This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
There will no be error in the server. But you will not get the desired result when it displayed in the client (browser) (It will display characters in the browser). It because the browser will always assume you want to display text/html.