dexifying 18.5 MB "android-4.1.1_r1.jar" gives " java.lang.OutOfMemoryError: Java heap space"

Question

I am trying to launch OSGI framework and to start few bundles on Android. One of these bundles is android API bundle which is an 18.5 MB jar. I read that in order to start the bundles on android, all the bundles should be first dexified.

So I tried to dexify this "android-4.1.1_r1.jar" using the following commands:

dx --dex --output=classes.dex C:\Users\student\Documents\eclipse\myPlugins\plugins\android-4.1.1_r1.jar 

but I got this error on my command line:

java.lang.OutOfMemoryError: Java heap space

First: Do I really need to dexify this file? Second: if I have to dexify it, then how can I get rid of the above error?

to increase my heap size,

I tried: java -Xmx4g, but I got

Invalid maximum heap size: -Xmx4g
The specified size exceeds the maximum representable size.
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

then I tried java -Xmx2g, but i got

Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

so I tried java -Xmx1g, and java -Xmx1100g then I got:

Usage: java [-options] class [args...]
           (to execute a class)
   or  java [-options] -jar jarfile [args...]
           (to execute a jar file)
where options include:
    -d32          use a 32-bit data model if available
    -d64          use a 64-bit data model if available
    -client       to select the "client" VM
    -server       to select the "server" VM
    -hotspot      is a synonym for the "client" VM  [deprecated]
                  The default VM is client.

    -cp <class search path of directories and zip/jar files>
    -classpath <class search path of directories and zip/jar files>
                  A ; separated list of directories, JAR archives,
                  and ZIP archives to search for class files.
    -D<name>=<value>
                  set a system property
    -verbose[:class|gc|jni]
                  enable verbose output
    -version      print product version and exit
    -version:<value>
                  require the specified version to run
    -showversion  print product version and continue
    -jre-restrict-search | -no-jre-restrict-search
                  include/exclude user private JREs in the version search
    -? -help      print this help message
    -X            print help on non-standard options
    -ea[:<packagename>...|:<classname>]
    -enableassertions[:<packagename>...|:<classname>]
                  enable assertions with specified granularity
    -da[:<packagename>...|:<classname>]
    -disableassertions[:<packagename>...|:<classname>]
                  disable assertions with specified granularity
    -esa | -enablesystemassertions
                  enable system assertions
    -dsa | -disablesystemassertions
                  disable system assertions
    -agentlib:<libname>[=<options>]
                  load native agent library <libname>, e.g. -agentlib:hprof
                  see also, -agentlib:jdwp=help and -agentlib:hprof=help
    -agentpath:<pathname>[=<options>]
                  load native agent library by full pathname
    -javaagent:<jarpath>[=<options>]
                  load Java programming language agent, see java.lang.instrument

    -splash:<imagepath>
                  show splash screen with specified image
See http://www.oracle.com/technetwork/java/javase/documentation/index.html for m
ore details.

In all cases, I still get the same error when I try to dexify the bundle file. What should I do? I am using Windows 32 bits with 4.00 GB installed (2.96 GB usable).

Answer 1

The maximum heap size is determined by a number of things, including:

• Whether you are running a 32 or 64 bit JVM.
• Whether you are running on a 32 or 64 bit OS.
• What OS / version you are using.
• How much physical memory you have.
• Whether your system has enough disc space allocated for paging.
• How much non-heap memory your Java application requires.

On a modern 32bit windows (without PAE) the maximum you are likely to be able to request is likely to be 1.4Gb to 1.6Gb (reference). So -Xmx1g should work ... unless you've got a lot of other things running at the same time.

---

So are you saying that what I showed above worked?

No.

I'm saying that it should have worked. The fact that you got a "usage" message is puzzling. I think it means there is something else wrong with the command line. (Did you forget to tell java what class to run?)

A corollary from what I said is that it might work if you shut down various other applications (like your IDE, your web browser, your email client) to free up memory and/or paging file space. (A reboot might help too ... if your page file has gotten badly fragmented.)

If that doesn't help then:

• You could try splitting the JAR file into smaller JAR files.
• You could doing the dexing on a larger machine.
• You could install Linux ... which will allow you to create a significantly bigger Java heap on the same hardware.