java - 将 ListModels 设置为 JList

Question

我有一段代码，它根据文件的内容设置 ListModel 并将其添加到 jList 中。当我第一次选择文件时，代码运行正确。当我选择第二个文件时，它给出数组越界异常。 runList.setModel(model) 发生错误；

这是代码

        protected class OpenFileListener implements ActionListener
 {

    @Override
    public void actionPerformed(ActionEvent ae) {
        try
        {
        JFileChooser fileChooser = new JFileChooser(); 
        fileChooser.setFileFilter(new FileNameExtensionFilter("*.txt", "txt"));
        fileChooser.setCurrentDirectory(new File("."));
        int result = fileChooser.showOpenDialog(null);
        fileName = fileChooser.getSelectedFile().getPath();
        molfindOutText.setText(getFileName());
        DefaultListModel model = new DefaultListModel();
        runList.setModel(model);
        File f = new File(getFileName());
        Scanner scanner = new Scanner(f);
        lineNo = 0 ;
        int i = 0;
        idLines = new ArrayList();
        while (scanner.hasNextLine())
        {
            String line = scanner.nextLine();
            lineNo = lineNo+1;
            if (line.matches(".*COMPOUND_IDENTIFICATION_RUN.*"))
            {
            model.add(i, line);
            runList.setSelectedIndex(0);
            idLines.add(lineNo);
            i++;
            }
        }
        currentRun = 1;
        if (idLines.size()>1)
        {
        extractRunInfo(idLines.get(0),idLines.get(1)-2);
        }
        else
        {
        extractRunInfo(idLines.get(0),lineNo); 
        }
        scanner.close();
        runList.addListSelectionListener(lsl);
        }
        catch(Exception e) 
        {
    System.out.println(e.toString());
    }

    }

打印堆栈跟踪

java.lang.ArrayIndexOutOfBoundsException: -1
    at java.util.ArrayList.get(ArrayList.java:324)
    at edu.uconn.pharmacy.molfind.AnalysisPanel$1.valueChanged(AnalysisPanel.java:99)
    at javax.swing.JList.fireSelectionValueChanged(JList.java:1795)
    at javax.swing.JList$ListSelectionHandler.valueChanged(JList.java:1809)
    at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:167)
    at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:147)
    at javax.swing.DefaultListSelectionModel.fireValueChanged(DefaultListSelectionModel.java:194)
    at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:388)
    at javax.swing.DefaultListSelectionModel.changeSelection(DefaultListSelectionModel.java:398)
    at javax.swing.DefaultListSelectionModel.removeSelectionIntervalImpl(DefaultListSelectionModel.java:559)
    at javax.swing.DefaultListSelectionModel.clearSelection(DefaultListSelectionModel.java:403)
    at javax.swing.JList.clearSelection(JList.java:2043)
    at javax.swing.JList.setModel(JList.java:1676)
    at edu.uconn.pharmacy.molfind.AnalysisPanel$OpenFileListener.actionPerformed(AnalysisPanel.java:131)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
    at java.awt.Component.processMouseEvent(Component.java:6373)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
    at java.awt.Component.processEvent(Component.java:6138)
    at java.awt.Container.processEvent(Container.java:2085)
    at java.awt.Component.dispatchEventImpl(Component.java:4735)
    at java.awt.Container.dispatchEventImpl(Container.java:2143)
    at java.awt.Component.dispatchEvent(Component.java:4565)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4621)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4282)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4212)
    at java.awt.Container.dispatchEventImpl(Container.java:2129)
    at java.awt.Window.dispatchEventImpl(Window.java:2478)
    at java.awt.Component.dispatchEvent(Component.java:4565)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:679)
    at java.awt.EventQueue.access$000(EventQueue.java:85)
    at java.awt.EventQueue$1.run(EventQueue.java:638)
    at java.awt.EventQueue$1.run(EventQueue.java:636)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
    at java.awt.EventQueue$2.run(EventQueue.java:652)
    at java.awt.EventQueue$2.run(EventQueue.java:650)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:649)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

Answer 1

错误似乎出在您在列表上注册的选择监听器中，该监听器正在尝试访问(现在为空)列表的元素。堆栈跟踪中的第二个条目告诉您在哪里查找:

at edu.uconn.pharmacy.molfind.AnalysisPanel$1.valueChanged(AnalysisPanel.java:99)

可能您只需要 valueChanged() 来检查列表是否为空，并且在这种情况下不执行任何操作。