Javadocs on java.text.SimpleDateFormat state the following on the "z" pattern letter: z Time zone General time zone Pacific Standard Time; PST; GMT-08:00 General time zone: Time zones are interpreted as text if they have names. For time zones representing a GMT offset value, the following syntax is used ... Question ...
I want to know the internals of the JVM, how it performs and the details that matters. Can you suggest any resource or best book available for this ?? ...
I recently changed network and removed all my HTTP proxy settings from the System Preferences / Networking panel on OSX (Leopard). However, now whenever I use Eclipse the Java HTTP proxy system properties seem to be 'automagically' set to use my now defunct HTTP proxy. I can find no direct reference to this proxy anywhere on my system, ...
Where do you seen using Scala for your project? ...
Is there any site/analysis about what Java version most people are using on WWW ? It seems this data is not available on webserver logs (vs. Flash versions) Can we safely set e.g. Java 1.4.2 as minimum requirement for our applet, or are there still many users using Java 1.1 (MS one) or Java 1.2-1.3 ? It's still a bit of a complicated p...
I'm dealing with the same sort of problem as "Zombie http.proxyHost settings for JVM on OSX" except I'm on Kubuntu 8.04 and Eclipse 3.4.2. I had to use a proxy for work but have migrated off it. I've reset everything in my environment I can find inside and outside Eclipse to get rid of setting the proxy. However when I try to use the Sof...
A backend webapp is deployed on a Tomcat 6 servlet container. In the webapp, several monitoring threads are started. The problem is with shutdown. How do I know that the webapp is requested to shutdown? How should I handle this in my threads? Currently my thread is implemented as below. When the servlet is instructed to shutdown (sh...
At work, we've been having a problem with "PermGen out of memory" exceptions, with the team lead deciding it was a bug in the JVM - something related to hot-deployment of code. Without explaining many details, he pointed out that hot deployment is a "hard problem", so hard that even .NET doesn't do it yet. I found a lot of articles expl...
Alan Kay points out that "Unlike Java, [Squeak] runs bit-identical on every machine -- we invented this 20 years ago". The wikipedia page mentions this also: Squeak is available for many platforms, and programs produced on one platform run bit-identical on all other platforms. Since machines with different instruction sets ob...
In our web apps the first load of some pages takes a small but noticeable extra about of time due to class loading. Does anyone have any clever ways of preloading web app classes in the JVM on start up? Update: What we do now is store a bunch (700) of full class names in a db table. We read the table at startup and do Class.forName()...
Since both the java implementation (OpenJDK) and Android's virtual machine DalvikVM are opensource it must be possible to implement Sun's JavaVM on top Google's DalvikVM. This would make it possible to run JVM based apps and languages (Clojure, Jython) out-of-the-box on the android. Is there an ongoing effort to produce such an implemen...
Hi, Is it possible to specify the JVM to use when you call "java jar jar_name.jar" . I have two JVM installed on my machine. I can not change JAVA_HOME as it may break code that is all ready running. Kind Regards Stephen ...
Hi all, I have a question regarding the JVM memory management (at least for the SUN's one). I would like to know how to control the fact that the JVM send the unused memory back to the OS (windows in my case). I wrote a simple java program to illustrate what I expect. Run it with -Dcom.sun.management.jmxremote option so that you can a...
I've written a Thrift server in Java to take advantage of a specific Java package/library, but I'm not a java programmer. The problem is; I'm seeing a time-out for the first RPC call to the server. Subsequest requests are executed without any issues, and its only affecting clients written in certain (but essential) languages. My curre...
Is anyone attempting to implement C# for the JVM? As a Java developer, I've been eyeing C# with envy, but am unwilling to give up the portability and maturity of the JVM, not to mention the diverse range of tools for it. I know there are some important differences between the JVM and CLR but is there anything that is a showstopper? ...
I'm evaluating between open source and closed source JVM for ARM. In particular, the closed source JVM can make use of Jazelle (java acceleration for newer ARMs). Do you have any experice with this technology? (And BTW, which OS do you use with it?) ...
Hi I used to generate thread dumps by running kill -quit and I would get them in a log file where my server logs were there. When the file grew too large I removed it using rm and created a new file of the same name. Now when I use kill -quit to take the thread dumps, nothing gets copied in the log file - its empty. Can anyone help? ...
Hi! A great feature - I think - is, when languages, running in a virtualized way like C# and Java show errors during you're working on the source. Most often IDEs like Eclipse or NetBeans or VisualStudio have the feature to specify errors immediately. Is there anything like this for C/C++? Just for coding... I'm currently searching for...
I've got a Grails application that does a fairly decent amount of domain object creation and destruction, and it seems to run out of PermGen space at a very, very rapid rate. I've done the usual tweaks (bumped PermGen to 256M, enabled class GC, etc.), but no dice. Would anyone care to recommend some (and hopefully free or very low-cost...
I am seeing all these new languages for .NET and JVM. How does one begin to make one? I can't find any good documentation on JVM or MSIL specifications. Edit I already know how to parse, I am more interested in how there are so many people making new languages that are based on those platforms. ...