A question about the Book of Vaadin: in chapter 4.4.3. Class Loader Resources:
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The
ClassResource allows resources to be loaded from the class path using Java Class Loader. Normally, the relevant class path entry is the WEB-INF/classes folder under the web application, where the Java compilation should compile the Java classes and copy other files from the source tree.
The one-line example below loads an image resource from the application package and displays it in anImage component.
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layout.addComponent(new Image(null, new ClassResource("smiley.jpg")));
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So in this example the image
WEB-INF/classes/smiley.jpg is used, am I right?
But, if so, why it doesn’t work in my code? This is it:
// Image as a class resource (i.e. inside WEB-INF/classes)
Resource r = new ClassResource("image.png");
layout.addComponent(new Image(null, r));
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image.png is an image inside WEB-INF/classes dir (I have created the classes dir inside WEB-INF and put the image.png image inside that directory), so it should work, but it doesn’t. Why?
Yes, I guess I have exported the project to the web application archive by selecting the project and clicking “Run as → Run on Server” and the project is deployed to the eclipse’s home/workspace/.metadata/.plugins/org.eclipse.wst.server.core/tmp0/wtpwebapps/my_project/ path and inside this path there’s the WEB-INF/classes directory with the image.png file, I have checked that.
And still I don’t see the image, what should I do?
Ok, thank you for the elucidation, I have tried what you are saying:
Export → WAR file , saved the .war file inside Tomcat’s webapps dir, restarted Tomcat, checked Tomcat’s webapps/ folder and the project is there (un-wared), opened the browser, but yet I can’t see the image… How is that possible? Could it be something else?
so what i did ?
i just add this line as button event :
button.addClickListener(e -> myImage.setSource(new ClassResource("../resources/myImage.png")));
look at the path … “…/resources/myImage.png”
why i point to parnet folder using “…” … i don’t know what i call them " maybe double dot’s" ?
screen shoot from my pc → look the atachment files
}
else if ( yourProjectStructure != maven ) {
maybe ant + ivy … ( create it with eclipse plugin ) …
you need to know ClassLoader refer to where is your main class is main class is where you define this code
As Vikrant said, the app must be exported to a WAR archive and then deployed to the Tomcat server. Anyway, the image must be located in the same directory, where the compiled UI which uses it is located (in my case it was WEB-INF/classes/com/example/project).
