You can try java script executer like this
JavascriptExecutor jse=(JavascriptExecutor)this.driver; String script = "return document.getElementById('hidden_element_id_here').innerHTML"; jse.executeScript(script);
JavascriptExecutor jse=(JavascriptExecutor)this.driver;
String script = "return document.getElementById('hidden_element_id_here').innerHTML";
jse.executeScript(script);