Question

我这里有一个java swing程序，可以作为一个简单的电话簿。我使用单维数组来保存输入的值。但当我选择删除删除记录时，它会给我和错误。我真的不知道。

这是用于删除记录的函数

    public void delete()
        {
    delname = (String) JOptionPane.showInputDialog(null, "Enter name to                 delete", "Delete", JOptionPane.QUESTION_MESSAGE);

    for(int ctr=0; ctr<index; ctr++)
    {
        if(name[ctr].equals(delname))
        {
            name[ctr]= "";
            name=rem(delname,name);
            lisroutnum.remove(ctr);
            JOptionPane.showMessageDialog(null, "Contact Deleted!", "Succesful", JOptionPane.INFORMATION_MESSAGE);
            setVisible(true);
        }
        else
        {
            JOptionPane.showMessageDialog(null, "Name doesn't Exist!", "Error", JOptionPane.ERROR_MESSAGE);
            setVisible(true);
        }
    }
}`

这是rem函数

    public String[] rem(String delname, String[] name)
{
    int x= name.length-1, i=0;
    String[] newname = new String[x];

    for(int c=0; c< x; c++)
    {
        if(!name[c].equals(delname))
        {
            newname[c]= name[c];
        }
    }
    return newname;
}

这是错误

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Project.Project.rem(Project.java:263)
at Project.Project.delete(Project.java:243)
at Project.Project.actionPerformed(Project.java:375)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2346)
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:6527)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6292)
at java.awt.Container.processEvent(Container.java:2234)
at java.awt.Component.dispatchEventImpl(Component.java:4883)
at java.awt.Container.dispatchEventImpl(Container.java:2292)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4898)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4533)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4462)
at java.awt.Container.dispatchEventImpl(Container.java:2278)
at java.awt.Window.dispatchEventImpl(Window.java:2739)
at java.awt.Component.dispatchEvent(Component.java:4705)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:746)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:86)
at java.awt.EventQueue$4.run(EventQueue.java:719)
at java.awt.EventQueue$4.run(EventQueue.java:717)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:716)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

请帮帮我！

从数组错误中删除元素

0 个答案: