So I make a couple of images for my eclipse view plugin. Works perfectly. I wake up the next day and the program now tells me that it can no longer find those files. The files are definitely still in the same place I left them, and I haven't touched the code in 24 hrs. I've been messing with this for an hr now and I don't even know where the start debugging this, as my program was fine yesterday.
Sample.gif is in the "icons" folder of my plugin. I've tried moving it to the src folder, and that doesn't work either.
Error message:
org.eclipse.swt.SWTException: i/o error (java.io.FileNotFoundException: sample.gif (No such file or directory))
Code (when I remove this line and all lines of code that use testImage, the plugin runs again):
Image testImage = new Image(null, "sample.gif");
Anyone have any idea what could possibly be causing this, or what information i can provide for someone to give me a direction as to how to debug?
The problem is most likely to do with where the current directory is. When you use a pathname like "sample.gif", the normal behaviour when opening the file is to look in the current directory. If you run the application with a different current directory, the application will look for the file in a different place.
I'm however confused by the current directory concept
Here are some pages that describe the concept:
http://en.wikipedia.org/wiki/Working_directory
http://www.linfo.org/current_directory.html
where should the pictures go?
If you are only ever going to run your application from within eclipse, then you can put them anywhere ... and make sure that your application's Eclipse launcher configuration sets the current directory to a consistent place. (Your current problem is most likely due to the application launcher using the parent Eclipse's current directory, and THAT may depend on where you were when you launched Eclipse ... see linked pages above.)
If you are going to export the built application in some form so that users can use it outside of Eclipse, then the answer depends on the nature of the application and how it will be installed on the user's computer. (On possible solution is to put the images into the application's JAR file, and locate them via the classpath using the ClassLoader.getResource methods.)
Related
I'm currently working on a Java project in which I have to open files I stored in a data directory next to src.
When I launch my program from Eclipse, to access these files: I type "data/fileName" whereas when I use console I have to type "../data/fileName".
(I couldn't manage to execute java src/Main from project directory and got the error :
Error: Could not find or load main class src.Main.java
Caused by: java.lang.ClassNotFoundException: src.Main.java )
Is there a way to make my program runnable on both console and Eclipse?
To give some context: I usually intended to run only on Eclipse but I encountered issues launching nano from Eclipse ($TERM variable , redirecting pipes to dev/tty also) so console execution has become a requirement.
I can't change my Eclipse configuration since this project won't be run on my computer and if it doesn't run because of default Eclipse settings, well...
Thank you for your replies.
Cordially.
Yes. Don't put those files there. There are 2 broad categories:
Read-only data that is as much a part of your app as your class files are. Think 'list of US states for the 'state' dropdown', 'an icon png to be shown on my user interface', 'a file containing a bunch of SQL to be used to initialize an empty database', and more.
For this, the proper way to go is YourClass.class.getResourceAsStream("foo.txt"), which will give you an input stream for reading the file "foo.txt", which is in the same place "YourClass.class" is. Even if it is in a jar file, for example.
This does mean that as part of your build, these files need to be in the jar. eclipse's limited build system does this. If you level up as a programmer and use a build system (you should be levelling up here), put them in src/main/resources and the build system should take care of it.
Or, the second category: Files that the user is supposed to edit, or files that need to be modified by your app.
These don't go anywhere near your jar file; executable and user-editable stuff should be nowhere near each other. These should be in the user home dir, you can fetch it with System.getProperty("user.home").
Note that to run java stuff, 'src' shouldn't be part of the story at all, java can't run source files, only class files. Also, the argument isn't a dir, it's a class name. java -cp path/to/your/app.jar com.foo.pkg.YourClass is how you run java code, not java src/Main.
I need to provide a settings file for my program, to which the user should have access to write some of the settings i need.
I created a file under a new directory (called settings) on the root of my application, but i have problem finding it at run time.
I use
File SettingsFile=new File(ClassLoader.getSystemClassLoader().getResource(".").getPath()+"settings/CreateSettings.txt");
When i execute this under eclipse i get
/application/home/dir/target/classes/settings/ZipCreateSettings.txt which is wrong.
If i execute it on terminal using java -jar, i get the correct path,
/application/home/dir/settings/ZipCreateSettings.txt
This would cause me problems cos i need to run the application directly from eclipse and not use the terminal, even though it is going to be executed using the jar when it is up and running.
I cant keep it like that anyway, cos this code might end up in someone else's hands, and they would have no idea what to do with it.
I have also used some other techniques like
new java.io.File("").getAbsolutePath(); but this always gives me the current working directory, so if i execute the jar from /home, i would get /home.
I think the problem might be maven (which i am not familiar with at all) since my code worked with a plain java application some time ago.
Since your file will be located outside your classpath, it is basically outside your application. Your application is not aware of files existing outside it's classpath. So you will need some kind of way to provide the Full/Absolute path to your file. You can't use the classloader in your case.
I suggest you use a system param instead of a hardcoded value. See here
(4/15/2014 Still no working answer to the question)
I used gdx-setup-ui.jar to create my Android/Desktop/HTML5 program which I imported into Eclipse.
myprogram
myprogram-android
myprogram-desktop
myprogram-html
My program runs fine on desktop and android, but when I run it as html I get an error if all of my classes are not in the same myprogram>src folder, if I put it in a sub folder in src then the html5 does not seem to access the class. If I take my classes out of the folder and put them in the root of myprogram>src they work. How can I fix this?
I also notice that when I do a symbolic link to the asset folder manually(without gdx-setup-ui.jar) my Java application will not find the pictures etc unless I physically copy the asset folder twice. I made sure the folder path was exactly the same and it still wouldn't detect it unless I made a second copy of the pictures. Strangely the gdx-setup-ui.jar does this symbolic copy and yet it works for some reason.
This tutorial explains how to do it in Eclipse. And for completeness sake, here is how to do it using ant and IntelliJ. I hope this was useful. I will try the Eclipse one now...
I am working on Java project (A terraria like sandbox game) and I have come across something that I just don't understand. I have been exporting the project as .jar's as I go along to upload and share with my friends, but the last time I did this, the .jar won't run, but when I run it in eclipse, it runs fine. When I try to run the jar all it does is lose focus on the explorer window for a split second, then goes back. I have tried many things, like changing the main class, changing the META, and moving the files to specific packages, but nothing is working.
The project is 9 classes, so I won't paste all the code for it here, but the latest, non-working source code can be found here (http://www.mediafire.com/?fiw6wq73j7cff4t), the non-working jar here (http://www.mediafire.com/?bhjo162oh3hi2j9), and the working jar here (http://www.mediafire.com/?h918s8xpyxw4psr). If someone with more experience in java could please take a look at this it would be much appreciated.
One of the things I tried was not adding the JPanel (the game), and just leaving the splash screen, and the jar worked. This shows that it must be a problem in the coding somewhere.
Thanks for the time,
I.D.
Couldn't find message comes from your ReadMap class. So check which circumstance leads to this error. Most likely you did not add all classes or other files to your JAR, so file is not found. Check that all needed files are added to exported JAR in Eclipse export dialog. It's also a good idea to provide more debugging info (stacktrace is ok), especially when you are studying. BTW, cool game :)
I have a problem while runing my application in eclipse. I make some edits like this:
String res = "newvalue";
System.out.println(res);
But when I run the application I still receive "oldvalue" in output. After this I tried to delete main() function - and I run application and I see "oldvalue" in output again.
Maybe it's some cache in JVM, or smth. else?
UPD:
It's 15:35 on my clock now. But in /bin folder I see .class files with 14:33 timestamp. I change source files (.java), press ctrl+f11 in eclipse and files in /bin folder are still 14:33 ...
UPD2:
After cleaning the project I receive the following problem:
The project was not built due to "Could not write file: D:\projects\NelderMead\bin\ru.". Fix the problem, then try refreshing this project and building it since it may be inconsistent
SOLUTION
The problem was that eclipse can't write file to the folder with spaces and UTF chars in it's name. So, I copy project to the new clean workspace and it runs without problems! Thx all for help detecting the problem!
You're executing an older class files, the reason could be
a compile error somewhere else (see problems view)
or your changed accidentally the source path so that the new source no longer gets compiled.
Try to clean the project and make sure the new classes are compiled to your output folder.
The JVM doesn't have a cache for class files.
First, make sure the file is saved (there is no asterisk next to the file name in the tab). Usually files are saved automatically, but you could choose not to save files and never ask by mistake, the first time Eclipse pops up this dialog.
Then see what's going on in the Problems view. You might see something like project cannot be built due to the following reason. It may be because of compilation errors in the dependent projects.