Tough question here. How do you open a file in java, in the way that when you double click on the file it automatically opens in a java application.
I'm making a musicplayer (first real big Java project for me) and I have no clue how to acheive this. When you open, lets say, a .mp3 file it will open in whatever default program you have selected for it (such as VLC mediaplayer or Windows Media Player). What I want is to be able to set the .jar file of my application as the default program for .mp3 files, and then to be able to actually launch the files in the application.
When I currently try to open a file with the application I get a windows error saying "This app cannot be executed on your pc". But when I launch the .jar itself without doing it by trying to open a .mp3 file it runs just fine.
Does anyone know how to acheive what I want? Many thanks in advance!
---edit---
I do not mean that you can select a default program for the mp3 file. The problem is that windows throws the error shown above, and that I dont know how to handle the application being launched by opening a file (which does not ope due to the error).
I think the problem is that you have to open a file with a .exe , so you sshould use an exe wrapper (I use jsmooth: download here)
BUT, before you do that, you need to accept that info. So in the main class, the "args" is a list of info about how it's being launched. If you are opening a file, the array's first argument will be the opened file's destination. SO I would accept it like this:
if (args.length > 0) {
File f = new File(args[0]);
start_the_application_with_a_file(f);
} else {
start_the_application_without_a_file();
}
C:\ProgramData\Oracle\Java\javapath\java.exe -jar "C:\Program Files\YourApp.jar" %* within a batch-file (.cmd) might do it.
Related
For some unusual reason, when I am using FileWriter for Java Netbean, the file gets written into this directory:
C:\Users\myname\AppData\Roaming\NetBeans\7.2\config\GF3\domain1
rather than to my working directory, which is at the desktop.
I used this code to check my User Directory, and it returns this:
System.out.println(System.getProperty("user.dir"));
INFO: C:\Users\myname\AppData\Roaming\NetBeans\7.2\config\GF3\domain1
which is obviously NOT my working directory where my source code is. I thought I could have accidentally configured Netbeans to change the directory, but I checked through NetBeans menu and can't figure out how to undo this.
I have never had this problem before in my previous projects. As simple as the following code, the file should appear in my working directory.
File file = new File("myFile.xml");
Instead now I'm being forced to enter the path name to make the file save into my working directory, which is not going to be dynamic if I change computer.
String dir = "C:\\Users\\myname\\Desktop\\Assignment\\IRAssignmentJ\\";
File file = new File(dir + "myFile.xml");
Please enlighten me how do I solve this.
rather than to my working directory, which is at the desktop
No it isn't. The current working directory is whereever the file got saved, by definition. If Netbeans chooses to change directory to where it was saved, there's nothing you can do about it. If you want it in your home directory, there is a system property for that. If you want it saved somewhere else, use a full pathname.
But the behaviour of the application under Netbeans is of little interest. What matters is when you run it as though standalone, like a customer would.
I am trying to edit the java.security file in windows. When I add an entry to it and try to save, it says 'Access Denied'. How do I change the permissions to this file.
I have also tried by making notepad to Run as administrator but it didn't work.
Please help.
Try this and say if it works. It worked for me while opening hosts file.
http://www.labnol.org/software/edit-hosts-files-as-administrator/13673/
edit:
The relevant information from the linked page:
Step 1. Open your Windows start menu, search for the notepad application and then right click the notepad icon.
Step 2. Choose “Run as administrator” and then, while inside notepad, browse to folder (java.home\lib\security\java.security).
You can now edit and save that file in the same folder without any issues. To recap, the trick is that instead of directly opening a protected file in the associated application, you run the application first as an administrator and then open the file inside it.
1) Copy original java.security file to desktop.
2) Edit the file there and save it.
3) Copy the file to %JAVA_HOME%/\jre\lib\security
4) Replace the original file with modified one.
I have a file on linux ubuntu server hosted with path name /home/kishor/project/detail/.
When I made a web app in window to upload and download file from specified location i used path "c:\kishor\projects\detail\" for saving in window.
For my surprise when i used window file path name in my server i am still able to get files and upload them, i.e, "c:\kishor\projects\detail\".
Can anyone explain why it is working (as window and linux both use different file path pattern).
I've seen this work too. What linux does is create a file whose name is literally c:\kishor\projects\detail\
If you say, you can "upload" files... perhaps there is now a new folder structure.
Some months ago i saw a similar thing: Under /home/webadmin was an new structure "/c:/Users/...."
I need to write a java program to open a specific file extension (This is to open a .pef file). This java program is being written to open this .pef file and print it. But I don't know how to write a program that can open the .pef file extension by default.
See:
Desktop.open(File) Launches the associated application to open the file.
Desktop.edit(File) Launches the associated editor application and opens a file for editing.
Desktop.print(File) Prints a file with the native desktop printing facility, using the associated application's print command.
This presumes the application has already been associated with the file-type. To create the file association, launch your app. using Java Web Start & declare the file type in the launch file.
This solution is Windows specific
In this post I am assuming that your program is already capable of reading files of type .pef and printing them. If not then please refer to Treebranch's and Himanshu's posts here to figure out how to do so. Next I will assume that your program is to be invoked on the Windows command line as:
program.exe <filename.pef>
To programatically change the association, follow these steps:
Define a file type
ftype peffile="program.exe" "%1"
Remember to use the absolute path of program.exe here.
Associate this file type with .pef
assoc .pef=peffile
I am not familiar with this file type, but I am guessing you are going to have to read the bytes of the file and then go from there. You should be able to use a FileInputStream. Try looking at this tutorial.
You can use FileInputStream to read a file.
FileInputStream fr=new FileInputStream("xyz.pef");
int i=0;
while((i=fr.read())!=-1)
System.out.print((char)i);
fr.close();
I am trying to write a log file from an applet.
When running as a Java application, I am able to write to the files,
but when running as an applet, I get .\logs\test.log (The system cannot find the path specified).
How do I permit it to write to disk, while debugging using eclipse?
EDIT: is it because of the backslashes?
You should write whatever you want from applet in temp file, to create temp file Try this
. Also you get system temp folder in java and create your file there, Read this. #Yoni is right you have limited permissions when you are in applet.