The source code provided with samples and demos for the JDK is meant to illustrate the usage of a given feature or technique and has been deliberately simplified. Additional steps required for a production-quality application, such as security checks, input validation, and proper error handling, might not be present in the sample code. In some cases, the default security settings may block an execution of demo applets in a browser. To adjust the security settings, please refer to the following resource: http://java.com/en/download/help/java_blocked.xml Some demo applets need to be accessed through the HTTP or HTTPS protocols to enable access to the required resources.