How to load a file on the server side

Vaadin 6 / 7 / 8
1

Hi,

When i want add a little image into a button, i use this code which works fine :

mybouton.
setIcon
(new ThemeResource("…/my_theme/myImage/fr.gif "));

But Vaadin needs to know the first part of the path, which is missing here, in order to locate the resource.
So, how Vaadin gets the path which is before …/my_theme/myImage/fr.gif ??

the
setIcon
 meythod belongs to the AbstractComponent class, the source code is here, but i don’t see any explanation about it :

AbstractComponent source code


Vaadin javadoc

Could someone explain where the first part of the path, comes from ?

Eric

2

Hi,

The theme resource path is relative to the path of the current theme. The theme path is [tt]
VAADIN/themes/themename
[/tt] under the web application content. When deployed, the complete URL to the [tt]
styles.css
[/tt] file of a theme would be, for example, [tt]
http://localhost:8080/myproject/VAADIN/themes/mytheme/styles.css
[/tt].

You can use relative paths to point to resources in other themes.

The ThemeResource is probably best documented in
its book section
 and
its example
. It’s also mentioned in the API documentation for
setIcon()
.

3

Thank you Marko,

I need to load a csv file named “eric.csv” into a BufferedReader.
This file is located here : WebContent / VAADIN / themes / eric_theme

If i use the following code, i use the path of this file, but do not know how to get it.

BufferedReader input = new BufferedReader( new InputStreamReader(new FileInputStream(pFilePath), “UTF-8”));

From your point of view, what is the best way to load this file ?

Eric

4

You should normally not put application data files in the theme folder, as they can be read by browser and are therefore a security risk. The WEB-INF folder is a safer place.

You can get the base directory in which the application is deployed with:

String basepath = getApplication().getContext().getBaseDirectory().getAbsolutePath();

The WEB-INF folder would be basepath+“/WEB-INF”, the themes would be in basepath+“/VAADIN/themes/mytheme”, and so forth.

You can also put static data files under the WEB-INF/classes folder and then read them with the Java class loader.

Notice that
non-static data
 should not be kept anywhere in the web application, as redeploying the application would cause deletion of the data, depending on the web server.

5 

public class Launcher extends Application{
     public void init() {
          [color=#14a235]
ApplicationContext context = this.getContext();
[/color]
	  if (context instanceof WebApplicationContext) {
       	          System.out.println("Path to WEB-INF : "+[color=#14a235]
context.getBaseDirectory().getAbsolutePath()
[/color]);
	  }
	final Window mainWindow = new Window("Myproject Application");
	setMainWindow(mainWindow);
	mainWindow.setSizeFull();
	mainWindow.addComponent(new WindowOpener("Window Opener", mainWindow));
}

I compile this code inside Eclipse from this location :

C:\DEV\Workspace_Vaadin\myVaadinProject
 , and i get this strange path with
.metadata
 :

C:\DEV\Workspace_Vaadin

.metadata

.plugins\org.eclipse.wst.server.core\tmp2\myVaadinProject

which contains WEB-INF and compiled classes.

I tried to put my csv file into

C:\DEV\Workspace_Vaadin\myVaadinProject\WEB-INF
,
and after running the project, the file was loaded and copied into

C:\DEV\Workspace_Vaadin

.metadata

.plugins\org.eclipse.wst.server.core\tmp2\myVaadinProject\WEB-INF

So it is a strange behaviour, but it works fine.

Thank you Marko :slight_smile:

6

Yes, when you deploy the project to a server in Eclipse, it deploys the project to such odd location.