core-client/src/test/java/org/glassfish/jersey/client/TerminalClientRequestFilter.java

/*
 * Copyright (c) 2014, 2018 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package org.glassfish.jersey.client;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.List;
import java.util.Optional;

import javax.ws.rs.client.ClientRequestContext;
import javax.ws.rs.client.ClientRequestFilter;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response;

/**
 * Client request filter, which doesn't perform actual requests.
 *
 * Sets the response based on various request properties:
 * <ul>
 *     <li>Response code is value of request header {@code "Response-Status"} or {@code 200}, if not present.</li>
 *     <li>Response entity is request entity or {@code "NO-ENTITY"}, if request entity is not present.</li>
 *     <li>Response headers do contain all request headers, names are prefixed by {@code "Test-Header-"}.</li>
 *     <li>Response headers do contain all request properties, names are prefixed by {@code "Test-Property-"}.</li>
 * </ul>
 *
 * Additionally, response headers contain {@code "Test-Thread"} (current thread name), {@code "Test-Uri"} (request Uri)
 * and {@code "Test-Method"} (request Http method).
 *
 * @author Michal Gajdos
 */
class TerminalClientRequestFilter implements ClientRequestFilter {

    @Override
    public void filter(final ClientRequestContext requestContext) throws IOException {
        // Obtain entity - from request or create new.
        final ByteArrayInputStream entity = new ByteArrayInputStream(
                requestContext.hasEntity() ? requestContext.getEntity().toString().getBytes() : "NO-ENTITY".getBytes()
        );

        final int responseStatus = Optional.ofNullable(requestContext.getHeaders().getFirst("Response-Status"))
                                           .map(Integer.class::cast)
                                           .orElse(200);

        Response.ResponseBuilder response = Response.status(responseStatus)
                                                    .entity(entity)
                                                    .type("text/plain")
                                                    // Test properties.
                                                    .header("Test-Thread", Thread.currentThread().getName())
                                                    .header("Test-Uri", requestContext.getUri().toString())
                                                    .header("Test-Method", requestContext.getMethod());

        // Request headers -> Response headers (<header> -> Test-Header-<header>)
        for (final MultivaluedMap.Entry<String, List<String>> entry : requestContext.getStringHeaders().entrySet()) {
            response = response.header("Test-Header-" + entry.getKey(), entry.getValue());
        }

        // Request properties -> Response headers (<header> -> Test-Property-<header>)
        for (final String property : requestContext.getPropertyNames()) {
            response = response.header("Test-Property-" + property, requestContext.getProperty(property));
        }

        requestContext.abortWith(response.build());
    }
}