Develop Reference

desktop.moveToTrash(srcFile); not for Java 8 [duplicate]

Java is the key here. I need to be able to delete files but users expect to be able to "undelete" from the recycle bin. As far as I can tell this isn't possible. Anyone know otherwise?

Ten years later, with Java 9, finally there is a builtin way to move files to the Trash Bin
java.awt.Desktop.moveToTrash(java.io.File):
public boolean moveToTrash​(File file)
Moves the specified file to the trash.
Parameters:
file - the file
Returns:
returns true if successfully moved the file to the trash.
The availability of this feature for the underlying platform can be tested with Desktop.isSupported​(Desktop.Action.MOVE_TO_TRASH).

For various reasons Windows has no concept of a folder that simply corresponds to the Recycle Bin.
The correct way is to use JNI to invoke the Windows SHFileOperation API, setting the FO_DELETE flag in the SHFILEOPSTRUCT structure.
SHFileOperation documention
Java example for copying a file using SHFileOperation (the Recycle Bin link in the same article doesn't work)

Java 9 has new method but in my case I am restricted to Java 8.
I found Java Native Access Platform that has hasTrash() and moveToTrash() method. I tested it on Win 10 and Mac OS (Worked) for me.
static boolean moveToTrash(String filePath) {
File file = new File(filePath);
FileUtils fileUtils = FileUtils.getInstance();
if (fileUtils.hasTrash()) {
try {
fileUtils.moveToTrash(new File[] { file });
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
} else {
System.out.println("No Trash");
return false;
}
}
Maven Repository
https://mvnrepository.com/artifact/net.java.dev.jna/jna-platform/5.1.0
Don't confuse It is Java Native Access Platform not Java Native Access

See the fileutil incubator project (part of the Java Desktop Integration Components project):
This incubator project is created to host those file utility functionalities, most of which are extensions to the java.io.File class in J2SE. There are frequent requests from Java developers for such features like: sending a file to trash bin, checking free disk space, accessing file attributes etc. This project addresses such frequently requested APIs.
Note, this should work not only on Windows, but on other platforms (Linux, Mac OS X) as well.

My 3 cents - use cmd util Recycle.exe with -f to force recycle (no prompt). Works perfectly.
public class Trash {
public void moveToTrash(File ... file) throws IOException {
moveToTrash(false, file);
}
public void promptMoveToTrash(File ... file) throws IOException {
moveToTrash(true, file);
}
private void moveToTrash(boolean withPrompt, File ... file) throws IOException {
String fileList = Stream.of(file).map(File::getAbsolutePath).reduce((f1, f2)->f1+" "+f2).orElse("");
Runtime.getRuntime().exec("Recycle.exe "+(withPrompt ? "" : "-f ")+fileList);
}
}

In JNA platform, the FileUtils doesn't use Win32 API. You should prefer W32FileUtils which supports Undo (restore the file from recycle bin).
Edit: as of the current version of JNA Platform (5.7.0), with FileUtils.getInstance(), this statement has become incorrect, and FileUtils will use the Win32 API.

How to have my java project to use some files without using their absolute path?

I have written a project where some images are used for the application's appearance and some text files will get created and deleted along the process. I only used the absolute path of all used files in order to see how the project would work, and now that it is finished I want to send it to someone else. so what I'm asking for is that how I can link those files to the project so that the other person doesn't have to set those absolute paths relative to their computer. something like, turning the final jar file with necessary files into a zip file and then that the person extracts the zip file and imports jar file, when runs it, the program work without any problems.
by the way, I add the images using ImageIcon class.
I'm using eclipse.

For files that you just want to read, such as images used in your app's icons:
Ship them the same way you ship your class files: In your jar or jmod file.
Use YourClassName.class.getResource or .getResourceAsStream to read these. They are not files, any APIs that need a File object can't work. Don't use those APIs (they are bad) - good APIs take a URI, URL, or InputStream, which works fine with this.
Example:
package com.foo;
public class MyMainApp {
public void example() {
Image image = new Image(MyMainApp.class.getResource("img/send.png");
}
public void example2() throws IOException {
try (var raw = MyMainApp.class.getResourceAsStream("/data/countries.txt")) {
BufferedReader in = new BufferedReader(
new InputStreamReader(raw, StandardCharsets.UTF_8));
for (String line = in.readLine(); line != null; line = in.readLine()) {
// do something with each country
}
}
}
}
This class file will end up in your jar as /com/foo/MyMainApp.class. That same jar file should also contain /com/foo/img/send.png and /data/countries.txt. (Note how starting the string argument you pass to getResource(AsStream) can start with a slash or not, which controls whether it's relative to the location of the class or to the root of the jar. Your choice as to what you find nicer).
For files that your app will create / update:
This shouldn't be anywhere near where your jar file is. That's late 80s/silly windows thinking. Applications are (or should be!) in places that you that that app cannot write to. In general the installation directory of an application is a read-only affair, and most certainly should not be containing a user's documents. These should be in the 'user home' or possibly in e.g. `My Documents'.
Example:
public void save() throws IOException {
Path p = Paths.get(System.getProperty("user.home"), "navids-app.save");
// save to that file.
}

File gets a full path of local source file as its name when uploaded using Java FTPClient

So i have a basic GUI application, where there is an option to upload image files to an ftp server. Everything works fine except one thing: the files are getting renamed during the upload. The new name of the file will be the full path of the directory, which contained the file.
So in my case, i have an image on the desktop: C:\Users\Bob\Desktop\image.png. When I select the file in the JfileChooser, the name is still just image.png. But when I click upload to FTP server, the file will be renamed to C:\Users\Bob\Desktop\image.png. So if I want to download that file, I have to use this path: /home/user/users/xy/images/C:\Users\Bob\Desktop\image.png in order to download it. Idk what causing this problem. I use FTPClient.putFileToPath(file,path) to upload the files, and it works fine, the files will be uploaded. I tried to copy a file from my machine to the ftp server with total commander, and this problem never occurred. I provided some code snippet, which does the uploading job.
uploadmenu.getUploadBtn().addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if(!uploadMenuValidate()){
for(File f : img_container){
try {
//This still gives me the normal file name
System.out.println(f.getName());
ftp.putFileToPath(f, FtpClient.DEST_DIR+SQLData.APP_USERNAME+"/"+f);
} catch (IOException ex) {
ex.printStackTrace();
}
}
popup.setVisible(false);
}
}
});
I have all the files in the img_container array that I selected in the JFileChooser.

The File.toString() returns:
Returns the pathname string of this abstract pathname
You want to use File.getName():
ftp.putFileToPath(f, FtpClient.DEST_DIR+SQLData.APP_USERNAME+"/"+f.getName());

Proper packaging of runnable Jar project in netbeans

So my task is to create a small program that displays a list of media files and run these media files with default OS media player separately.
My current solution was to create a package that holds all media files, something like:
-com.media
|_a.mp4
|_b.mp4
The following code copies to a temp dir the selected mp4, then runs the default os media player:
public File copyTempMedia(File tempAppFolder, String videoName) {
URL f = getClass().getResource(String.format("%s/%s", Constants.MEDIA_LOCATION, videoName));
File from = new File(f.getPath());
File to = new File(tempAppFolder.getAbsolutePath());
try {
FileUtils.copyFileToDirectory(from, to);
} catch (IOException ex) {
Logger.getLogger(MediGUIModel.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println("Temp video copied: " + to.getAbsolutePath() + "/" + to.getName());
return to;
}
public void triggerMediaPlayer(String fileLocation) {
System.out.println("Triggering media player: " + fileLocation);
try {
if (OPERATIN_SYSTEM.contains("Linux")) {
Runtime.getRuntime().exec("sh -c " + fileLocation);
} else if (OPERATIN_SYSTEM.contains("Windows")) {
Runtime.getRuntime().exec("cmd /c " + fileLocation);
}
} catch (IOException ex) {
Logger.getLogger(MediGUIModel.class.getName()).log(Level.SEVERE, null, ex);
ex.printStackTrace();
}
}
When I run the program through Netbeans it works as espected, but when I do a clean/build the run the .jar created from the build, the media file doesn't seem to be read, so my questions are:
Why does it work through Netbeans and not through build .jar ?
Is this the best solution to this problem ?
Should I package the media differently ?
Thanks in advance.
Edit
So after running through console instead of double clicking jar, is get a null pointer exception in the line where I read the file:
URL f = getClass().getResource(String.format("%s/%s", Constants.MEDIA_LOCATION, videoName));
Why does it work in Netebeans but not on build/jar ?
Is there another place in the jar I could place the media files, so that they are read with no problem through getResource or getResourceAsStream ?

When you run the project in NetBeans, it isn't running the executable jar like java -jar yourproject.jar. Instead it sets the classpath to build/classes sort of like java -cp build/classes com.media.YourMainClass. This means your video files are actual files located in yourproject/build/classes/com/media, and they can be accessed as normal files in the filesystem and copied like a normal file. When you run from the jar, the files are packed in the jar file and can't be copied using simple file copy commands.
Instead of getting the URL by calling getClass().getResource(), try getting an InputStream by calling getClass().getResourceAsStream(). You can then write a simple loop to copy the bytes from the input stream to your temporary file.

This snippet may be helpful:
BufferedInputStream result = (BufferedInputStream) getClass().getResourceAsStream("/com/media/a.mp4");
byte[] bytes = new byte[4098];
try {
result.read(bytes);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(new String(bytes));
You'll need to read the bytes in a loop or something but that should work without needing a separate jar.

I think it's not a good idea to put your media files in the jar because you need to rebuild the project if you want to change one and the jar size will grow.
Use:
File from = new File(String.format("%s/%s", Constants.MEDIA_LOCATION,videoName));
To load your files from the same folder as the jar.
If you want to keep the medias in the jar, create a Maven project and put the mp4 in src/main/resources.
Use maven to create a fat jar and the src/main/resources will be included in the jar.
See 'maven-shade-plugin' to configure the pom.xml and https://www.mkyong.com/maven/create-a-fat-jar-file-maven-shade-plugin/
Then you can use the others maven's great properties!
See Reading a resource file from within jar
Edit
After some tries, i can't get it right with 'getResource' from the jar.
The path you get from within the jar is like:file:/C:/.../JavaApplication4/dist/JavaApplication4.jar!/test.txt
and not recognized as a valid filesystem path.
You can use 'getResourceAsStream' and copy the file from the jar to the local folder.
InputStream in;
OutputStream out;
IOUtils.copy(in,out);
in.close();
out.close();

Ok so I found a solution:
Create a separate project with media.*.mp4.
Export as Jar library.
Import library to desktop app.
Make sure library is in classpath.
This solution works for me...
If anyone has a better solution, happy to hear, hopefully before bounty is up :)

HTML file not opening in executable jar

I have a program I have written in Eclipse and it runs fine -- the HTML file opens when I run the program through Eclipse. But when I create a jar file of the program, everything else runs fine except this HTML file won't open in the browser (or anywhere):
operation.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
try {
File htmlFile = new File("help/operation.html");
Desktop.getDesktop().browse(htmlFile.toURI());
} catch (MalformedURLException MURLe) {
MURLe.printStackTrace();
} catch (IOException ioE) {
ioE.printStackTrace();
}
}
});
The rest of the program runs fine, and my images and sounds work fine and are opened, but this HTML file will not open in the menu or with the Ctrl+key shortcut. Your help is appreciated. Thanks.

When you have a file inside your jar, you cannot access it like you are doing now.
You need to read it as a stream, that's the only way.

Suppose your project is foo. Then help/operation.html will refer to
..\abc\help\operation.html
But the deployed jar file will not contain it.
You have include this operation.html file in your source code (where you write code).
Then eclipse (or any IDE) will add it into your jar file when you deploy it.
And now you can use your file as follows.
Suppose your file is present in as shown in figure.
Now you can refer your html file from any class. In this example referring it from
Accesser class.
File resFile = new File(Accesser.class.getResource("operation.html").toURI());
If you want to open your file in browser you will have to copy this file into the
user's System.
File htmlFile = new File("operation.html");
if(!htmlFile.exists) {
Files.copy(resFile.toPath(), htmlFile.toPath());
}
Desktop.getDesktop().browse(htmlFile.toURI());
Files is present in java.nio.file package