ServletRequest. getAttribute()

public interface ServletRequest {

    /**
     * Returns the value of the named attribute as an <code>Object</code>, or
     * <code>null</code> if no attribute of the given name exists.
     * <p>
     * Attributes can be set two ways. The servlet container may set attributes
     * to make available custom information about a request. For example, for
     * requests made using HTTPS, the attribute
     * <code>javax.servlet.request.X509Certificate</code> can be used to
     * retrieve information on the certificate of the client. Attributes can
     * also be set programmatically using {@link ServletRequest#setAttribute}.
     * This allows information to be embedded into a request before a
     * {@link RequestDispatcher} call.
     * <p>
     * Attribute names should follow the same conventions as package names.
     * Names beginning with <code>java.*</code> and <code>javax.*</code> are
     * reserved for use by the Servlet specification. Names beginning with
     * <code>sun.*</code>, <code>com.sun.*</code>, <code>oracle.*</code> and
     * <code>com.oracle.*</code>) are reserved for use by Oracle Corporation.
     *
     * @param name
     *            a <code>String</code> specifying the name of the attribute
     * @return an <code>Object</code> containing the value of the attribute, or
     *         <code>null</code> if the attribute does not exist
     */
    public Object getAttribute(String name);