IKVM is an implementation of Java for the Microsoft .NET platform. It can be used to quickly and easily:
- Execute compiled Java code (bytecode) on .NET Framework or .NET Core
- Convert bytecode to a .NET assembly to directly access its API in a .NET project
These tasks can be done without porting source code to .NET.
- A Java virtual machine (JVM) implemented in .NET
- A .NET implementation of the Java class libraries
- A tool that translates Java bytecode (JAR files) to .NET IL (DLL or EXE files).
- Tools that enable Java and .NET interoperability
- Statically: By compiling a Java application into a .NET assembly using
<MavenReference>,<IkvmReference>orikvmc.- Libary assemblies can be referenced by any .NET application with a compatible target framework and platform. Types can be referenced by using the Java package name like a .NET namespace.
- Executable assemblies can be launched by specifying the class containing the
main()method to execute at runtime when building usingikvmc.
- Dynamically: By running a Java application using the
ikvmtool, which can be used as a direct replacement forjava.exe. The Java bytecode is converted on-the-fly to CIL and executed.
- A converter utility to transform Java source code to C# source code
- A decompiler utitity to transform compiled Java bytecode to C# source code
- A tool that runs .NET code in Java - all IKVM conversions are Java > .NET
- .NET Framework 4.6.1 and higher
- .NET Core 3.1 and higher
- .NET 5 and higher
- Java SE 8
See the tutorial to get started or IKVM.NET In Details for a more in-depth look.
PM> Install-Package IKVMOr, to use MavenReference:
PM> Install-Package IKVM.Maven.SdkThe tools are available for download on the Releases page.
IKVM supports integration with .NET SDK projects as well as low level tools for running compiled Java code directly or for advanced build scenarios. The 2 main entry points for integration with the .NET SDK are IkvmReference and MavenReference. .NET SDK projects can be built on the command line directly or using an IDE that supports them, such as recent versions Visual Studio or JetBrains Rider.
IKVM includes build-time support for translating Java libraries to .NET assemblies. Install the IKVM package in a project that requires references to Java libraries. Use IkvmReference within an ItemGroup to indicate which Java libraries your project requires.
<ItemGroup>
<PackageReference Include="IKVM" Version="8.2.0" />
</ItemGroup>
<ItemGroup>
<IkvmReference Include="..\..\ext\helloworld-2.0.jar" />
</ItemGroup>The output assembly will be generated as part of your project's build process and a reference will automatically be added to your project so you can call APIs of the compiled .jar assembly. Additional metadata can be added to IkvmReference to customize the assembly that is generated.
<ItemGroup>
<IkvmReference Include="..\..\ext\helloworld-2.0.jar">
<AssemblyName>MyAssembly</AssemblyName>
<AssemblyVersion>3.2.1.0</AssemblyVersion>
<AssemblyFileVersion>3.0.0.0</AssemblyFileVersion>
<DisableAutoAssemblyName>true</DisableAutoAssemblyName>
<DisableAutoAssemblyVersion>true</DisableAutoAssemblyVersion>
<FallbackAssemblyName>MyAssemblyFallback</FallbackAssemblyName>
<FallbackAssemblyVersion>3.1.0.0</FallbackAssemblyVersion>
<KeyFile>MyKey.snk</KeyFile>
<DelaySign>true</DelaySign>
<Compile>SomeInternalDependency.jar;SomeOtherInternalDependency.jar</Compile>
<Sources>MyClass.java;YourClass.java</Sources>
<References>SomeExternalDependency.jar;SomeOtherExternalDependency.jar</References>
<Aliases>MyAssemblyAlias;helloworld2_0</Aliases>
<Debug>true</Debug>
</IkvmReference>
</ItemGroup>The following values can be used as either an attribute or a nested element of <IkvmReference>.
| Attribute or Element | Description |
|---|---|
Include (attribute only) |
The identity of the IkvmReference item. The value can be one of:
|
AssemblyName |
By default the AssemblyName is generated using the rules defined by the Automatic-Module-Name specification. To override this, do so here. The value should not include a file extension, .dll will be appended automatically. |
AssemblyVersion |
By default the AssemblyVersion is generated using the rules defined by the Automatic-Module-Name specification. To override this, do so here. |
AssemblyFileVersion |
By default the AssemblyFileVersion is generated using the rules defined by the Automatic-Module-Name specification or, if overridden, the same value as AssemblyVersion. To override this, do so here. |
DisableAutoAssemblyName |
If true disables detection of AssemblyName. |
DisableAutoAssemblyVersion |
If true disables detection of AssemblyVersion. |
FallbackAssemblyName |
If AssemblyName is not provided or cannot be calculated, use this value. |
FallbackAssemblyVersion |
If AssemblyVersion is not provided or cannot be calculated, use this value. |
KeyFile |
Specifies the filename containing the cryptographic key. When this option is used, the compiler inserts the public key from the specified file into the assembly manifest and then signs the final assembly with the private key. |
DelaySign |
This option causes the compiler to reserve space in the output file so that a digital signature can be added later. Use DelaySign if you only want to place the public key in the assembly. The DelaySign option has no effect unless used with KeyFile. |
Compile |
A semi-colon separated list of Java class path items to compile into the assembly. By default this value is the Identity of the item, if the identity of the item is an existing JAR file or directory (not yet supported). MSBuild globs are supported to reference multiple JAR or .class files. |
Sources |
A semi-colon separated list of Java source files to use during documentation generation. (not yet supported) |
References |
Optional semi-colon separated list of other IkvmReference identity values to specify as a reference to the current one. For example, if foo.jar depends on bar.jar, include both as IkvmReference items, but specify the identity of bar.jar on the References metadata of foo.jar. |
Debug |
Optional boolean indicating whether to generate debug symbols. By default this is determined based on the <DebugType> and <DebugSymbols> properties of the project. Only full debug symbols are currently supported. |
Aliases |
A semi-colon separated list of aliases that can be used to reference the assembly in References. |
All other metadata supported on the Reference MSBuild item group definition. |
IkvmReference is not transitive. Including it in one project and adding a dependency to that project from a second
project will not result in the same reference being available on the second project. Instead, add the reference to
each project.
For each project to resolve to the same resulting assembly ensure their settings are identical.
Multiple IkvmReference entries can be configured to include each other as references.
<ItemGroup>
<IkvmReference Include="helloworld.jar">
<AssemblyVersion>1.0.0.0</AssemblyVersion>
</IkvmReference>
<IkvmReference Include="helloworld-2.jar">
<AssemblyName>helloworld-2</AssemblyName>
<AssemblyVersion>2.0.0.0</AssemblyVersion>
<References>helloworld.jar</References>
<Aliases>helloworld2</Aliases>
</IkvmReference>
</ItemGroup>The Automatic-Module-Name is either a specified attribute of the JAR manifest, which can be found in the META-INF/MANIFEST.MF file inside the JAR, or a generated value based on the name of the JAR file. See the documentation for more information.
See the ikvm-maven Readme for usage instructions.