java - 单击按钮、ListSelectionListener 和 JTable

Question

它显示错误，但我不知道为什么。

单击搜索按钮更新 JTable 值。然后在选择一行后，它将所选行的最后一列的值打印到控制台。但是，如果我再次单击搜索按钮，则会出现错误。问题怎么解决？

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTable;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
import javax.swing.table.AbstractTableModel;



public class Test extends JFrame {
    Container c;
    public JButton search;
    public JTable table;

    public Test() {
        c= getContentPane();
        c.setLayout(new BorderLayout());

        table = new JTable(new MyTableModel());
        table.setPreferredScrollableViewportSize(new Dimension(500, 70));
        table.setFillsViewportHeight(true);
        table.setAutoCreateRowSorter(true);
        JScrollPane scrollPane = new JScrollPane(table, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
        table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF); 

        search = new JButton("Search");

        c.add(scrollPane, BorderLayout.WEST);
        c.add(search, BorderLayout.EAST);

        JSplitPane splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, scrollPane, search);
        splitPane.setOneTouchExpandable(true);
        splitPane.setResizeWeight(0.7);
        add(splitPane, BorderLayout.CENTER);

        ListenerSearch listenersearch = new ListenerSearch();
        search.addActionListener(listenersearch);
    }


    public class ListenerSearch implements ActionListener{
        public void actionPerformed(ActionEvent e){
            try{
                 String[] columnNames = {"A","B","C","D","E"};

                 Object[][] data = {
                            {"Kathy", "Smith",
                             "Snowboarding", new Integer(5), new Boolean(true)},
                            {"John", "Doe",
                             "Rowing", new Integer(3), new Boolean(true)},
                            {"Sue", "Black",
                             "Knitting", new Integer(2), new Boolean(false)},
                            {"Jane", "White",
                             "Speed reading", new Integer(20), new Boolean(true)},
                            {"Joe", "Brown",
                             "Pool", new Integer(10), new Boolean(false)}
                            };

                 MyTableModel changedtable = new MyTableModel();
                 changedtable.setString(columnNames);
                 changedtable.setObject(data);
                 table.setModel(changedtable);

                 table.getSelectionModel().addListSelectionListener(new ListSelectionListener(){
                        public void valueChanged(ListSelectionEvent event) {
                            System.out.println(table.getValueAt(table.getSelectedRow(), 4).toString());
                        }
                    }); 
            } catch(Exception ex) {
                ex.printStackTrace();
            }
        }
    }


    public static class MyTableModel extends AbstractTableModel { 
            public String[] columnNames = {"First Name",
                                            "Last Name",
                                            "Sport",
                                            "# of Years",
                                            "Vegetarian"};

            public void setString(String[] columnNameshelfer){
                columnNames=columnNameshelfer;
            }

            public Object[][] data = {
            {"Kathy", "Smith",
             "Snowboarding", new Integer(5), new Boolean(true)},
            {"John", "Doe",
             "Rowing", new Integer(3), new Boolean(true)},
            {"Sue", "Black",
             "Knitting", new Integer(2), new Boolean(false)},
            {"Jane", "White",
             "Speed reading", new Integer(20), new Boolean(true)},
            {"Joe", "Brown",
             "Pool", new Integer(10), new Boolean(false)},
            {"Kathy", "Smith",
             "Snowboarding", new Integer(5), new Boolean(true)},
            {"John", "Doe",
             "Rowing", new Integer(3), new Boolean(true)},
            {"Sue", "Black",
             "Knitting", new Integer(2), new Boolean(false)},
            {"Jane", "White",
             "Speed reading", new Integer(20), new Boolean(true)},
            {"Joe", "Brown",
             "Pool", new Integer(10), new Boolean(false)}
            };

            public void setObject(Object[][] datahelfer){
                data=datahelfer;
            }

            public int getColumnCount() {
                return columnNames.length;
            }

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

            public String getColumnName(int col) {
                return columnNames[col];
            }

            public Object getValueAt(int row, int col) {
                return data[row][col];
            }

            public Class getColumnClass(int c) {
                return getValueAt(0, c).getClass();
            }

            public boolean isCellEditable(int row, int col) {
                if (col < 1) {
                    return false;
                } else {
                    return true;
                }
            }

            public void setValueAt(Object value, int row, int col) {
                data[row][col] = value;
            }
    }



    public static void main(String[] args) throws Exception {
        Test window = new Test();
        window.setSize(800,400);
        window.setVisible(true);
        window.setTitle("Test");
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

错误信息:

java.lang.IndexOutOfBoundsException: Invalid index
at javax.swing.DefaultRowSorter.convertRowIndexToModel(DefaultRowSorter.java:514)
at javax.swing.JTable.convertRowIndexToModel(JTable.java:2641)
at javax.swing.JTable.getValueAt(JTable.java:2716)
at Test$ListenerSearch$1.valueChanged(Test.java:74)
at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:184)
at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:164)
at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:211)
at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:405)
at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:415)
at javax.swing.DefaultListSelectionModel.removeSelectionIntervalImpl(DefaultListSelectionModel.java:576)
at javax.swing.DefaultListSelectionModel.clearSelection(DefaultListSelectionModel.java:420)
at javax.swing.JTable.clearSelection(JTable.java:2116)
at javax.swing.JTable.clearSelectionAndLeadAnchor(JTable.java:2124)
at javax.swing.JTable.tableChanged(JTable.java:4369)
at javax.swing.JTable.setModel(JTable.java:3687)
at Test$ListenerSearch.actionPerformed(Test.java:70)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4687)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:735)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:694)
at java.awt.EventQueue$3.run(EventQueue.java:692)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:708)
at java.awt.EventQueue$4.run(EventQueue.java:706)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:705)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)

Answer 1

问题出在这行代码

 System.out.println(table.getValueAt(table.getSelectedRow(), 4).toString());

当一行未被选中时 table.getSelectedRow() 等于 -1 。所以当你调用

table.getValueAt(table.getSelectedRow(), 4).toString()

你得到错误是因为行 -1 和列 4 没有单元格

在像这样获取单元格值之前修复此检查 getSelectedRow() 值

if(table.getSelectedRow()>=0){ // check if a row is selected

       System.out.println(table.getValueAt(table.getSelectedRow(), 4).toString());

}

注意:这将修复您的错误。但我不知道您的程序的逻辑是什么。每次单击搜索按钮时您都会更改模型。这对我来说看起来很糟糕，但我不能肯定地说，直到我知道你的程序应该做什么。