package org.jrest4guice.rest;
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.jrest4guice.cache.CacheProvider;
import org.jrest4guice.cache.CacheProviderProvider;
import org.jrest4guice.cache.CacheProviderRegister;
import org.jrest4guice.client.ModelMap;
import org.jrest4guice.commons.http.CookieUtil;
import org.jrest4guice.guice.GuiceContext;
import org.jrest4guice.rest.commons.sna.SNAIdRequestServlet;
import org.jrest4guice.rest.commons.sna.SNASession;
import org.jrest4guice.rest.commons.sna.SNASessionHelper;
import org.jrest4guice.rest.commons.sna.SNASessionProvider;
import org.jrest4guice.rest.exception.ServiceNotFoundException;
import org.jrest4guice.security.SecurityContext;
/**
*
* @author <a href="mailto:zhangyouqun@gmail.com">cnoss (QQ:86895156)</a>
*
*/
public class JRest4GuiceFilterWithSnaSupport extends AbstractJRest4GuiceFilter {
/**
* 缓存服务器的提供者
*/
public static final String CACHE_PROVIDER = "cacheProvider";
/**
* 缓存服务器列表的参数关键字
*/
public static final String CACHE_SERVERS = "cacheServers";
/**
* 缺省的缓存服务提供者
*/
private static final String cacheProviderName = "memcached";
/**
* 缓存提供者
*/
private CacheProvider cacheProvider;
/**
* SNA会话过滤器的助手
*/
private SNASessionHelper helper;
@Override
protected void executeInit(FilterConfig config) throws ServletException {
// 初始化缓存提供者
this.initCacheProvider(config);
}
@Override
protected void executeFilter(HttpServletRequest hRequest,
HttpServletResponse hResponse, FilterChain filterChain, String uri)
throws IOException, ServletException {
Throwable error = null;
HttpSession session = hRequest.getSession();
// REST资源的参数
ModelMap<String, String> params = new ModelMap<String, String>();
// 从当前会话中获取snaId
String snaId = (String) session
.getAttribute(SNAIdRequestServlet.SNA_ID);
// 从缓存服务器获取当前的会话对象
SNASession snaSession = this.helper.getSNASession(snaId, session);
session.setAttribute(CookieUtil.SESSION_NAME, snaId);
try {
HttpServletRequest requestWrapper = this.helper
.createRequestWrapper(hRequest);
// 设置上下文中的环境变量
RestContextManager.setContext(requestWrapper, hResponse, params);
SNASessionProvider.setCurrentSNASession(snaSession);
// 检测用户当前的安全状态
if (requestWrapper.getUserPrincipal() != null) {
SecurityContext securityContext = GuiceContext.getInstance()
.getBean(SecurityContext.class);
GuiceContext.getInstance().injectorMembers(securityContext);
securityContext.getUserPrincipal();
}
// 处理当前请求
new JRest4GuiceProcessor().setUrlPrefix(this.urlPrefix).process(
requestWrapper, hResponse);
} catch (Throwable e) {
error = e;
} finally {
// 从缓存服务器客户删除已空的会话对象
if (snaSession.isEmpty() && snaSession.isDuty()) {
this.cacheProvider.delete(snaId);
} else if (snaSession.isDuty()) {
// 将变更后的会话对象缓存回缓存服务器
snaSession.setDuty(false);
this.cacheProvider.put(snaId, snaSession);
}
// 清除上下文中的环境变量
RestContextManager.clearContext();
SNASessionProvider.clearCurrentSNASession();
}
if(error != null){
if(error instanceof ServiceNotFoundException){
filterChain.doFilter(hRequest, hResponse);
}else
throw new ServletException("JRest4GuiceFilterWithSnaSupport 拦截异常",error);
}
}
/**
* 初始化缓存提供者
*
* @param config
* @throws ServletException
*/
private void initCacheProvider(FilterConfig config) throws ServletException {
String cacheServers = config.getInitParameter(CACHE_SERVERS);
if (cacheServers != null && !cacheServers.trim().equals("")) {
String _cacheProvider = config.getInitParameter(CACHE_PROVIDER);
if (_cacheProvider == null || _cacheProvider.trim().equals(""))
_cacheProvider = cacheProviderName;
// 获取缓存管理的实现
this.cacheProvider = CacheProviderRegister.getInstance()
.getCacheProvider(_cacheProvider);
CacheProviderProvider.setCurrentCacheProvider(this.cacheProvider);
if (this.cacheProvider == null) {
throw new ServletException(
"无法根据名称\""
+ _cacheProvider
+ "\"来初始化缓存提供者，请确认您有没有通过GuiceContext.useCache()来打开Cache的支持！");
}
this.cacheProvider.setCacheServers(cacheServers);
// this.cacheProvider.setExpiryTime(this.sessionTimeOut*1000);
// 初始化SNA会话助手
this.helper = new SNASessionHelper(this.cacheProvider);
}
}
}