Merge pull request #16385 from vitorgalvao/java-caveat

Java caveat

doc/CASK_LANGUAGE_REFERENCE.md

@@ -219,6 +219,7 @@ The following methods may be called to generate standard warning messages:
 | --------------------------------- | ----------- |
 | `path_environment_variable(path)` | users should make sure `path` is in their `$PATH` environment variable
 | `zsh_path_helper(path)`           | zsh users must take additional steps to make sure `path` is in their `$PATH` environment variable
+| `depends_on_java(version)`        | users should make sure they have the specified version of java installed (`version` should be one of `6`, `7`, or empty for `8`)
 | `logout`                          | users should log out and log back in to complete installation
 | `reboot`                          | users should reboot to complete installation
 | `files_in_usr_local`              | the Cask installs files to `/usr/local`, which may confuse Homebrew

lib/hbc/caveats.rb

@@ -77,6 +77,24 @@ class Hbc::CaveatsDSL
     end
   end
 
+  def depends_on_java(java_version = 'latest')
+    if java_version == 'latest'
+      puts <<-EOS.undent
+      #{@cask} requires Java. You can install the latest version with
+
+        brew cask install java
+
+      EOS
+    else
+      puts <<-EOS.undent
+      #{@cask} requires Java #{java_version}. You can install it with
+
+        brew cask install caskroom/versions/java#{java_version}
+
+      EOS
+    end
+  end
+
   def logout
     puts <<-EOS.undent
     You must log out and log back in for the installation of #{@cask}