Java Web Start Flashcards
Where does a Java program run with Java Web Start?
JWS runs the JVM locally on the user’s computer and then runs the application within the JVM; it doesn’t use the user’s web browser env.
What was the issue with applets?
Though applets allowed Java programs to run on browser, they required browser plugins. Using too many different browser plugins caused compatibility issues.
What cannot apps running Java Web Start do?
reading and writing files; accessing user’s local network
What is the general process for setting up an app to run with JWS?
1) create a JAR file that contains the java app you want to run with JWS
2) create a JNLP file that specifies the necessary info to enable the program to run from JWS; the JNLP must have the location of the application’s JAR file (e.g.: ClickMe.java -> ClickMe.jar -> clickme.jnlp)
3) create an HTML file that contains a link to the JNLP file; the HTML will appear in the browser and will send you to the JNLP file when its link is clicked, and the app is run
4) copy the JAR, HTML, and JNLP files to the appropriate folders on the web server; FTP clients like FileZilla can upload files to your web server
What is a JNLP file?
JNLP = Java Network Launch Protocol
A JNLP file is a small XML file that contains info like the name of the app, a URL that points to the app’s JAR file, the vendor who created the app, the java version required, and a URL.
A JNLP can be used to download Java runtime in case it isn’t installed.
How many files does a simple JWS application have?
at least 5 files:
.java, .class, .jar, .jnlp, and .html
Sometimes Java’s security settings will prevent a JWS app from running. How can you get around this?
The user can add the URL of the application to the Java Exception Site List.
What are the steps to add the URL of a JWS application to the Java Exception Site List?
Control Panel -> Find “Web Settings” -> Click “Add” -> Type the URL of the web site (e.g.: lowewriter.com) and press “enter” -> Click “OK” to close Control Panel
