xmake-repo/packages/o/openjdk/fetch.lua

function main(package, opt)
    if not opt.system then
        return
    end

    local java = package:find_tool("java", opt)
    if not java then
        return
    end

    local result = {}
    result.version = java.version

    if package:is_binary() then
        return result
    end

    if is_host("windows") then
        local sdkdir = os.getenv("JAVA_HOME")
        if not os.isdir(sdkdir) then
            return
        end

        result.includedirs = {path.join(sdkdir, "include"), path.join(sdkdir, "include/win32")}
        result.linkdirs = path.join(sdkdir, "lib")
        result.links = {"jvm", "jawt"}
        result.bindirs = {path.join(sdkdir, "bin"), path.join(sdkdir, "bin/server")}
        return result
    end
    -- TODO: linux, mac
    -- ubuntu: /usr/lib/jvm/java-11-openjdk-amd64
end