language/java: deprecate java_home_cmd

Library/Homebrew/compat.rb

@@ -3,5 +3,6 @@
 require "compat/extend/nil"
 require "compat/extend/string"
 require "compat/formula"
+require "compat/language/java"
 require "compat/language/python"
 require "compat/os/mac" if OS.mac?

Library/Homebrew/compat/language/java.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module Language
+  module Java
+    class << self
+      module Compat
+        def java_home_cmd(version = nil)
+          odeprecated "Language::Java::java_home_cmd", "Language::Java::java_home"
+
+          # macOS provides /usr/libexec/java_home, but Linux does not.
+          return system_java_home_cmd(version) if OS.mac?
+
+          raise NotImplementedError
+        end
+      end
+
+      prepend Compat
+    end
+  end
+end

Library/Homebrew/extend/os/mac/language/java.rb

@@ -2,19 +2,20 @@
 
 module Language
   module Java
-    def self.java_home_cmd(version = nil)
+    def self.system_java_home_cmd(version = nil)
       version_flag = " --version #{version}" if version
       "/usr/libexec/java_home#{version_flag}"
     end
+    private_class_method :system_java_home_cmd
 
     def self.java_home(version = nil)
-      cmd = Language::Java.java_home_cmd(version)
+      cmd = system_java_home_cmd(version)
       Pathname.new Utils.popen_read(cmd).chomp
     end
 
     # @private
     def self.java_home_shell(version = nil)
-      "$(#{java_home_cmd(version)})"
+      "$(#{system_java_home_cmd(version)})"
     end
   end
 end

Library/Homebrew/language/java.rb

@@ -2,11 +2,6 @@
 
 module Language
   module Java
-    def self.java_home_cmd(_ = nil)
-      # macOS provides /usr/libexec/java_home, but Linux does not.
-      raise NotImplementedError
-    end
-
     def self.java_home(version = nil)
       req = JavaRequirement.new [*version]
       raise UnsatisfiedRequirements, req.message unless req.satisfied?