(MODULES-4069) Fail when required params are not available in params.

When overriding all values required for the java setup, there is
no need to fail if params.pp does not support the package.

spec/classes/java_spec.rb

@@ -245,6 +245,34 @@ describe 'java', :type => :class do
     it { is_expected.to contain_package('java').with_name('jre') }
   end
 
+  describe 'custom java package' do
+    let(:facts) { {:osfamily => 'Debian', :operatingsystem => 'Debian', :lsbdistcodename => 'jessie', :operatingsystemrelease => '8.6', :architecture => 'amd64',} }
+    context 'all params provided' do
+      let(:params) { {
+        'distribution'          => 'custom',
+        'package'               => 'custom_jdk',
+        'java_alternative'      => 'java-custom_jdk',
+        'java_alternative_path' => '/opt/custom_jdk/bin/java',
+        'java_home'             => '/opt/custom_jdk',
+      } }
+
+      it { is_expected.to contain_package('java').with_name('custom_jdk') }
+      it { is_expected.to contain_file_line('java-home-environment').with_line('JAVA_HOME=/opt/custom_jdk') }
+      it { is_expected.to contain_exec('update-java-alternatives').with_command('update-java-alternatives --set java-custom_jdk --jre') }
+
+    end
+    context 'missing parameters' do
+      let(:params) { {
+        'distribution' => 'custom',
+        'package' => 'custom_jdk',
+      } }
+      it do
+        expect { catalogue }.to raise_error Puppet::Error, /is not supported. Missing default values/
+      end
+    end
+  end
+
+
   describe 'incompatible OSs' do
     [
       {