Moderator (MDR): MDR-Andrea

Guest-Speaker (SPK): SPK-David

SPK-David: Fire away...

jmerk54: I heard that 1.2 will allow for more "system" type operations, port operations, and device operations. If so, would you elaborate?

SPK-David: Yes, there is a more flexible security model that allows applications and applets to access additional resources based on the configuration of a user's policy file. The new security features are described in more detail on our JDK 1.2 Beta 2 features web page (http://java.sun.com/products/jdk/1.2/docs).

majic: David. Can you give a few examples of new applications and extension features?

SPK-David: Applications in JDK 1.2 can take advantage of both installed and downloaded extensions. Through the JAR file manifest, it is possible for an application or extension to specify dependencies on other JAR files. These JAR files will be downloaded unless they have been preinstalled, in which case the installed version is used.

hamiltond: What is the likely availability of the cryptography extensions for those outside the US and Canada?

SPK-David: I'm not sure about this one. You can send email to java-security@java.sun.com and they should be able to help you out.

JamieS: I have a servlet question: There are some extensions to the servlet classes in JDK 1.2, such as Sessions, that are rather helpful. It seems that servlets have been folded into the JDK 1.2 (beta) package, and the ServletDK is no longer available separately. Do you know where I can get information about what server providers (Sun, Netscape, etc.) are supporting the enhanced (1.2) servlet classes, and what their release schedules are? I could not find this information on the servlet page. Sorry if this is too far afield.

SPK-David: There is a updated list of servers that support the servlet API on the JavaServer^TM product page. Just follow the link from http://java.sun.com/products and you should find the answer to your question there.

With the new collection classes, is this still the case, or has Vector been reimplemented so its Enumeration is the preferred method for access? Or should I skip the Vector altogether and use the newer collection classes?

SPK-David: The new collections API equivalent to Vector is Array. You can iterate through the elements of an Array object on at a time like your Vector example or use an Iterator. Both offer probably more or less the same performance. Array is generally faster than Vector, since it is unsynchronized by default.

JamieS: Will there be additional 1.2 beta releases before the final release? Do you know where I can look for an approximate schedule?

SPK-David: The 1.2 Beta 3 release is due to go out very soon now (in the next few weeks). Keep an eye on our web page for more details.

kky: Hi. In the package versioning spec, section 1.5.4 & 10 there is mention of a check of implementation version numbers. I'm just checking how this is used. Am I correct in assuming this is a property that a programmer uses to determine the current environment version and not a system property used for determining linking? For example, the dynamic linker won't use an identity check when looking at program version, but accepts a greater than or equal check for library version as usual?

SPK-David: Correct. The dynamic linker does not use the versioning information, but it is only provided as an aid to programmers.

JamieS: In the final 1.2, will there be a nice mechanism for (essentially) adding a specified JAR to your classpath, or do we still have to pilfer code from the BeanBox to implement dynamic loading of classes from JARs?

SPK-David: In the next beta release there will be a new -jar flag for both Java and JRE that will allow you to execute a JAR file either from the local disk or an arbitrary URL. The JAR

JamieS: Is there any way to change the "Current Directory"? I know that I can get this directory with the appropriate System property, and that setting the System property to a new value has no effect on the actual current directory. Is there any way to change this directory, or should we just ensure that we have complete, absolute paths for all files we use?

SPK-David: There is no standard way to change the current directory from Java. You would have to do this using native code.

jmerk54: What sort of enhancements have been made to the JDBC?

SPK-David: I'm not too familiar with JDBC. You can try the JDK/JRE 1.2 product web page and see what information has been publicized.

JoeSam: What's the approximate final release schedule at this point? I'm not looking for insde info, just wondering what the time line is for further changes or major revisions. Along the same lines, will Swing, the new JNDI and SSL API, etc. be synchronized with the release? It's a problem, for example, to have Swing 0.6 with 1.2 when 0.7 is out.

SPK-David: I can't really talk about specific release dates but with the exception of some driver APIs (i.e. extensions, 2D). The APIs are pretty much stable right now. Both JNDI and SSL are likely to be released as true extensions once JDK 1.2 is released in FCS form.

JamieS: We're developing some GUI applications, as well as some services. The services terminate (without a call to Runtime.exit) when we expect them to—when there are no non-daemon threads live. The GUIs appear to stick around after we close all windows and kill all of our threads. Rooting through the current threadgroup indicates that there are several AWT threads still live. Am I likely doing something wrong (holding onto an AWT resource I should dispose of), or is the proper way to terminate a GUI app by using Runtime.exit? Thanks.

SPK-David: I'm not very familiar with the AWT, but in general it is not necessary to call Runtime.exit() if you've closed all your threads. This might be a bug in AWT. (Is it 1.1 or 1.2?)

langley: I recently started working with the new security tools in JDK 1.2. However, I realized that there is currently no "browser environment" other than the applet viewer to test in. Is there a release of HotJava^TM or Project Java Activator coming out soon with JDK 1.2 capabilities?

SPK-David: I'm not sure about HotJava, but there should be a new Project Java Activator version based on 1.2 released soon.

jimheintz: According to JDK 1.2 beta documentation, JFC will be included with it. Will it replace the AWT completely? Will PersonalJava^TM when it migrates to 1.2 also have Swing (JFC) components instead of vanilla AWT components?

SPK-David: Again, Swing and AWT are not my area of expertise, but I believe that Swing is implemented on top of the new AWT, which also includes some new 2D features. As for PersonalJava, it's hard to say since that is a subset of the Java APIs and the 1.2 version has not been spec'd yet.

xqw: What will change in RMI? There was a rumor half a year ago saying RMI will implement CORBA? Is it true?

SPK-David: I believe that RMI is being reimplemented to use IDL as the transport layer. Other than that, I'm not sure what its future relationship to CORBA will be.

JamieS: We have noticed that we get entirely different background colors between JDK on Windows NT, JDK on Solaris/CDE, and JDK on Solaris/OpenWindows. The background on NT matches the user's setting for window background. On Solaris/CDE that seems to match the frame color (gray), whereas on Solaris/OpenWindows we get an bizarre purple from who knows where. Are there any plans to "normalize" this behavior?

Also, it is not clear what SystemColor.window is supposed to match up with in the user's desktop settings. I assume that it is supposed to be the normal window background color, but it doesn't always seem to behave that way. Is there a SystemColor that matches the frame color?

SPK-David: Again, not my area of expertise, but they have fixed a bunch of AWT-related bugs in 1.2 Beta 3, so check our website again in a few weeks to see if it has been released.

glv: Are you familiar at all with the new printing API in JDK 1.2? I've been trying to figure it out, without a lot of success (the documentation is sparse, and everything's an interface, with no source code to explain what's going on). I'd like a brief outline of how to use the Book class and Printable interface to print a document that spans multiple pages.

SPK-David: I'm not familiar with the new printing API, but I do know that it's one of the drivers for 1.2 Beta 3. So check again once that is released to see if the documentation has been improved.

JamieS: (I think I was a little unclear with my JAR question earlier.) If I wish to specify a JAR to load while my program is running (it has dynamic extensions, or is a GUI application builder, or some other reason), what is the best approach to load these classes? Is it still best to dissect and reimplement portions of the BeanBox to get dynamic JAR loading?

I do appreciate the -JAR option that you mentioned earlier as a JRE command-line option—that's a good idea. It just addresses a slightly different issue. Sometimes it is not known until the Java is already running what JAR(s) we want to load.

SPK-David: OK, there is a new class in 1.2 called java.net.URLClassLoader that extends java.lang.ClassLoader with the ability to dynamically load JAR files and classes from arbitrary URLs. You probably want to look at the documentation for that class, as it would allow you to load JAR files in new class loader's on the fly.

jmerk54: David, of the features in 1.2, which would you say offer the most benefit over 1.1x?

SPK-David: There are a whole bunch of improvements in 1.2 over 1.1. It's hard to say which are the most beneficial as it completely depends on what types of applications you are developing, but Swing is certainly one of the major improvements.

Andrea: Well, our time has run out. Thanks to everyone for joining, especially David. Be sure to join us next week, for a discussion of PersonalJava with engineer Curtis Sasaki. Take care and see you all next time.

JamieS: David & Andrea: Thanks for the information!

Andrea: You're welcome.