Why does JfileChooser.showOpenDialog hang on Mac O

问题:

I am using Eclipse to develop an SWT application. The following code works on Windows but not on Macintosh:

import javax.swing.JFileChooser;

public class Test {
    public static void main(String[] args) {
        final JFileChooser fc = new JFileChooser();
        int ret = fc.showOpenDialog(null);
        System.out.println("ret  = " + ret);
    }
}

Upon entering showOpenDialog, the Mac cursor spins forever, and I get the following in the Java console:

2013-09-05 08:20:40.568 java[1271:707] [Java CocoaComponent compatibility mode]: Enabled
2013-09-05 08:20:40.569 java[1271:707] [Java CocoaComponent compatibility mode]: Setting timeout for SWT to 0.100000
2013-09-05 08:20:41.227 java[1271:dd03] *** -[NSConditionLock unlock]: lock (<NSConditionLock: 0x7fa211e82600> '(null)') unlocked when not locked
2013-09-05 08:20:41.227 java[1271:dd03] *** Break on _NSLockError() to debug.

I've tried Java 1.6, Java 1.7. I've tried setting -Dcom.apple.awt.CocoaComponent.CompatibilityMode=false -XstartOnFirstThread but that has no effect.

This must be something really basic. What am I missing?

回答1:

Good day to everybody having same problem!

Maybe i am too late to answer this but it might help someone having this issue.

After some research i have tries to play around with LookAndFeel. Then i tried changing look and feel upon opening "showSaveDialog()" and it seems to work. I cannot guarantee that it works 100% of the time, but till now it has worked to me just fine("did not succeed to hang :)"). Ill report again if it fails :) Here is my code:

//Update: It it better to user FileDialogg for mac os x

private File saveFile() {
    String osName = System.getProperty("os.name");
    String homeDir = System.getProperty("user.home");
    File selectedPath = null;
    if (osName.equals("Mac OS X")) {
        System.setProperty("apple.awt.fileDialogForDirectories", "true");
        FileDialog fd = new FileDialog(f, "Choose a file", FileDialog.LOAD);
        fd.setDirectory(homeDir);
        fd.setVisible(true);
        String filename = fd.getDirectory();
        selectedPath = new File(filename);
        if (filename == null) {
            System.out.println("You cancelled the choice");
        } else {
            System.out.println("You chose " + filename);
        }
        System.setProperty("apple.awt.fileDialogForDirectories", "true");
    } else {
        fc.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        fc.setCurrentDirectory(new File(homeDir));
        fc.setAcceptAllFileFilterUsed(false);
        fc.showOpenDialog(null);
        selectedPath = fc.getSelectedFile();
    }
    return selectedPath;
}

Code is not perfect but u get the point :)

回答2:

This program runs fine on my Mac and returns in less than a second:

import java.io.*;
import javax.swing.*;
import javax.swing.filechooser.*;

/** to isolate and understand why JFileChooser is blocking. */
public class DebugJFC {

    public static void main(String[] args) {
        System.err.println("JFileChooser ");
        JFileChooser listFC= new JFileChooser(".");
        System.err.println("done");
        }

    }

When I run it on Linux, it hangs after printing "JFileChooser " and before printing "done". Worse yet, the "new JFileChooser" statement has worked for years on Linux, and only started failing today. What's up with that!??

Linux: > java -version java version "1.7.0_45" Java(TM) SE Runtime Environment (build 1.7.0_45-b18) Java HotSpot(TM) 64-Bit Server VM (build 24.45-b08, mixed mode)

Mac: > java -version java version "1.6.0_65" Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609) Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)