).getData();Object[][] listresult = swapObjectList(data, fromRow, toRow);((DragTableModel) model).setData(listresult);}table.setRowSelectionInterval(toRow, toRow);startDragPoint = yMousePoint;}dyOffset = (startDragPoint - yMousePoint) * -1;table.repaint();}}        public void mouseReleased(MouseEvent e){         super.mouseReleased(e);         draggingRow = false;         table.repaint();        }    }    private Object[][] swapObjectList(  Object[][] origin,int fromRow,int toRow ){    Object [] mid = new Object [origin[0].length];    mid = origin[fromRow];    origin[fromRow] = origin[toRow];    origin[toRow] = mid ;return origin;    }}3.自定义的table：import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JTable;public class DragTable extends JTable  implements  ActionListener{/*** table*/private static final long serialVersionUID = 1L;public DragTable () {}@Overridepublic void actionPerformed(ActionEvent e) {// TODO Auto-generated method stub}}4.自定义的tablemodel：import javax.swing.table.AbstractTableModel;public class  DragTableModel extends AbstractTableModel{/*** table model*/private static final long serialVersionUID = 1L;private Object[][] data = null;public Object[][] getData() {return data;}public void setData(Object[][] data) {this.data = data;}private String [] header = null;public DragTableModel (Object[][] data ,String [] header){this.data = data;this.header = header;}public int getRowCount() {return data.length;}@Overridepublic int getColumnCount() {return header.length;}@Overridepublic String getColumnName(int column) {return header[column];}@Overridepublic Object getValueAt(int row, int column) {if(row >= 0){switch(column){  case 0:  return data[row][0];  case 1:  return data[row][1];case 2:  return data[row][2];  }}return null;}}