/*
* #%L
* Wisdom-Framework
* %%
* Copyright (C) 2013 - 2014 Wisdom Framework
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
package org.wisdom.api.interception;
import org.wisdom.api.http.Context;
import org.wisdom.api.http.Request;
import org.wisdom.api.http.Result;
import org.wisdom.api.http.Results;
import org.wisdom.api.router.Route;
import java.lang.reflect.InvocationTargetException;
import java.util.*;
import java.util.regex.Pattern;
/**
* The request context let access interceptor to the current HTTP context, filters and interceptors.
* This class is responsible of the request resolution, and so hold the filter chain.
*/
public class RequestContext {
/**
* The invoked route.
*/
private final Route route;
/**
* The filter chain.
*/
private final List<Filter> chain;
/**
* The map storing the configuration for interceptors.
*/
private final Map<Interceptor<?>, Object> interceptors;
/**
* The action parameters.
*/
private Object[] parameters;
/**
* The iterator to retrieve the ordered set of filters.
*/
private ListIterator<Filter> iterator;
/**
* Creates a new Interception Context. Instances should only be created by the router.
*
* @param route the intercepted route
* @param chain the ordered interception chain containing filters and interceptors.
* @param interceptors the set of interceptors and their configuration
* @param parameters the parameters (can be {@code null} if not computed yet)
*/
public RequestContext(Route route, List<Filter> chain, Map<Interceptor<?>, Object> interceptors,
Object[] parameters, Filter endOfChainInvoker) {
this.route = route;
this.interceptors = interceptors;
this.chain = new LinkedList<>(chain);
if (parameters != null) {
this.parameters = Arrays.copyOf(parameters, parameters.length);
}
// Add the action invocation
if (endOfChainInvoker == null) {
endOfChainInvoker = new ActionInvoker();
}
this.chain.add(endOfChainInvoker);
}
/**
* Sets or Updates the parameters of the action method. This method must not be called by filters or interceptors.
* This method is called once the parameter values are computed, this can happen after the creation of the {@link
* org.wisdom.api.interception.RequestContext} instance. This method should only be called by the router instance.
* @param parameters the parameters
* @return the current {@link org.wisdom.api.interception.RequestContext}
*/
public RequestContext setParameters(Object[] parameters) {
this.parameters = parameters;
return this;
}
/**
* Retrieves the configuration annotation for the given interceptor.
*
* @param interceptor the interceptor
* @return the configuration, {@code null} if not found
*/
<A> A getConfigurationForInterceptor(Interceptor<A> interceptor) {
return (A) interceptors.get(interceptor);
}
/**
* Calls the next interceptors.
*
* @return the result from the next interceptor
* @throws java.lang.Exception if the invocation fails.
*/
public Result proceed() throws Exception {
if (iterator == null) {
iterator = chain.listIterator();
}
if (!iterator.hasNext()) {
throw new IllegalStateException("Reached the end of the chain without result.");
}
Filter filter = iterator.next();
return filter.call(route, this);
}
/**
* @return the HTTP context.
*/
public Context context() {
return Context.CONTEXT.get();
}
/**
* @return the incoming request.
*/
public Request request() {
return context().request();
}
/**
* @return the invoked route.
*/
public Route route() {
return route;
}
/**
* Access to the data stored in the request's scope.
* It lets filters and interceptors sharing data. All modifications will be seen by the other participants of the
* chain, action methods and templates.
*
* @return the data
*/
public Map<String, Object> data() {
return request().data();
}
/**
* The end (actually middle) of the chain. This interceptor is a fake calling the action method.
* It does not call {@link RequestContext#proceed()}.
*/
private class ActionInvoker implements Filter {
/**
* We are the end of the chain, so we call the action method.
* If the route is unbound, there are no action method, a {@literal 404 - NOT FOUND} result is returned.
*
* @param route the intercepted route
* @param context the filter context
* @return the result of the action method, {@literal 404 - NOT FOUND} for unbound routes.
* @throws java.lang.reflect.InvocationTargetException if the action method throws an exception
* @throws java.lang.IllegalAccessException if the action method cannot be called
*/
@Override
public Result call(Route route, RequestContext context) throws InvocationTargetException, IllegalAccessException {
if (RequestContext.this.route.isUnbound()) {
return Results.notFound();
} else {
return (Result) RequestContext.this.route.getControllerMethod().invoke(
RequestContext.this.route.getControllerObject(), parameters);
}
}
/**
* @return {@literal null} as it's meaningless here.
*/
@Override
public Pattern uri() {
// Not meaningful here.
return null;
}
/**
* @return {@literal -1} as it's meaningless here.
*/
@Override
public int priority() {
// Anyway, we're the last.
return -1;
}
}
}