public class CurrentConnectionInfo implements Filter {

	private static final ThreadLocal<HttpServletRequest> currentRequest = new ThreadLocal<HttpServletRequest>();
	private static final ThreadLocal<HttpServletResponse> currentResponse = new ThreadLocal<HttpServletResponse>();

	public static HttpServletRequest getCurrentRequest() {
		if (currentRequest.get() == null) {
			throw new RuntimeException("not in connection handle cycle");
		}
		return currentRequest.get();
	}

	public static HttpServletResponse getCurrentResponse() {
		if (currentResponse.get() == null) {
			throw new RuntimeException("not in connection handle cycle");
		}
		return currentResponse.get();
	}

	public static HttpSession getSession() {
		return getCurrentRequest().getSession();
	}

	public static boolean hasConnection() {
		return currentRequest.get() != null;
	}

	@Override
	public void doFilter(ServletRequest rq, ServletResponse rs, FilterChain next)
			throws IOException, ServletException {
		try {
			if (rq instanceof HttpServletRequest)
				currentRequest.set((HttpServletRequest) rq);
			if (rs instanceof HttpServletResponse)
				currentResponse.set((HttpServletResponse) rs);
			next.doFilter(rq, rs);
		} finally {
			currentResponse.set(null);
			currentRequest.set(null);
		}
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {

	}

	@Override
	public void destroy() {

	}

}


    <filter>
		<filter-name>currentConnectionFilter</filter-name>
		<filter-class>foo.bar.CurrentConnectionInfo</filter-class>
	</filter>

	<filter-mapping>
		<filter-name>currentConnectionFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>