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Question: In a link that is to run a Java Web Start application, which file is specified as the a tag's href attribute?
Answer: You use the application's JNLP file name as the value of the href attribute. When a user clicks the link to the JNLP file, Java Web Start loads the application specified by that JNLP file.
Question: Which MIME type must a Web server recognize in order for it to host Java Web Start applications?
Answer: You must configure the Web server so that files with the .jnlp extension are set to the application/x-java-jnlp-file MIME type.
Question: In an application's JNLP file, which two elements must be specified within the resources element?
Answer: The resources element must contain:
j2se element, which specifies the Java platform on which to run the application.jar element, which specifies the JAR file for the application.Question: Which interface provides the ability to an application to control how its own resources are cached?
BasicServiceDownloadServicePersistenceServiceExtendedServiceAnswer: B. The DownloadService interface provides the ability to an application to control how its own resources are cached.
Question: True or False: Java Web Start applications run in a secure sandbox by default.
Answer: True.
Question: True or False: If a Java Web Start application is running in a secure sandbox, JAR files for the application can reside on different servers.
Answer: False. All JAR files for the application must reside on the same server.
Question: For a Java Web Start application to support operations outside of the secure sandbox, what must you do with its JAR files?
Answer: You must sign JAR files to enable your application can work outside of the sandbox.
Exercise: Write the XML code you would add to a JNLP file in order to request that the application have complete access to the client system.
Answer:
<security> <all-permissions/> </security>
Exercise: For a Java Web Start application, you have two icons, one.gif and two.gif, in the images directory in a JAR file. Write the application code you would use to access these images.
Answer:
// Get current classloader
ClassLoader cl = this.getClass().getClassLoader();
// Create icons
Icon firstIcon = new ImageIcon(cl.getResource("images/one.gif"));
Icon secondIcon = new ImageIcon(cl.getResource("images/two.gif"));
