Home » Tag Archives: JVM (page 2)

Tag Archives: JVM

Looking at DiagnosticCommandMBean in JConsole and VisualVM

I’ve used JConsole for many years as a suitable generic JMX client. This tool is generally available with the Oracle JDK and is easy to use. In terms of JMX interaction, the most significant advantage of JConsole over VisualVM is that JConsole comes with a built-in MBeans tab while a plugin must be applied for this same functionality in VisualVM. ...

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Printing arrays by hacking the JVM

Overview One the most common gotchas in Java, is knowing how to print arrays. If an answer on how to print an array get more than 1000 upvotes, you have to wonder if there is a simpler way. Just about every other popular language has that simpler way, so it’s not clear to me why Java still does this. Unlike ...

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Default HotSpot Maximum Direct Memory Size

In my previous blog post Improved Documentation of HotSpot Options in Java 8, I wrote about the misunderstandings surrounding the HotSpot JVM‘s default setting for non-standard option -XX:MaxDirectMemorySize. In this post, I look at a simple way to determine the “default” maximum direct memory size in the HotSpot JVM. The Java 8 documentation for the Java launcher states the following ...

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Simplicity and Value of HotSpot’s -XshowSettings Flag

A handy HotSpot JVM flag (option for the Java launcher java) is the -XshowSettings option. This option is described in the Oracle Java launcher description page as follows:                 -XshowSettings:category Shows settings and continues. Possible category arguments for this option include the following: all Shows all categories of settings. This is the default ...

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Improved Documentation of HotSpot Options in Java 8

One of the small but welcome features introduced with Oracle’s HotSpot implementation of Java 8 is the addition of many common HotSpot Java launcher (java) options/flags to the launcher’s documentation. In the past, a developer interested in even some fairly common HotSpot JVM options has had to potentially look in multiple different sources to find “official” documentation on these flags. ...

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Introducing Cucumber for Java + STANDARD Values

As software developers, we all have our favorite tools for making us successful. Many are perfect for the job when getting started but are soon outgrown. Others require too much setup and training to “dip your toes in the water” just to simply find out if they are the right tool. Cucumber JVM is a testing framework that enhances JUnit ...

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