ValidatorEndpointClearCachedSchemaTest.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package org.apache.camel.component.validator;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.apache.camel.CamelContext;
import org.apache.camel.ContextTestSupport;
import org.apache.camel.Endpoint;
import org.apache.camel.Exchange;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.mock.MockEndpoint;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.impl.DefaultClassResolver;
import org.apache.camel.impl.SimpleRegistry;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Tests whether the ValidatorEndpoint.clearCachedSchema() can be executed when
 * several sender threads are running.
 */
public class ValidatorEndpointClearCachedSchemaTest extends ContextTestSupport {

    private static final Logger LOG = LoggerFactory.getLogger(ValidatorEndpointClearCachedSchemaTest.class);

    private SimpleRegistry simpleReg;

    private CamelContext context;

    @Test
    public void testClearCachedSchema() throws Exception {

        MockEndpoint mock = getMockEndpoint("mock:result");

        // send one message for start up to finish.
        new Sender().run();

        // send with 5 sender threads in parallel and call clear cache in
        // between
        ExecutorService senderPool = Executors.newFixedThreadPool(5);
        ExecutorService executorClearCache = Executors.newFixedThreadPool(1);
        for (int i = 0; i < 5; i++) {
            senderPool.execute(new Sender());
            if (i == 2) {
                /**
                 * The clear cache thread calls xsdEndpoint.clearCachedSchema
                 */
                executorClearCache.execute(new ClearCache());
            }
        }

        senderPool.shutdown();
        executorClearCache.shutdown();

        senderPool.awaitTermination(2, TimeUnit.SECONDS);

        List<Exchange> exchanges = mock.getExchanges();

        assertNotNull(exchanges);

        // expect at least 5 correct sent messages, the messages sent before
        // the clearCacheSchema method is called will fail with a validation
        // error and will nor result in an exchange
        assertTrue("Less then expected exchanges", exchanges.size() > 5);

    }

    @Override
    protected CamelContext createCamelContext() throws Exception {
        simpleReg = new SimpleRegistry();
        context = new DefaultCamelContext(simpleReg);
        context.setClassResolver(new ClassResolverImpl());
        return context;
    }

    @Override
    protected RouteBuilder createRouteBuilder() throws Exception {
        return new RouteBuilder() {
            @Override
            public void configure() throws Exception {
                from("direct:start").to("validator:pd:somefile.xsd").convertBodyTo(String.class).to("log:after").to("mock:result");

            }
        };
    }

    private class Sender implements Runnable {

        private final String message = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" + //
                                       "<p:TestMessage xmlns:p=\"http://apache.camel.org/test\">" + //
                                       "<MessageContent>MessageContent</MessageContent>" + //
                                       "</p:TestMessage>";

        private final byte[] messageBytes = message.getBytes(StandardCharsets.UTF_8);

        @Override
        public void run() {
            // send up to 5 messages
            for (int j = 0; j < 5; j++) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
                sendBody("direct:start", messageBytes);
            }
        }

    }

    private class ClearCache implements Runnable {

        @Override
        public void run() {
            try {
                // start later after the first sender
                // threads are running
                Thread.sleep(200);
                clearCachedSchema();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }

    }

    private void clearCachedSchema() throws Exception {
        Collection<Endpoint> endpoints = context.getEndpoints();
        for (Endpoint endpoint : endpoints) {
            LOG.info("Endpoint URI: " + endpoint.getEndpointUri());
            if (endpoint.getEndpointUri().startsWith("validator:")) {
                ValidatorEndpoint xsltEndpoint = (ValidatorEndpoint)endpoint;
                xsltEndpoint.clearCachedSchema();
                LOG.info("schema cache cleared");
            }
        }
    }

    /**
     * Class to simulate a change of the XSD document. During the first call of
     * the resource a XSD is returned which does not fit to the XML document. In
     * the second call a XSD fitting to the XML document is returned.
     */
    static class ClassResolverImpl extends DefaultClassResolver {

        private final String xsdtemplate1 = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" + //
                                            "<xsd:schema targetNamespace=\"http://apache.camel.org/test\" xmlns=\"http://apache.camel.org/test\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\">"
                                            + //
                                            "    <xsd:complexType name=\"TestMessage\">" + //
                                            "        <xsd:sequence>" + //
                                            "            <xsd:element name=\"Content\" type=\"xsd:string\" />" + // //
                                                                                                                 // wrong
                                                                                                                 // element
                                                                                                                 // name
                                                                                                                 // will
                                                                                                                 // cause
                                                                                                                 // the
                                                                                                                 // validation
                                                                                                                 // to
                                                                                                                 // fail
        "        </xsd:sequence>" + //
                                            "        <xsd:attribute name=\"attr\" type=\"xsd:string\" default=\"xsd1\"/>" + //
                                            "    </xsd:complexType>" + //
                                            "    <xsd:element name=\"TestMessage\" type=\"TestMessage\" />" + //
                                            "</xsd:schema>"; //

        private final String xsdtemplate2 = xsdtemplate1.replace("\"Content\"", "\"MessageContent\""); // correct
                                                                                                       // element
                                                                                                       // name
                                                                                                       // -->
                                                                                                       // validation
                                                                                                       // will
                                                                                                       // be
                                                                                                       // correct

        private byte[] xsd1 = xsdtemplate1.getBytes(StandardCharsets.UTF_8);

        private byte[] xsd2 = xsdtemplate2.getBytes(StandardCharsets.UTF_8);

        private volatile short counter;

        @Override
        public InputStream loadResourceAsStream(String uri) {
            if (uri.startsWith("pd:")) {
                byte[] xsd;
                if (counter == 0) {
                    xsd = xsd1;
                    LOG.info("resolved XSD1");
                } else {
                    xsd = xsd2;
                    LOG.info("resolved XSD2");
                }
                counter++;
                return new ByteArrayInputStream(xsd);
            } else {
                return super.loadResourceAsStream(uri);
            }
        }

    }

}