do not use unportable readlink utility to find the java_default_home,

use Ruby in a more portable fashion.

adapt tests as well

spec/classes/java_spec.rb

@@ -236,7 +236,7 @@ describe 'java', :type => :class do
   context 'select jdk for OpenBSD' do
     let(:facts) { {:osfamily => 'OpenBSD', :architecture => 'x86_64'} }
     it { is_expected.to contain_package('java').with_name('jdk') }
-    it { is_expected.to contain_file_line('java-home-environment').with_line('JAVA_HOME=/usr/local/jdk/') }
+    it { is_expected.to_not contain_file_line('java-home-environment') }
   end
 
   context 'select jre for OpenBSD' do

spec/unit/facter/java_default_home_spec.rb

@@ -1,47 +1,43 @@
 require "spec_helper"
 
 describe Facter::Util::Fact do
-  before {
-    Facter.clear
-    Facter.fact(:kernel).stubs(:value).returns('Linux')
-  }
 
   describe "java_default_home" do
-    context 'returns java home path when readlink present' do
-      context 'when java is in HOME/jre/bin/java' do
+    before(:each) {
+      Facter.clear
+      Facter.fact(:kernel).stubs(:value).returns('Linux')
+    }
+
+    context 'returns java home path when java found in PATH' do
+      context "when java is in /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java" do
+
         it do
-          java_path_output = <<-EOS
-/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java
-          EOS
-          Facter::Util::Resolution.expects(:which).with("readlink").returns(true)
-          Facter::Util::Resolution.expects(:exec).with("readlink -e /usr/bin/java").returns(java_path_output)
-          expect(Facter.value(:java_default_home)).to eql "/usr/lib/jvm/java-7-openjdk-amd64"
+          File.delete('./java') if File.exist?('./java')
+          File.symlink('/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java', './java')
+          Facter::Util::Resolution.expects(:which).with("java").returns("./java")
+          expect(File.readlink('./java')).to eq('/usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java')
+          expect(Facter.value(:java_default_home)).to eql '/usr/lib/jvm/java-7-openjdk-amd64'
+          File.delete('./java') if File.exist?('./java')
         end
       end
-      context 'when java is in HOME/bin/java' do
+
+      context "when java is in /usr/lib/jvm/oracle-java8-jre-amd64/bin/java" do
+
         it do
-          java_path_output = <<-EOS
-/usr/lib/jvm/oracle-java8-jre-amd64/bin/java
-          EOS
-          Facter::Util::Resolution.expects(:which).with("readlink").returns(true)
-          Facter::Util::Resolution.expects(:exec).with("readlink -e /usr/bin/java").returns(java_path_output)
-          expect(Facter.value(:java_default_home)).to eql "/usr/lib/jvm/oracle-java8-jre-amd64"
+          File.delete('./java') if File.exist?('./java')
+          File.symlink('/usr/lib/jvm/oracle-java8-jre-amd64/bin/java', './java')
+          Facter::Util::Resolution.expects(:which).with("java").returns("./java")
+          expect(File.readlink('./java')).to eq('/usr/lib/jvm/oracle-java8-jre-amd64/bin/java')
+          expect(Facter.value(:java_default_home)).to eql '/usr/lib/jvm/oracle-java8-jre-amd64'
+          File.delete('./java') if File.exist?('./java')
         end
       end
     end
-    context 'returns nil when readlink is present but java is not' do
-      it do
-        java_path_output = ""
-        Facter::Util::Resolution.expects(:which).with("readlink").returns(true)
-        Facter::Util::Resolution.expects(:exec).with("readlink -e /usr/bin/java").returns(java_path_output)
-        expect(Facter.value(:java_default_home)).to be_nil
-      end
-    end
 
-    context 'returns nil when readlink not present' do
+    context 'returns nil when java not present' do
       it do
         Facter::Util::Resolution.stubs(:exec)
-        Facter::Util::Resolution.expects(:which).with("readlink").at_least(1).returns(false)
+        Facter::Util::Resolution.expects(:which).with("java").at_least(1).returns(false)
         expect(Facter.value(:java_default_home)).to be_nil
       end
     end

spec/unit/facter/java_version_spec.rb

@@ -7,7 +7,7 @@ describe Facter::Util::Fact do
 
   describe "java_version" do
     context 'returns java version when java present' do
-      context 'on OpenBSD', :with_env => true do
+      context 'on OpenBSD' do
         before do
           Facter.fact(:operatingsystem).stubs(:value).returns("OpenBSD")
         end
@@ -61,7 +61,7 @@ Java HotSpot(TM) 64-Bit Server VM (build 24.71-b01, mixed mode)
     end
 
     context 'returns nil when java not present' do
-      context 'on OpenBSD', :with_env => true do
+      context 'on OpenBSD' do
         before do
           Facter.fact(:operatingsystem).stubs(:value).returns("OpenBSD")
         end