- Install Native Image
- Build Native Image
- How to Determine What Version of GraalVM a Native Image is Generated with
The Native Image component of GraalVM Enterprise allows to compile a JVM-based application ahead-of-time under closed-world assumption into an executable image or a shared object (ELF-64 or 64-bit Mach-O), called a native image.
The input is Java bytecode, compiled from any JVM language. The entire process
that produces a native image is image build time to clearly distinguish it
from the compilation of Java source code to bytecode. The Native Image
native-image is a Java application that processes all the classes of an
application and its dependencies, dependent JDK libraries and VM components. It
statically analyses that data to determine which classes and methods are
reachable and used during application execution. Then it passes all this
reachable code as the input to the GraalVM compiler which ahead-of-time compiles
it to a native executable for a specific operating system and architecture.
Install Native Image
Native Image is distributed as a separate installable and can be added to GraalVM Enterprise with the GraalVM Updater tool. Download the Native Image component from Oracle Technology Network. You must accept the License Agreement before downloading. Then install Native Image from the JAR file:
- on macOS
gu -L install ./native-image-installable-svm-svmee-<java8/java11>-darwin-amd64-<version>.jar
- on Linux
gu -L install ./native-image-installable-svm-svmee-<java8/java11>-linux-amd64-<version>.jar
- on Windows
gu -L install ./native-image-installable-svm-svmee-<java8/java11>-windows-amd64-<version>.jar
-L, equivalent to
--file, tells to treat a local filename of the packaged component as a parameter.
Optionally, you can install Native Image from a local components collection:
gu install -C /path/to/downloads/directory native-image
When installing components from a given directory, you can allow installing all components which have a correct version number for GraalVM Enterprise using wildcards:
gu install -C ~/Download/Components/ native*
After this additional step, the
native-image executable will become available in
Build Native Image
To build an image for a class in the current working directory, use:
native-image [options] class [imagename] [options]
To build an image for a jar file, use:
native-image [options] -jar jarfile [imagename] [options]
native-image command needs to provide the class path for all classes using
the familiar option from the
-cp followed by a list of
directories or .jar files, separated by
:. The name of the class containing
the main method is the last argument, or you can use
-jar and provide a .jar
file that specifies the main method in its manifest.
native-image supports JVM-based languages, e.g., Java, Scala, Kotlin.
The resulting native image can, optionally, execute dynamic languages
like Ruby, R, or Python, but it does not pre-compile their code itself. Polyglot
embeddings can also be compiled ahead-of-time. To inform
native-image of guest
languages used by an application, specify
--language:<languageId> for each
guest language used (e.g.,
native-image depends on the local toolchain, so please make
zlib-devel (header files for the C library and
gcc are available on your system. For Linux platform, install
dependency additionally. For instance, on Oracle Linux run:
yum install libstdc++-static`
Another prerequisite to consider is the maximum heap size. Physical memory for
running a JVM-based application may be insufficient to build a native image. For
server-based image building, it is allowed to use 80% of the reported physical RAM for
all servers together, but never more than 14GB per server (for exact details
please consult the native-image source code). If you run with
option, you will get the whole 80% of what is reported as physical RAM as the
baseline. This mode respects
-Xmx arguments additionally.
Prerequisites for Using Native Image on Windows
To make use of Native Image on Windows, follow the further recommendations. The required Microsoft Visual C++ (MSVC) version depends on the JDK version that GraalVM is based on. For GraalVM Enterprise distribution based on JDK 8, you will need MSVC 2010 SP1 version. The recommended installation method is using Microsoft Windows SDK 7.1:
- Download the SDK file
GRMSDKX_EN_DVD.isofor from Microsoft.
- Mount the image by opening
For GraalVM Enterprise distribution based on JDK 11, you will need MSVC 2017 15.5.5 or later version.
The last prerequisite, common for both GraalVM distribution based on JDK 11 and JDK 8, is the proper Developer Command Prompt for your version of Visual Studio. Namely, it is should be the x64 Native Tools Command Prompt. Use Visual Studio 2017 or later.
How to Determine What Version of GraalVM a Native Image is Generated with
Assuming you have a Java class file EmptyHello.class containing an empty main method
and have generated an empty shared object
emptyhello with the Native Image builder of it:
$ native-image -cp hello EmptyHello Build on Server(pid: 11228, port: 41223) [emptyhello:11228] classlist: 149.59 ms ...
If you do not know what GraalVM distribution is set to the
To determine if a native image was compiled with GraalVM Community or
GraalVM Enterprise, run this command:
$ strings emptyhello | grep com.oracle.svm.core.VM
The expected output should match the following:
com.oracle.svm.core.VM GraalVM EE
Important: Python source code or LLVM bitcode interpreted or compiled with GraalVM Community will not have the same security characteristics as the same code interpreted or compiled using GraalVM Enterprise. There is a string embedded in each image that allows to figure out the version and variant of the base (Community or Enterprise) used to build an image. The following command will query that information from an image:
strings <path to native-image exe or shared object> | grep com.oracle.svm.core.VM