[Java] how to embed JRuby

Embed JRuby

if( ((String)langCombo.getSelectedItem()).equalsIgnoreCase("ruby") ) {
    SwingUtilities.invokeLater(() -> {
        try {
            if( rubyScript == null ) {
                rubyScript = new ScriptingContainer();
                rubyWriter = new StringWriter();
                rubyScript.setOutput(rubyWriter);
                rubyScript.runScriptlet("def write(text) print(text) end\n");
                rubyScript.runScriptlet("def writeln(text) print(text + \"\\n\") end\n");
            }
            outputPrintLn("<START Ruby>");
            rubyScript.runScriptlet(textTab.getSelectedTextView().getText());
            outputPrint(rubyWriter.toString());
            rubyWriter.getBuffer().setLength(0);
            rubyWriter.getBuffer().trimToSize();
            outputPrintLn("<END Ruby>");
        } catch (Exception e) {
            e.printStackTrace();
            outputPrintLn("error\n" + e.getMessage());
        } 
    });
}