java - Java Swing 中的 IllegalComponentStateException

Question

在做一个基础 java swing 程序时，我有一个奇怪的错误，我只在我的电脑上出现过(我在另外 2 台电脑上试过，一切正常)。

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

public class ModalDialogsTest extends JFrame implements ActionListener{

        private JButton choice;

        ModalDialogsTest(){
                setSize(400,300);
                JPanel panel = new JPanel();
                getContentPane().add(panel);
                panel.setLayout(new BoxLayout(panel,BoxLayout.Y_AXIS));
            choice = new JButton("My button");
            panel.add(choice);
            choice.addActionListener(this);
        }

        public void actionPerformed(ActionEvent event){
                        simpleStringChoiceDialog();
        }

        private void simpleStringChoiceDialog(){
                Object[] possibilities = {"choice 1", "choice 2", "choice 3"};
                String s = (String)JOptionPane.showInputDialog(
                                    this, null, null,
                                    JOptionPane.PLAIN_MESSAGE, null,
                                    possibilities, possibilities[0]);
                System.out.println(s);
        }

        public static void main(String[] args) {
                ModalDialogsTest newWindow = new ModalDialogsTest();
                newWindow.setVisible(true);
        }
}

问题是当我点击下拉菜单进行选择时出现错误。错误是:

    java.awt.IllegalComponentStateException: component must be showing on the screen to determine its location
    at java.awt.Component.getLocationOnScreen_NoTreeLock(Component.java:2044)
    at java.awt.Component.getLocationOnScreen(Component.java:2018)
    at sun.lwawt.macosx.CAccessibility$22.call(CAccessibility.java:390)
    at sun.lwawt.macosx.CAccessibility$22.call(CAccessibility.java:388)
    at sun.lwawt.macosx.LWCToolkit$CallableWrapper.run(LWCToolkit.java:527)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:241)
    at sun.lwawt.macosx.LWCToolkit$CPeerEvent.dispatch(LWCToolkit.java:684)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:721)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:691)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:155)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:182)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:221)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:219)
    at java.awt.Dialog.show(Dialog.java:1077)
    at javax.swing.JOptionPane.showInputDialog(JOptionPane.java:583)
    at ModalDialogsTest.simpleStringChoiceDialog(ModalDialogsTest.java:109)
    at ModalDialogsTest.actionPerformed(ModalDialogsTest.java:70)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$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:723)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:682)
    at java.awt.EventQueue$3.run(EventQueue.java:680)
    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:696)
    at java.awt.EventQueue$4.run(EventQueue.java:694)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
    choice 2

如您所见，发生了一个错误，但我仍然可以得到该函数的结果，所以我不知道出了什么问题……有什么线索吗？我在 MacOS X Mountain Lion 上使用 Java 7。

好的，这是你问我的结果:
System.out.println(System.getProperty("java.vm.name"));给了我:

Java HotSpot(TM) 64-Bit Server VM.

System.getProperties().list(System.out);给了我:

-- listing properties --
java.runtime.name=Java(TM) SE Runtime Environment
sun.boot.library.path=/Library/Java/JavaVirtualMachines/jdk...
java.vm.version=23.3-b01
user.country.format=IE
gopherProxySet=false
java.vm.vendor=Oracle Corporation
java.vendor.url=http://java.oracle.com/
path.separator=:
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
file.encoding.pkg=sun.io
user.country=FR
sun.java.launcher=SUN_STANDARD
sun.os.patch.level=unknown
java.vm.specification.name=Java Virtual Machine Specification
user.dir=/Users/hugo/Documents/workspace/dialogs
java.runtime.version=1.7.0_07-b10
java.awt.graphicsenv=sun.awt.CGraphicsEnvironment
java.endorsed.dirs=/Library/Java/JavaVirtualMachines/jdk...
os.arch=x86_64
java.io.tmpdir=/var/folders/2n/q2bb2df90qqb_x38djlwx...
line.separator=

java.vm.specification.vendor=Oracle Corporation
os.name=Mac OS X
sun.jnu.encoding=US-ASCII
java.library.path=/Users/hugo/Library/Java/Extensions:/...
java.specification.name=Java Platform API Specification
java.class.version=51.0
sun.management.compiler=HotSpot 64-Bit Tiered Compilers
os.version=10.8
http.nonProxyHosts=local|*.local|169.254/16|*.169.254/16
user.home=/Users/hugo
user.timezone=
java.awt.printerjob=sun.lwawt.macosx.CPrinterJob
file.encoding=US-ASCII
java.specification.version=1.7
user.name=hugo
java.class.path=/Users/hugo/Documents/workspace/dialo...
java.vm.specification.version=1.7
sun.arch.data.model=64
java.home=/Library/Java/JavaVirtualMachines/jdk...
sun.java.command=ModalDialogsTest
java.specification.vendor=Oracle Corporation
user.language=fr
user.language.format=en
awt.toolkit=sun.lwawt.macosx.LWCToolkit
java.vm.info=mixed mode
java.version=1.7.0_07
java.ext.dirs=/Users/hugo/Library/Java/Extensions:/...
sun.boot.class.path=/Library/Java/JavaVirtualMachines/jdk...
java.vendor=Oracle Corporation
file.separator=/
java.vendor.url.bug=http://bugreport.sun.com/bugreport/
sun.cpu.endian=little
sun.io.unicode.encoding=UnicodeBig
sun.font.fontmanager=sun.font.CFontManager
socksNonProxyHosts=local|*.local|169.254/16|*.169.254/16
ftp.nonProxyHosts=local|*.local|169.254/16|*.169.254/16
sun.cpu.isalist=

编辑:我忘了说我在另一台与我的完全一样的 Mac 上试过(除了我的有更多内存但没关系)和一台 Windows 7 电脑。

Answer 1

我在 Mac Yosemite 上使用 Java 7 时遇到了同样的问题。在我的例子中，它是由一个名为“Cinch”的第三方工具引起的，我用它来在桌面上排列我的窗口。停用该工具让异常消失。