kawa: depend on openjdk

Formula/kawa.rb

@@ -4,17 +4,18 @@ class Kawa < Formula
   url "https://ftp.gnu.org/gnu/kawa/kawa-3.1.1.zip"
   mirror "https://ftpmirror.gnu.org/kawa/kawa-3.1.1.zip"
   sha256 "dab1f41da968191fc68be856f133e3d02ce65d2dbd577a27e0490f18ca00fa22"
+  revision 1
 
   bottle :unneeded
 
-  depends_on :java => "1.7+"
+  depends_on "openjdk"
 
   def install
     rm Dir["bin/*.bat"]
     inreplace "bin/kawa", "thisfile=`command -v $0`",
                           "thisfile=#{libexec}/bin/kawa"
     libexec.install "bin", "lib"
-    bin.install_symlink libexec/"bin/kawa"
+    (bin/"kawa").write_env_script libexec/"bin/kawa", :JAVA_HOME => Formula["openjdk"].opt_prefix
     doc.install Dir["doc/*"]
   end