CheckRequestProc.java

package kr.co.inger.hotwind.request_check.impl;

import java.io.Serializable;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import kr.co.inger.hotwind.guice.Guicer;
import kr.co.inger.hotwind.request_check.CheckRequest;
import kr.co.inger.hotwind.request_check.RequestProvider;
import kr.co.inger.hotwind.request_check.backend.RequestCheckKvStore;
import kr.co.inger.hotwind.request_check.session.AccessTokenedSession;
import kr.co.inger.hotwind.request_check.session.AccessTokenedSessionProvider;

import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.lang.ObjectUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Strings;

public class CheckRequestProc {

	private static Logger logger = LoggerFactory
			.getLogger(CheckRequestProc.class);

	public Object invoke(MethodInvocation invocation, CheckRequest annot)
			throws Throwable {
		// 일단 저장소를 얻고.
		RequestCheckKvStore store = getRequestCheckKvStore();
		// 캐쉬에서 해당 메서드에 전달하는 맵이나 값이나 인자의 이름 중에 label와 일치하는 값이 캐쉬에 있는지?
		boolean found = false;
		BoxRef<String> storeKeyRef = new BoxRef<String>();
		//
		if (checkHttpHeader(invocation, annot, store, storeKeyRef)) {
			found = true;
		} else if (checkHttpRequestParam(invocation, annot, store, storeKeyRef)) {
			found = true;
		} else if (!Strings.isNullOrEmpty(annot.targetField())) {
			// path-param와 같이 인자로 그대로 전달되는 경우를 위해서.
			for (Object arg : invocation.getArguments()) {
				if (checkAsKeyItself(store, arg)) {
					found = true;
					storeKeyRef.setRef(ObjectUtils.toString(arg));
					break;
				}
			}
		}
		//
		if (found) {
			Map<String, Serializable> session = bindSession(invocation, store,
					storeKeyRef);
			//
			Object result = invocation.proceed();
			// preserve.
			updateStoredSession(store, storeKeyRef, session);
			//
			return result;
		} else {
			throw new Exception(annot.errorMessage());
		}

	}

	private void updateStoredSession(RequestCheckKvStore store,
			BoxRef<String> storeKeyRef, Map<String, Serializable> session) {
		if (session != null && store != null && storeKeyRef != null
				&& storeKeyRef.getRef() != null) {
			//
			final String key = storeKeyRef.getRef();
			if (store.isExists(key)) {
				store.update(key, session);
			} else {
				logger.debug(String.format(
						"update-stored-session skip, not found. -- %s", key));
			}
		}
	}

	private RequestCheckKvStore requestCheckKvStore = null;

	private RequestCheckKvStore getRequestCheckKvStore() throws Exception {
		if (requestCheckKvStore == null) {
			try {
				requestCheckKvStore = Guicer.get().getInstance(
						RequestCheckKvStore.class);
			} catch (Exception exc) {
				logger.error("No binding for RequestCheckKvStore interface!!!");
				throw exc;
			}
		}
		//
		return requestCheckKvStore;
	}

	private Map<String, Serializable> bindSession(MethodInvocation invocation,
			RequestCheckKvStore store, BoxRef<String> storeKeyRef) {
		if (invocation.getThis() instanceof RequestProvider
				&& storeKeyRef.getRef() != null) {
			//
			final String accesstoken = storeKeyRef.getRef();
			//
			Map<String, Serializable> session = (Map<String, Serializable>) store
					.fetch(accesstoken);
			//
			RequestProvider rp = (RequestProvider) invocation.getThis();
			HttpServletRequest req = rp.getHttpServletRequest();
			if (null != req
					.getAttribute(AccessTokenedSessionProvider.SESSION_SAVE_KEY)) {
				AccessTokenedSession ats = (AccessTokenedSession) req
						.getAttribute(AccessTokenedSessionProvider.SESSION_SAVE_KEY);
				ats.setAccesstoken(accesstoken);
				ats.setInnerMap(session);
			} else {
				AccessTokenedSession ats = new AccessTokenedSession();
				ats.setAccesstoken(accesstoken);
				ats.setInnerMap(session);
				req.setAttribute(AccessTokenedSessionProvider.SESSION_SAVE_KEY,
						ats);
			}
			return session;
		} else {
			logger.warn("SKIP set AccessTokenedSession, your JAX-RS resource class isn't a RequestProvider or session-key not-found.");
			return null;
		}
	}

	private boolean checkAsKeyItself(RequestCheckKvStore store, Object arg) {
		if (store.isExists(ObjectUtils.toString(arg))) {
			logger.debug(String.format(
					"arg itself is in request-check-kv-store. (%s)", arg));
			return true;
		} else
			return false;
	}

	private boolean checkHttpHeader(MethodInvocation invocation,
			final CheckRequest annot, RequestCheckKvStore store,
			BoxRef<String> storeKeyRef) {
		try {
			Object obj = invocation.getThis();
			if (obj instanceof RequestProvider
					&& !Strings.isNullOrEmpty(annot.httpHeaderName())) {
				RequestProvider rp = (RequestProvider) obj;
				HttpServletRequest r = rp.getHttpServletRequest();
				final String k = annot.httpHeaderName();
				final String val = (String) r.getHeader(k);
				if (checkAsKeyItself(store, val)) {
					logger.debug(String.format(
							"http-header has %s = %s, and request-checked ok.",
							annot.httpHeaderName(), val));
					storeKeyRef.setRef(val);
					return true;
				}
			}
		} catch (Exception exc) {
			logger.warn(
					"http-header lookup FAIL! please implement RequestProvider in your JAX-RS resource class.",
					exc);
		}
		return false;
	}

	private boolean checkHttpRequestParam(MethodInvocation invocation,
			final CheckRequest annot, RequestCheckKvStore store,
			BoxRef<String> storeKeyRef) {
		try {
			Object obj = invocation.getThis();
			if (!Strings.isNullOrEmpty(annot.targetField())
					&& obj instanceof RequestProvider) {
				RequestProvider rp = (RequestProvider) obj;
				HttpServletRequest r = rp.getHttpServletRequest();
				final String v = r.getParameter(annot.targetField());
				if (checkAsKeyItself(store, v)) {
					logger.debug(String
							.format("http-request has %s = %s, and request-checked ok.",
									annot.targetField(), v));
					storeKeyRef.setRef(v);
					return true;
				}
			}
		} catch (Exception exc) {
			logger.warn(
					"http-parameter lookup FAIL! please implement RequestProvider in your JAX-RS resource class.",
					exc);
		}
		//
		return false;
	}

}