Ruby on Rails Vs Java

Java is very popular programming language in the world but ruby on rails is relatively new and young programming language. To compare two programming languages normally SW Engineers consider about language performance, security, Development speed, Maintainability,Scaling and Development tools
By comparing with Rails and Java, Rails Development speed and Maintainability little bit higher than Java. Reason for that is ruby on rails is less configuration and also it practice agile development, further more lot of plugins are available for ruby on rails development.But consider about scalability rails is in far behind to java. Java supports multi- threading but ruby not that much.Clustering also good in Java but not that much in rails. Ruby on Rails is easy to learn and code is more human readable but Java is hard to learn and not that much human readable.