driver.switchTo().frame(driver.findElement(By.className("APP-editor-iframe")));

WebElement editor = driver.findElement(By.tagName("body"));

JavascriptExecutor jsExecutor = (JavascriptExecutor) driver;

jsExecutor.executeScript("arguments[0].innerHTML = '<h1>Selenium Test </h1>I love Selenium <br> this article Post By Selenium WebDriver<br><h2>Create By Young</h2>'", editor);

driver.switchTo().defaultContent();

 /**

     * @author hjianhui

     * @param locator

     * @param text

     */

    protected void setRichTextBox(Locator locator, String text) {

        WebElement e = findElement(driver, locator);

        log.info("type value is:  " + text);

        JavascriptExecutor js = (JavascriptExecutor) driver;

        js.executeScript("arguments[0].innerHTML = \"" + text + "\"", e);

    }