gistfile1.rb

irb(main):001:0> require 'java'
          => true
irb(main):002:0> 1.to_java.class 
          => Java::JavaLang::Long
irb(main):003:0> //.to_java.class
          ArgumentError: wrong number of arguments (0 for 2)
            from /opt/jruby/lib/ruby/1.8/irb.rb:310:in `output_value'
            from /opt/jruby/lib/ruby/1.8/irb.rb:159:in `eval_input'
            from /opt/jruby/lib/ruby/1.8/irb.rb:271:in `signal_status'
            from /opt/jruby/lib/ruby/1.8/irb.rb:155:in `eval_input'
            from /opt/jruby/lib/ruby/1.8/irb/ruby-lex.rb:244:in `each_top_level_statement'
            from org/jruby/RubyKernel.java:1417:in `loop'
            from /opt/jruby/lib/ruby/1.8/irb/ruby-lex.rb:230:in `each_top_level_statement'
            from org/jruby/RubyKernel.java:1190:in `catch'
            from /opt/jruby/lib/ruby/1.8/irb/ruby-lex.rb:229:in `each_top_level_statement'
            from /opt/jruby/lib/ruby/1.8/irb.rb:154:in `eval_input'
            from /opt/jruby/lib/ruby/1.8/irb.rb:71:in `start'
            from org/jruby/RubyKernel.java:1190:in `catch'
            from /opt/jruby/lib/ruby/1.8/irb.rb:70:in `start'
            from /usr/bin/jirb:13:in `(root)'
          Maybe IRB bug!!