Get attribute for an element

Using xPath: 

String var = selenium.getAttribute("//input[@name='q']/@maxlength");
        System.out.println(var);

Using csslocator:

String var = selenium.getAttribute("css=input[name='q']@maxlength");
        System.out.println(var);

Using webdriver: 

String var = webDriver.findElement(By.xpath("//input[@name='q']")).getAttribute("maxlength")
        System.out.println(var);