Loading image from a Java file - java

I have this project structure:
ProjectName
src
xxx
co
com
package
something.java
web
image
print
pic.jpg
I want to load the pic.jpg in the java file which will then be used in the pdf file generated. I have gone through the answers here but, nothing helped me yet. Possibly I am missing a small thing.
If the pic.jpg was under package, then getClass().getResource("pic.jpg") works absolutely fine. getClass().getResource("/web/image/print/pic.jpg") doesnt work as well. But I want to place all my images under image folder and refer it in the java file.

You should get the application runtime path and rebase the path to the folder which images locate.
You can use the code:
String path = new File(".").getCanonicalPath();// or System.getProperty("user.dir")

Seems your files are not copied to bin/ directory. Change your build script to copy them to output directory
getClass().getResource() will use class loader to load class, since those files need to be in classpath

Related

Images not loading after creating Jar

im wring a simple program and my images load in fine in the project but as soon as i export it into a jar file none of them load. i have little to no experiance creating artifacts or jar files.
project structure:
project:
src:
myclass1, myclass2...
res:
image1.png image2.png...
im using Toolkit.getdefaultToolkit to load in images
in my class i am loading the images in the constructor by writing
myImage = toolkit.getImage("res/image1.png");
this works perfectly fine in the project. does not work in the jar
i have also tried
myImage = toolKit.getImage("image1.png");
which does not work in the project or while opening the jar
i know toolkit is not the best way to go about loading images but i would like to know how i can fix this issue while using toolkit.
ive even tried using the absolute path to a folder on my desktop and once again they load in fine in my project but they do not get loaded when opening the jar. please help ive tried everything. thanks
(btw) if i open the jar file in intellij the images load but if i open the jar file in finder or from my desktop they do not. i want to be able to send the finished project to someone
The toolkit.createImage(String) method takes in a string, and interprets it as a path, looking for a file at that path. An entry in a jar file is not itself a file. It is therefore impossible to use this method to read image files that are in a jar.
However, that's not the only createImage method. There's also toolkit.createImage(URL) and that is the one you want.
SomeClass.class.getResource("something.png")
This expression works on any class (Foo.class gets you the class instance for Foo, and all class instances have the getResource method), and will look for the named entry in the exact same place SomeClass.class (the file) lives. If SomeClass.class currently lives in a jar file, then that's where it'll look.
Thus, ensure that img.png is in the same place your class file is (ensure it is jarred along with the rest), and that will work. You can also ask for e.g. SomeClass.class.getResource("/foo/bar/img.png"); this will then look from the 'root' of where SomeClass is. So if you have a jar such that if you run jar tvf thatjar.jar and you get:
....
/com/foo/yourpackage/SomeClass.class
....
/foo/bar/img.png
then /foo/bar/img.png works.
thus: Once you know where you put that stuff in your jar file:
toolkit.createImage(YourClass.class.getResource("image1.png"))
is what you're looking for.

Find a resource both in .jar and eclipse with the same String computation

I want to get the path to a resource for ImageIO to read out a BufferedImage from some .png s.
While developing the project I use a relative path to "/bin/stuff/icons/image.png" , but this will definetly not work when I put everything together into a .jar file, so I need a way to get the path to these resources both while testing in eclipse and when later running it within a .jar .
After a lot of trying out both finding the file and getting the input stream to the file I came to the conclusion that this approach works every time:
InputStream in = ClassLoader.getSystemClassLoader().getResourceAsStream(path)
BufferedImage image = ImageIO.read(in)
Where path is
"projectName/resourceFolder/" + nameOfResource.stuff
as found in the src directory of the eclipse project.
E.g.
"myProject/images/icon.png"
When getting only the resource and then getting the path of the resource to link to a file, you will get FileNotFoundExceptions when using a .jar (but not while testing with eclipse, so one should be warned to think that his code works).
And - no - I don't save images in the bin/ - but they are copied to this directory and thus I find them there while testing. Now everything seems to be working.
Don't put anything under the bin directory in Eclipse: if you run a clean on the project it will be erased.
What you can do is to define a new source folder like resources, and put the image there. This way it will be automatically copied to the bin folder.
If you include the resources folder into the Jar, it will be available in both environments by using something like:
ImageIO.read( getClass().getResource("/image.png") )
PS: You can evade using a different resources folder but mixing the sources and images will quickly pollute your source folder.

How to fix this java.io.FileNotFoundException?

I'm trying to load a .csv file in a program but for some reason, it's unable to find the file. Where should I place the file?
Console
It looks like the file is in the src directory... which almost certainly isn't the working directory you're running in.
Options:
Specify an absolute filename
Copy the file to your working directory
Change the working directory to src
Specify a relative filename, having worked out where the working directory is
Include it as a resource instead, and load it using Class.getResourceAsStream
The file is located in the src directory so in order to access it you should use
src/Elevator.csv
As long as files are located inside your project folder you can access them using relative paths.
For example if a file is located under the Elevator folder then you access the file by using only its filename.
Elevator.csv
A good principle when using additional files in your project is creating separate folders from the ones that the source files are located. So you could create a folder resources under the project folder and place your file there. You can access then the file by using
resources/Elevator.csv
the path which it is trying to read is surely not exact as the path in which that file is actually present.Try printing absolute path of that file and compare it with actual path of your file.
I tried with all the above mention solution, but it didn't work..
but i went to my project folder and delete the target and tried to compile the project again. it then worked successfully

cannot locate properties file in java path

My code cannot locate the .properties file where i have stored login information.
I have put the file in the src folder to make sure it compiles, and it does correctly.
below is the current location of the file and how i am trying to access it.
I have tried various different paths but no luck.
Change your code;
ResourceBundle bundle = ResourceBundle.getBundle("Selenium/readme");
to
ResourceBundle bundle = ResourceBundle.getBundle("readme");
You don't compile a .properties file, you use it as is.
If you use a FileInputStream it will use the working directory which is set in your Run configuration (most likely the top directory)
But you are loading it as a resource which means it must be in your class path. The simplest thing to do is to create a sub-directory for your configuration and add this to your programs class path.
Read properties file like:
ResourceBundle.getBundle("src/properties/readme.properties"); //Or simply "properties/readme.properties"
Put readme.properties under src/properties directory.
you can use this.getClass().getResourceAsStream("readme.properties");
for more information read:
I see that the .properties file is not inside the src folder. Also check the build path of your project.It will show you the src folders and the output folders location. Once you build the project using eclipse build project option, make sure your properties file is now available in the output folder.

Accessing images in Java ME

I used following code to access an image from "res" folder with NetBeans
imgWelcome = Image.createImage("/cover.png");
img = new ImageItem(null, imgWelcome, ImageItem.LAYOUT_CENTER, "");
Though the resource is not getting detected and i keep on getting NullPointerException. As weird as it sounds, exactly same technique worked in my previous program.
What am I doing wrong here?
P.S. I've double checked that the file exists in the res folder
There might be many reasons for this, but I have found that most of the time, it is due to how the project is built. Some build scripts include the resources in the res/ folder as top-level files, and some include that folder as a folder in the jar file.
What I have always done to troubleshoot is to rename the jar output to zip and look inside. If the image files are contained in a folder then you should address them as such.
Your code will not find cover.png if it is in the /res folder.
Inspect the contents of your jar using 7-Zip or similar, ensure the image really is in the /res folder, then replace the first line with imgWelcome = Image.createImage("/res/cover.png");.
Oh wow.. this was because .png was not supported by my emulator. And what all I tried :(

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