I'm attempting to use eXist-db in embedded mode in a Java program to produce an interactive fiction game.
Is there any information on invoking backups and restores from within my own java application, so as to initially load the story and all files, and then to perform a save/restore function?
Also, any suggestions on how to format my xml for such use would be appreciated.
You can invoke the backup directly by passing in the URI of your embedded eXist instance. For example:
import org.exist.backup.Backup;
//omitted for brevity
final Backup backup = new Backup("admin, "adminPass", "xmldb:exist:///db")
backup.backup(false, null);
You can use any collection path instead of just /db. Also if you are running this from within a Swing application you can use:
backup.backup(true, frame);
To have a backup dialog appear.
Hope that helps.
Related
I am working on a GUI application that uses JavaFX(not fxml) and exported as a JAR. For slow machine, impatient user click more than once on JAR, and multiple instances of application started.
I'm looking for a solution to let only one instance can be run at a time on a system and if the user clicks again while the application is running nothing happens. I think it's called singleton but don't know how to implement it.
You could try JUnique. It's an open source library doing exactly what you ask for. Import junique-1.0.4.jar to your project as a library. It's just 10kb file.
It's manual neatly describes how to implement it on a project. For a JavaFX application, implementation would look something like this:
Make sure to import these classes to your main
import it.sauronsoftware.junique.AlreadyLockedException;
import it.sauronsoftware.junique.JUnique;
public static void main(String[] args) {
String appId = "myapplicationid";
boolean alreadyRunning;
try {
JUnique.acquireLock(appId);
alreadyRunning = false;
} catch (AlreadyLockedException e) {
alreadyRunning = true;
}
if (!alreadyRunning) {
launch(args); // <-- This the your default JavaFX start sequence
}else{ //This else is optional. Just to free up memory if you're calling the program from a terminal.
System.exit(1);
}
}
One easy solution that I've used is, when you start the application, it creates a file (I named it .lock but you can call it whatever you want), unless the file already exists, in which case the application terminates its execution instead of creating the file.
You will need to bind your application with a resource. It can be a file, port etc.
You can change the code on startup to check if the file is locked. The below code will give you some idea
FileOutputStream foStream = new FileOutputStream("/tmp/testfile.txt");
FileChannel channel = fileOutputStream.getChannel();
FileLock lock = channel.lock();
If you'd properly package your JavaFX code as a real application instead of just throwing it into a jar, you might get that functionality for free and without all these hacks. If I package my JavaFX code on my Mac with the jpackage tool, the result will be a full featured macOS application. That means that when I double-click its icon somewhere several times, only one instance of the application will be started. This is the default behaviour on Macs and properly packaged JavaFX applications just stick to that rule too. I can't say however what the behaviour on Windows or Linux is because I currently don't have such a box running. Maybe someone who knows can add this as a comment.
I am new to JavaFX so here is a scenario:
I have running Mongo as Windows service
I have buttons in JavaFX stage for backup and restore databases in Mongo
It is possible to backup or restore database by putting code in onClick method of buttons? Can someone tell me how to do this or provide code for this?
Path: "Path to Store Database Backup in My Computer"
Method for backup: public void bBackup() { /* Code for backup data */ }
Method for restore: public void bRestore() { /* Code for restore data */ }
recently I've started a project called mongodbdump-java-wrapper to wrap mongodump.exe and mongorestore.exe mongodb executable from java.
You could clone it from : github project. This project includes integration tests (a way to know how implement backup/restore).
We are using NetBeans Platform 7.0.1, and have implemented support for a new language using this (now “obsolete”) tutorial.
Since all our contents are stored in a database, and not on files, we open them like this:
FileSystem fs = FileUtil.createMemoryFileSystem();
FileObject fo = fs.getRoot().createData(fileName, fileExtension);
… write contents from database to `fo` ….
DataObject data = MyMultiDataObject.find(fo);
EditorCookie.Observable cookie = data.getCookie(EditorCookie.Observable.class);
cookie.open();
… forces undock of editor window …
And, in our layer.xml, have added a custom button to Save that sends the content back to the database.
However, when the user closes the file (by either closing the tab or the window), we haven’t figured a way of saving it.
Adding a PropertyChangeListener to the Cookie and watching for PROP_DOCUMENT (and newValue() == null) seems to do the trick for when the window is closed. But how does one get the return value from the confirmation window (I’m referring to when the file is closed after changes, the message File xxx.xxx is modified. Save it?)?
Well, it seems we've been approaching the problem in the wrong way.
Since we are opening the file in-memory, it was suggested in the netbeans-dev list that we should listen for changes in the file itself, by using
fo.addFileChangeListener(new CustomFileChangeListener());
public class CustomFileChangeListener implements FileChangeListener {
#Override
public void fileChanged(FileEvent fe) {
... file has been saved in the editor, sync with database ...
}
}
And keep it synchronized that way, taking advantage of the built-in NetBeans Platform "save" functionality.
I have a CompareEditorInput shown in CompareEditor, it compares textual data. I need to reload CompareEditorInput when it is changed outside of CompareEditor.
Open compare editor (CompareUI.openCompareEditor(input))
Compare input is changed (ISteramContentAccessor.getContents() returns changed content)
Tell opened compare editor to reload CompareEditorInput <- needs to be implemented.
You could call setInput(sameInput) on CompareEditor, but since CompareEditor is internal and setInput() is not public in EditorPart then a workaround is to call IEditorPart.init(IEditorSite site, IEditorInput input).
IWorkbenchWindow wnd = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
IEditorPart editor = wnd.getActivePage().findEditor(input);
editor.init((IEditorSite) editor.getSite(), input);
The new java io package java.nio.file package provides a file change notification API, called the Watch Service API. using this you can monitor the file on the disk and track for any changes. Check this for further reference
Create a separate thread which uses the WatchService API and monitors the file in the background and if finds any changes on disk, notify the user.
From within Java, I am opening an Excel file with the default file handler (MS Excel, in this case :-) ) using the method described in this stackoverflow question:
Desktop dt = Desktop.getDesktop();
dt.open(new File(filename));
However, the Excel program doesn't get the focus. Is there any easy way to do so?
Edit: There is a related stackoverflow question for C#, but I didn't find any similar Java method.
Edit 2: I've did some simple tests, and discovered that Excel starts and gets the focus whenever no instance of Excel is running. When Excel is already open en NOT minimized, the application doesn't get the focus. If instead the Excel Windows was minimized, the above code will trigger a maximization of the window and Excel getting the focus (or vice versa :-) ).
If you only care about Windows (implied in the question), you can change the way you invoke Excel: use "cmd start...".
I have been using this piece of code to launch Windows applications for some time now. Works every time. It relies on the file association in Windows to find the application. The launched application becomes the focused window on the desktop.
In your case, Excel should be associated with .xls, .csv and other typical extensions. If it is, Windows will launch Excel, passing your file to it.
Usage:
MyUtilClass.startApplication( "c:\\mydir\\myfile.csv", "my window title" );
file is the full path to the input file for Excel and title is the window title (the application may or may not take it - Excel changes the window title).
public static void startApplication( String file, String title )
{
try
{
Runtime.getRuntime().exec( new String[] { "cmd", "/c", "start", title, file } );
}
catch( Exception e )
{
System.out.println( e.getMessage() );
}
}
From a scala-program, which runs in the JVM too, I can open an application, and that get's the focus by default. (Tested with xUbuntu, which is a kind of Linux).
import java.awt.Desktop
val dt = Desktop.getDesktop ();
dt.open (new java.io.File ("euler166.svg"));
I can't say, whether this is specific for Linux, or maybe something else - however starting Inkscape in my example, excel in yours, may take a few seconds, while the user impatiently clicks in the javaprogram again, thereby claiming the cursor back. Did you check for that?
You could then change to the last application, at least on Linux and Windows with ALT-Tab aka Meta-Tab (again shown in scala code, which you can easily transform to javacode, I'm sure):
import java.awt.Robot
import java.awt.event._
val rob = new Robot ()
rob.keyPress (KeyEvent.VK_META)
rob.keyPress (KeyEvent.VK_TAB)
rob.keyRelease (KeyEvent.VK_TAB)
rob.keyRelease (KeyEvent.VK_META)
but unfortunately the unknown source off more trouble, also known as user, might do nothing, so switching would be the false thing to do. Maybe with a thread, which checks for a certain amount of time, whether the java-program has the focus, but it keeps a form of roulette, in an interactional environment, because the user may have a fast or slow machine, or change to a third application meanwhile, and so on. Maybe a hint before triggering the new app is the best you can do?