#JAVA MEMORY DISK MAP CODE#

Prevention : When the OutOfMemoryError due to PermGen exhaustion is caused during the application launch, the solution is simple.

#JAVA MEMORY DISK MAP CODE#

Running the above code will keep generating new classes and loading their definitions into Permgen space until the space is fully utilized and the : Permgen space is thrown.

Split() String method in Java with examples.Types of Exception in Java with Examples.Flow control in try catch finally in Java.Nested try blocks in Exception Handling in Java.Output of Java program | Set 12(Exception Handling).Infinity or Exception in Java when divide by 0?.Throwable printStackTrace() method in Java with Examples.Throwable getStackTrace() method in Java with Examples.Class isInstance() method in Java with Examples.instanceof operator vs isInstance() Method in Java.new Operator vs newInstance() Method in Java.Different Ways to Print Exception Messages in Java.Understanding OutOfMemoryError Exception in Java.ISRO CS Syllabus for Scientist/Engineer Exam.ISRO CS Original Papers and Official Keys.GATE CS Original Papers and Official Keys.Using -Xmx512m is a valid option, but -Xmx0.5g will cause an error. Your setting won’t work if you specify “MB” or “GB.” Valid arguments look like this:Īlso, make sure you just use whole numbers when specifying your arguments. When setting the Java heap size, you should specify your memory argument using one of the letters “m” or “M” for MB, or “g” or “G” for GB. Java memory arguments (xms, xmx, xmn) formatting (MB, GB) The maximum heap limit is about 2 GB (2048MB). (The -server flag increases the default size to 128M.) Sets the maximum size to which the Java heap can grow. (The -server flag increases the default size to 2M.) Sets the initial Java heap size for the Eden generation. (The -server flag increases the default size to 32M.) The values must be a multiple of, and greater than, 1024 bytes (1KB). Java heap size descriptions (xms, xmx, xmn)ĭigging around, I just found this additional Java xms, xmx, and xmn information on Apple's web site: -Xms size in bytes

Xnoclassgc disable class garbage collection The -X options are non-standard and subject to change without notice.įrom that list, the command-line arguments specifically related to Java application memory use are: Xdock:name= override default application name displayed in dock -Xdock:icon= override default icon displayed in dock -Xcheck:jni perform additional checks for JNI functions -Xshare:off do not attempt to use shared class data -Xshare:auto use shared class data if possible (default) -Xshare:on require using shared class data, otherwise fail. Xrs reduce use of OS signals by Java/VM (see documentation) Xfuture enable strictest checks, anticipating future default Xbootclasspath: set search path for bootstrap classes and resources -Xbootclasspath/a: append to end of bootstrap class path -Xbootclasspath/p: prepend in front of bootstrap class path -Xnoclassgc disable class garbage collection -Xloggc: log GC status to a file with time stamps Here's what the output of those commands looks like from my JVM: You can find more options for controlling Java application memory use by looking at the output of the java -X command. (The important part here is the -Xm圆4m portion of the command.) More Java memory-related command line arguments Where THE_CLASSPATH and PROGRAM_NAME are variables set earlier in my script. Use this syntax to specify the amount of memory the JVM should use:

Use -Xss to set the Java thread stack size.

Use -Xms to specify the initial Java heap size.

Use -Xmx to specify the maximum heap size.

The short answer is that you use these java command-line parameters to help control the RAM use of application: Java memory FAQ: How do I control the amount of memory my Java program uses (i.e., Java RAM usage)? The short answer

Java memory disk map