使用Memcache儲存Session

使用Memcache儲存Session，用來實現負載均衡環境下Session共享的目的

1.使用MemcacheFilter對請求進行攔截

public void doFilter(ServletRequest servletRequest,
			ServletResponse servletResponse, FilterChain filterChain)
			throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) servletRequest;
		HttpServletResponse response = (HttpServletResponse) servletResponse;

		Cookie cookies[] = request.getCookies();
		Cookie sCookie = null;

		String sid = "";
		if (cookies != null && cookies.length > 0) {
			for (int i = 0; i < cookies.length; i++) {
				sCookie = cookies[i];
				if (sCookie.getName().equals(sessionId)) {
					sid = sCookie.getValue();
				}
			}
		}

		if (sid == null || sid.length() == 0) {
			sid = java.util.UUID.randomUUID().toString();
			Cookie mycookies = new Cookie(sessionId, sid);
			mycookies.setMaxAge(-1);
			if (this.cookieDomain != null && this.cookieDomain.length() > 0) {
				mycookies.setDomain(this.cookieDomain);
			}
			mycookies.setPath(this.cookiePath);
			response.addCookie(mycookies);
		}

		filterChain.doFilter(new HttpServletRequestWrapper(sid, request),
				servletResponse);
	}

2.自定義的HttpServletRequestWrapper類

public class HttpServletRequestWrapper extends
		javax.servlet.http.HttpServletRequestWrapper {

	String sid = "";

	public HttpServletRequestWrapper(String sid, HttpServletRequest arg0) {
		super(arg0);
		this.sid = sid;
	}

	public HttpSession getSession(boolean create) {
		return new HttpSessionSidWrapper(this.sid, super.getSession(create));
	}

	public HttpSession getSession() {
		return new HttpSessionSidWrapper(this.sid, super.getSession());
	}

}

3.自定義的HttpSession類

public HttpSessionSidWrapper(String sid, HttpSession session) {
		super(session);
		this.sid = sid;
		this.map = MemcacheSessionService.getInstance().getSession(sid);
<span style="white-space:pre">	</span>}

4.使用Memcache客戶端連接Memcache服務器，並使用其存儲Session對象

public Map<String,Object> getSession(String id) {
		MemCachedClient mc = this.getMemCachedClient();
		Object mp = mc.get(id);
		Map<String,Object> session = null;
		if (mp == null) {
			session = new HashMap<String,Object>();
			mc.set(id, session, new Date(TIME_OUT));//更新session
		}else {
			session =(Map<String,Object>)mp;
			mc.set(id, session, new Date(TIME_OUT));//更新session
		}		
		return session;
	}

如何配置MemcacheClient請自行百度