Running the Web App Hello World! on a Raspberry Pi gives the error in the web browser:
HTTP ERROR 404
Problem accessing /. Reason:
Not Found
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Wherever your WebAppHelloWorld.jar file is located, there also must be a www directory with the three files (b4j_ws.js, index.css and index.html) inside of it. Without the www directory, you'll get the above error and without the 3 files, the example will not run as expected. In the example .zip file, the www folder is located under the Objects folder.
The b4j-bridge.jar on the Pi box should (when executed) create a tempjars folder. It is within that folder that you need to place the www folder and its contents.