How to find out the total memory in Java ME

The current total heap memory of VM is retrieved using the following code

Runtime runt=Runtime.getRuntime();
long totalMemory = runt.totalMemory();

This method however doesn't return all available possible memory in all Java VM implementations like in S60. S60 uses a VM in allocates it's VM heap memory dynamically from operating system. During startup certain amount of heap is reserved but when the memory will be used and the free amount is becoming smaller VM dynamically allocates more heap from OS. The VM also releases unnecessary heap back to operating system. This kind of implementation is important in operating environment with true multitasking capabilities like S60.

In S60 3rd Edition devices there is a system property

com.nokia.memoryramfree

that can be used to query the available RAM available in the operating system. This is much more reliable estimate of available RAM. Although it should be understood that any other application may use this RAM.

Article Metadata

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Code Example

Source file: Media:MemoryTestMIDletSource.zip

Installation file: Media:MemoryTestMIDletBinaries.zip

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Tested with

SDK: Nokia SDK 1.1 for Java Nokia SDK 2.0 for Java (beta) Nokia Symbian Belle 1.0

Devices(s): C3-01, Asha 305, E7-00

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Compatibility

Platform(s): S40, Symbian Belle

Device(s): All

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Article

Created: jaakl (15 Sep 2009)

Updated: skalogir (04 Nov 2011)

Reviewed: skalogir (20 May 2011)

Last edited: hamishwillee (07 Aug 2012)