Explicit specification of the timestamp for a JNLP file, i. Supports all download protocols defined in the JNLP specification v1. This include basic download protocol, version-based download protocol, and extension download protocol. Version-based information is specified per file or per directory in the Web archive.
|Published (Last):||13 February 2012|
|PDF File Size:||17.78 Mb|
|ePub File Size:||15.19 Mb|
|Price:||Free* [*Free Regsitration Required]|
How can I launch Java Web Start from the command line? The JNLP 1. This restriction avoids requiring the user to accept multiple certificates from the same source, and enables Java Web Start to know if the user has accepted all certificates used for an application.
The only requirement is that the JAR files contain code from different packages. The steps for doing this vary depending upon the web server you are using. Furthermore, if your corporation uses a proxy server, ensure that the update versions of the files are returned, by updating the time stamp of the resources on the web server such that the proxies will update their caches. If you deploy yourfile.
Back to top What is the best way to ensure only one instance of my application is run? Use the SingleInstanceService to register as a singleton as soon as your application starts up. Re-invoking your application before it is registered as a singleton will cause another Java VM to start up. Make sure to unregister before your program exits. Back to top When will properties set in the jnlp file get set?
Normally, properties in the jnlp file will not be set until the first resource listed in that jnlp file is loaded. This insures the properties are set before any of your code is run, however some properties need to be set before other packages are loaded. This problem is specific to Internet Explorer. Although this can be caused by a full cache, or turning off the cache in IE, it is usually caused by a no-cache directive coming from either the web server or the proxy server.
IE will honor this directive, and not write the jnlp file to disk, so Java Web Start cannot find it. This frequently happens when upgrading a tomcat based server. Later versions set the no-cache directive by default for any resource that is within a security-constraint in web. Try taking the relevant URI out of the security constraint in web. Beginning with Java Web Start 1. The association feature specifically requires libgnomevsf If this library is not present, associations are not supported.
Back to top How do I set up my server to broadcast the jnlp mime type? Each web server has a specific way in which to add MIME types. For example, for the Apache web server you must add the following line to the. See the Developers Guide section on configuring the servlet. The application need not be packaged in a Web Archive. Back to top How are Applications uniquely identified?
If multiple applications share the same main jar file, they must contain an href, or they will be treated as the same app. In version 1. The Viewer can only launch an application online, if it has an href. The same thing applies to creating shortcuts. Also, both the file-extension and mime-type must be specified for each association tag.
Security is a key consideration of the Java Web Start design. In Java Web Start all applications are launched by default in a secure "sandbox. Applications in the secure sandbox have restricted access to local computing resources such as the disk and network.
Back to top How is the Java Web Start secure sandbox more flexible than the applet sandbox? All applications, by default, are run in a sandboxed environment, similar to the applet sandbox. The API includes dialog boxes for operations such as saving a file and opening a file that are actually rendered by Java Web Start, and not by the application itself.
This sandbox design is similar to what you can do with HTML. Back to top How can I enable my application to gain unrestricted access to the system? An application requesting unrestricted system access must be digitally signed. The first time a user launches such an application, a security dialog box will appear. Before running the application, Java Web Start will prompt the user to accept the digital certificate.
After the user has accepted the certificate, subsequent invocations will not show the security dialog box. Back to top Is there support for encrypted download of JAR files? Support for encrypting data transferred from the server to the client is very important. This is an important point on our issue list, and we will definitely make sure that HTTPS libraries will work with applications that are launched with Java Web Start.
The HTTPS support might be in an optional package that you need to specify that your application depends on. Encrypting the JAR files transferred from the server to the client may not be necessary. The reason is, even if the class files where encrypted on the wire, they will have to be decrypted on the client side and stored to disk, so the JVM will be able to load the classes. Thus, it could be fairly simple for a cracker to get around the encryption of the JAR files. Instead, what is important for JAR files is that they can be signed, so the user can be absolutely sure that the application is from the vendor he expect it to be from.
This is already supported. NTLM support was added to Java 1. It is recommended to use at least Java Web Start 1. Are there other online resources to learn more about the security tools? See the following:.
Java Network Launching Protocol and API Specification Change Log
Section 2: Request 2. An implementation of this specification will support web deployed applications by enabling distributing an application on a web server and launching the application from a web browser. The components of this infrastructure are likely to include: A standard encoding of the information needed to launch a Java application whose components are hosted by one or more web servers. A launcher application, such as a browser helper application, that interprets the above encoding and launches Java based applications. Browser helper applications are associated with a mime type and default file extension. This specification will define a mime type and default extension for the above encoding.
Frequently Asked Questions (FAQ)
How can I launch Java Web Start from the command line? The JNLP 1. This restriction avoids requiring the user to accept multiple certificates from the same source, and enables Java Web Start to know if the user has accepted all certificates used for an application. The only requirement is that the JAR files contain code from different packages. The steps for doing this vary depending upon the web server you are using. Furthermore, if your corporation uses a proxy server, ensure that the update versions of the files are returned, by updating the time stamp of the resources on the web server such that the proxies will update their caches.
Packaging JNLP Applications in a Web Archive
Samumi Can be used in an extension element to denote the parts contained in a component-extension. By default they run in the same sandbox as applets, with several minor extensions like allowing to load and save the file that is explicitly selected by the user through the file selection dialog. As no permissions are requested, the code will run in a sandbox. This table does not include all possible contents of the JNLP file. Only one description element of each kind can be specified. The check attribute indicates specificattion preference for when the JNLP Client should check for updates, and can have one of the three values: Description elements are optional.