ContextUtils.java

package com.aggrepoint.winlet;

import java.util.function.Consumer;
import java.util.function.Function;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.method.HandlerMethod;

import com.aggrepoint.winlet.spring.WinletDispatcherServlet;

/**
 * @see ReqInfoImpl
 * 
 * @author Jiangming Yang (yangjm@gmail.com)
 */
public class ContextUtils {
	public static final String REQUEST_ATTR_REQUEST = ContextUtils.class
			.getName() + "REQ_INFO";

	private static String REQUEST_WEB_APP_CONTEXT = ContextUtils.class
			.getName() + ".REQUEST_WEB_APP_CONTEXT";
	private static String REQUEST_USER_ENGINE = ContextUtils.class.getName()
			+ ".REQUEST_USER_ENGINE";
	private static String REQUEST_RULE_ENGINE = ContextUtils.class.getName()
			+ ".REQUEST_RULE_ENGINE";
	private static String REQUEST_AUTHORIZATION_ENGINE = ContextUtils.class
			.getName() + ".REQUEST_AUTH_ENGINE";
	private static String REQUEST_PSN_RULE_ENGINE = ContextUtils.class
			.getName() + ".REQUEST_PSN_RULE_ENGINE";
	private static String REQUEST_CONFIG_PROVIDER = ContextUtils.class
			.getName() + ".REQUEST_CONFIG_PROVIDER";
	private static String REQUEST_LIST_PROVIDER = ContextUtils.class.getName()
			+ ".REQUEST_LIST_PROVIDER";
	private static String REQUEST_HANDLER_METHOD = ContextUtils.class.getName()
			+ ".REQUEST_HANDLER_METHOD";
	private static String REQUEST_LOGINFO_KEY = LogInfoImpl.class.getName()
			+ ".REQUEST_LOGINFO_KEY";
	private static String REQUEST_DISPATCHER = LogInfoImpl.class.getName()
			+ ".REQUEST_DISPATCHER_KEY";

	public static ReqInfoImpl getReqInfo() {
		try {
			return (ReqInfoImpl) RequestContextHolder
					.currentRequestAttributes().getAttribute(
							REQUEST_ATTR_REQUEST,
							RequestAttributes.SCOPE_REQUEST);
		} catch (IllegalStateException e) {
			return null;
		}
	}

	public static void setReqInfo(ReqInfo reqInfo) {
		try {
			RequestContextHolder.currentRequestAttributes().setAttribute(
					REQUEST_ATTR_REQUEST, reqInfo,
					RequestAttributes.SCOPE_REQUEST);
		} catch (IllegalStateException e) {
		}
	}

	static <A, B> B ifNotNull(A obj, Function<A, B> next) {
		if (obj == null)
			return null;
		return next.apply(obj);
	}

	static <A> void ifNotNullNoReturn(A obj, Consumer<A> next) {
		if (obj == null)
			return;
		next.accept(obj);
	}

	public static HttpServletRequest getRequest() {
		return ifNotNull(getReqInfo(), ReqInfoImpl::getRequest);
	}

	public static Object getRequestAttribute(String name) {
		return ifNotNull(getRequest(), (p) -> p.getAttribute(name));
	}

	public static void setRequestAttribute(String name, Object value) {
		ifNotNullNoReturn(getRequest(), (p) -> p.setAttribute(name, value));
	}

	public static void removeRequestAttribute(String name) {
		ifNotNullNoReturn(getRequest(), (p) -> p.removeAttribute(name));
	}

	public static HttpSession getSession() {
		return ifNotNull(getReqInfo(), ReqInfoImpl::getSession);
	}

	public static HttpSession getSession(boolean create) {
		return ifNotNull(getReqInfo(), (p) -> p.getSession(create));
	}

	public static Object getSessionAttribute(String name) {
		return ifNotNull(getSession(), (p) -> p.getAttribute(name));
	}

	public static void setSessionAttribute(String name, Object value) {
		ifNotNullNoReturn(getSession(), (p) -> p.setAttribute(name, value));
	}

	public static void removeSessionAttribute(String name) {
		ifNotNullNoReturn(getSession(), (p) -> p.removeAttribute(name));
	}

	public static LogInfoImpl getLogInfo(HttpServletRequest request) {
		return (LogInfoImpl) request.getAttribute(REQUEST_LOGINFO_KEY);
	}

	public static void setLogInfo(HttpServletRequest request, LogInfo li) {
		if (li == null)
			request.removeAttribute(REQUEST_LOGINFO_KEY);
		request.setAttribute(REQUEST_LOGINFO_KEY, li);
	}

	public static void setApplicationContext(HttpServletRequest request,
			WebApplicationContext context) {
		request.setAttribute(REQUEST_WEB_APP_CONTEXT, context);
	}

	public static WebApplicationContext getApplicationContext(
			HttpServletRequest request) {
		return (WebApplicationContext) request
				.getAttribute(REQUEST_WEB_APP_CONTEXT);
	}

	public static <T> T getBean(HttpServletRequest request, Class<T> clz) {
		return ((WebApplicationContext) request
				.getAttribute(REQUEST_WEB_APP_CONTEXT)).getBean(clz);
	}

	public static <T> T getBean(Class<T> clz) {
		return ((WebApplicationContext) getRequest().getAttribute(
				REQUEST_WEB_APP_CONTEXT)).getBean(clz);
	}

	public static UserEngine getUserEngine(HttpServletRequest request) {
		return (UserEngine) request.getAttribute(REQUEST_USER_ENGINE);
	}

	public static UserProfile getUser(HttpServletRequest request) {
		return ((UserEngine) request.getAttribute(REQUEST_USER_ENGINE))
				.getUser(request);
	}

	public static void setUserEngine(HttpServletRequest request,
			UserEngine userEngine) {
		request.setAttribute(REQUEST_USER_ENGINE, userEngine);
	}

	public static AuthorizationEngine getAuthorizationEngine(
			HttpServletRequest request) {
		return (AuthorizationEngine) request
				.getAttribute(REQUEST_AUTHORIZATION_ENGINE);
	}

	public static void setAuthorizationEngine(HttpServletRequest request,
			AuthorizationEngine engine) {
		request.setAttribute(REQUEST_AUTHORIZATION_ENGINE, engine);
	}

	public static AccessRuleEngine getAccessRuleEngine(
			HttpServletRequest request) {
		return (AccessRuleEngine) request.getAttribute(REQUEST_RULE_ENGINE);
	}

	public static void setAccessRuleEngine(HttpServletRequest request,
			AccessRuleEngine ruleEngine) {
		request.setAttribute(REQUEST_RULE_ENGINE, ruleEngine);
	}

	public static PsnRuleEngine getPsnRuleEngine(HttpServletRequest request) {
		return (PsnRuleEngine) request.getAttribute(REQUEST_PSN_RULE_ENGINE);
	}

	public static void setPsnRuleEngine(HttpServletRequest request,
			PsnRuleEngine ruleEngine) {
		request.setAttribute(REQUEST_PSN_RULE_ENGINE, ruleEngine);
	}

	public static ConfigProvider getConfigProvider(HttpServletRequest request) {
		return (ConfigProvider) request.getAttribute(REQUEST_CONFIG_PROVIDER);
	}

	public static ConfigProvider getConfigProvider() {
		return (ConfigProvider) getRequest().getAttribute(
				REQUEST_CONFIG_PROVIDER);
	}

	public static void setConfigProvider(HttpServletRequest request,
			ConfigProvider provider) {
		request.setAttribute(REQUEST_CONFIG_PROVIDER, provider);
	}

	public static ListProvider getListProvider(HttpServletRequest request) {
		return (ListProvider) request.getAttribute(REQUEST_LIST_PROVIDER);
	}

	public static void setListProvider(HttpServletRequest request,
			ListProvider provider) {
		request.setAttribute(REQUEST_LIST_PROVIDER, provider);
	}

	public static HandlerMethod getHandlerMethod(HttpServletRequest request) {
		return (HandlerMethod) request.getAttribute(REQUEST_HANDLER_METHOD);
	}

	public static void setHandlerMethod(HttpServletRequest request,
			HandlerMethod hm) {
		request.setAttribute(REQUEST_HANDLER_METHOD, hm);
	}

	public static WinletDispatcherServlet getDispatcher(
			HttpServletRequest request) {
		return (WinletDispatcherServlet) request
				.getAttribute(REQUEST_DISPATCHER);
	}

	public static void setDispatcher(HttpServletRequest request,
			WinletDispatcherServlet dispatcher) {
		request.setAttribute(REQUEST_DISPATCHER, dispatcher);
	}
}