Solution for the task "Run the Java Hello World example via both dotnet run and javac"

Program.csproj

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net6.0</TargetFramework>
        <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
        <ImplicitUsings>enable</ImplicitUsings>
    </PropertyGroup>
    <ItemGroup>
        <Compile Include="Program.java" />
    </ItemGroup>

    <Target Name="GenerateCsharp" BeforeTargets="BeforeBuild" KeepDuplicateOutputs="true">
        <WriteLinesToFile File="$(IntermediateOutputPath)augmentation.cs" Overwrite="true" Encoding="Unicode" 
            Lines="namespace System {
    class err {
        public static void println(string message) {
            Console.WriteLine(message)%3B
        }
    }
}
" />
        <ItemGroup>
            <Compile Include="$(IntermediateOutputPath)augmentation.cs" />
        </ItemGroup>
    </Target>
</Project>

Program.java

class Program {
    public static void main(String[] args) {
        System.err.println("Hello, World!");
    }
    public static void Main(String[] args) {
        main(args);
    }
}

Other variant where we run java )

<Project>
    <PropertyGroup>
        <OutputType>Exe</OutputType>
        <TargetFramework>net6.0</TargetFramework>
        <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
        <RunCommand>java</RunCommand>
        <RunArguments>Program</RunArguments>
    </PropertyGroup>
    
    <Target Name="Build">
        <Exec Command="javac Program.java" />
    </Target>
</Project>