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 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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import com.sun.net.httpserver.HttpServer;

import com.sun.net.httpserver.HttpsConfigurator;

import com.sun.net.httpserver.HttpsServer;

import jdk.test.lib.net.SimpleSSLContext;

import org.testng.annotations.AfterTest;

import org.testng.annotations.AfterClass;

import org.testng.annotations.BeforeTest;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

import javax.net.ssl.SSLContext;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.UncheckedIOException;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.URI;

import java.net.http.HttpClient;

import java.net.http.HttpHeaders;

import java.net.http.HttpRequest;

import java.net.http.HttpResponse;

import java.net.http.HttpResponse.BodyHandler;

import java.net.http.HttpResponse.BodyHandlers;

import java.net.http.HttpResponse.BodySubscriber;

import java.nio.ByteBuffer;

import java.nio.charset.StandardCharsets;

import java.util.EnumSet;

import java.util.List;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.CompletionStage;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.concurrent.Executor;

import java.util.concurrent.Executors;

import java.util.concurrent.Flow;

import java.util.concurrent.atomic.AtomicLong;

import java.util.function.Consumer;

import java.util.function.Predicate;

import java.util.function.Supplier;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import static java.lang.System.out;

import static java.lang.String.format;

import static java.nio.charset.StandardCharsets.UTF_8;

import static org.testng.Assert.assertEquals;

import static org.testng.Assert.assertTrue;

public abstract class AbstractThrowingSubscribers implements HttpServerAdapters {

    SSLContext sslContext;

    HttpTestServer httpTestServer;    // HTTP/1.1    [ 4 servers ]

    HttpTestServer httpsTestServer;   // HTTPS/1.1

    HttpTestServer http2TestServer;   // HTTP/2 ( h2c )

    HttpTestServer https2TestServer;  // HTTP/2 ( h2  )

    String httpURI_fixed;

    String httpURI_chunk;

    String httpsURI_fixed;

    String httpsURI_chunk;

    String http2URI_fixed;

    String http2URI_chunk;

    String https2URI_fixed;

    String https2URI_chunk;

    static final int ITERATION_COUNT = 1;

    // a shared executor helps reduce the amount of threads created by the test

    static final Executor executor = new TestExecutor(Executors.newCachedThreadPool());

    static final ConcurrentMap<String, Throwable> FAILURES = new ConcurrentHashMap<>();

    static volatile boolean tasksFailed;

    static final AtomicLong serverCount = new AtomicLong();

    static final AtomicLong clientCount = new AtomicLong();

    static final long start = System.nanoTime();

    public static String now() {

        long now = System.nanoTime() - start;

        long secs = now / 1000_000_000;

        long mill = (now % 1000_000_000) / 1000_000;

        long nan = now % 1000_000;

        return String.format("[%d s, %d ms, %d ns] ", secs, mill, nan);

    }

    final ReferenceTracker TRACKER = ReferenceTracker.INSTANCE;

    private volatile HttpClient sharedClient;

    static class TestExecutor implements Executor {

        final AtomicLong tasks = new AtomicLong();

        Executor executor;

        TestExecutor(Executor executor) {

            this.executor = executor;

        }

        @Override

        public void execute(Runnable command) {

            long id = tasks.incrementAndGet();

            executor.execute(() -> {

                try {

                    command.run();

                } catch (Throwable t) {

                    tasksFailed = true;

                    System.out.printf(now() + "Task %s failed: %s%n", id, t);

                    System.err.printf(now() + "Task %s failed: %s%n", id, t);

                    FAILURES.putIfAbsent("Task " + id, t);

                    throw t;

                }

            });

        }

    }

    @AfterClass

    static final void printFailedTests() {

        out.println("\n=========================");

        try {

            out.printf("%n%sCreated %d servers and %d clients%n",

                    now(), serverCount.get(), clientCount.get());

            if (FAILURES.isEmpty()) return;

            out.println("Failed tests: ");

            FAILURES.entrySet().forEach((e) -> {

                out.printf("\t%s: %s%n", e.getKey(), e.getValue());

                e.getValue().printStackTrace(out);

                e.getValue().printStackTrace();

            });

            if (tasksFailed) {

                System.out.println("WARNING: Some tasks failed");

            }

        } finally {

            out.println("\n=========================\n");

        }

    }

    private String[] uris() {

        return new String[] {

                httpURI_fixed,

                httpURI_chunk,

                httpsURI_fixed,

                httpsURI_chunk,

                http2URI_fixed,

                http2URI_chunk,

                https2URI_fixed,

                https2URI_chunk,

        };

    }

    static AtomicLong URICOUNT = new AtomicLong();

    @DataProvider(name = "sanity")

    public Object[][] sanity() {

        String[] uris = uris();

        Object[][] result = new Object[uris.length * 2][];

        int i = 0;

        for (boolean sameClient : List.of(false, true)) {

            for (String uri: uris()) {

                result[i++] = new Object[] {uri, sameClient};

            }

        }

        assert i == uris.length * 2;

        return result;

    }

    @DataProvider(name = "variants")

    public Object[][] variants() {

        String[] uris = uris();

        Object[][] result = new Object[uris.length * 2 * 2][];

        int i = 0;

        for (Thrower thrower : List.of(

                new UncheckedIOExceptionThrower(),

                new UncheckedCustomExceptionThrower())) {

            for (boolean sameClient : List.of(false, true)) {

                for (String uri : uris()) {

                    result[i++] = new Object[]{uri, sameClient, thrower};

                }

            }

        }

        assert i == uris.length * 2 * 2;

        return result;

    }

    private HttpClient makeNewClient() {

        clientCount.incrementAndGet();

        HttpClient client =  HttpClient.newBuilder()

                .proxy(HttpClient.Builder.NO_PROXY)

                .executor(executor)

                .sslContext(sslContext)

                .build();

        return TRACKER.track(client);

    }

    HttpClient newHttpClient(boolean share) {

        if (!share) return makeNewClient();

        HttpClient shared = sharedClient;

        if (shared != null) return shared;

        synchronized (this) {

            shared = sharedClient;

            if (shared == null) {

                shared = sharedClient = makeNewClient();

            }

            return shared;

        }

    }

    enum SubscriberType {

        INLINE,  // In line subscribers complete their CF on ON_COMPLETE

                 // e.g. BodySubscribers::ofString

        OFFLINE; // Off line subscribers complete their CF immediately

                 // but require the client to pull the data after the

                 // CF completes (e.g. BodySubscribers::ofInputStream)

    }

    static EnumSet<Where> excludes(SubscriberType type) {

        EnumSet<Where> set = EnumSet.noneOf(Where.class);

        if (type == SubscriberType.OFFLINE) {

            // Throwing on onSubscribe needs some more work

            // for the case of InputStream, where the body has already

            // completed by the time the subscriber is subscribed.

            // The only way we have at that point to relay the exception

            // is to call onError on the subscriber, but should we if

            // Subscriber::onSubscribed has thrown an exception and

            // not completed normally?

            set.add(Where.ON_SUBSCRIBE);

        }

        // Don't know how to make the stack reliably cause onError

        // to be called without closing the connection.

        // And how do we get the exception if onError throws anyway?

        set.add(Where.ON_ERROR);

        return set;

    }

    //@Test(dataProvider = "sanity")

    protected void testSanityImpl(String uri, boolean sameClient)

            throws Exception {

        HttpClient client = null;

        String uri2 = uri + "-" + URICOUNT.incrementAndGet() + "/sanity";

        out.printf("%ntestSanity(%s, %b)%n", uri2, sameClient);

        for (int i=0; i< ITERATION_COUNT; i++) {

            if (!sameClient || client == null)

                client = newHttpClient(sameClient);

            HttpRequest req = HttpRequest.newBuilder(URI.create(uri2))

                    .build();

            BodyHandler<String> handler =

                    new ThrowingBodyHandler((w) -> {},

                                            BodyHandlers.ofString());

            HttpResponse<String> response = client.send(req, handler);

            String body = response.body();

            assertEquals(URI.create(body).getPath(), URI.create(uri2).getPath());

        }

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsStringImpl(String uri,

                                     boolean sameClient,

                                     Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test = format("testThrowingAsString(%s, %b, %s)",

                             uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofString,

                this::shouldHaveThrown, thrower,false,

                excludes(SubscriberType.INLINE));

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsLinesImpl(String uri,

                                    boolean sameClient,

                                    Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test =  format("testThrowingAsLines(%s, %b, %s)",

                uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofLines,

                this::checkAsLines, thrower,false,

                excludes(SubscriberType.OFFLINE));

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsInputStreamImpl(String uri,

                                          boolean sameClient,

                                          Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test = format("testThrowingAsInputStream(%s, %b, %s)",

                uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofInputStream,

                this::checkAsInputStream,  thrower,false,

                excludes(SubscriberType.OFFLINE));

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsStringAsyncImpl(String uri,

                                          boolean sameClient,

                                          Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test = format("testThrowingAsStringAsync(%s, %b, %s)",

                uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofString,

                     this::shouldHaveThrown, thrower, true,

                excludes(SubscriberType.INLINE));

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsLinesAsyncImpl(String uri,

                                         boolean sameClient,

                                         Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test = format("testThrowingAsLinesAsync(%s, %b, %s)",

                uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofLines,

                this::checkAsLines, thrower,true,

                excludes(SubscriberType.OFFLINE));

    }

    //@Test(dataProvider = "variants")

    protected void testThrowingAsInputStreamAsyncImpl(String uri,

                                               boolean sameClient,

                                               Thrower thrower)

            throws Exception

    {

        uri = uri + "-" + URICOUNT.incrementAndGet();

        String test = format("testThrowingAsInputStreamAsync(%s, %b, %s)",

                uri, sameClient, thrower);

        testThrowing(test, uri, sameClient, BodyHandlers::ofInputStream,

                this::checkAsInputStream, thrower,true,

                excludes(SubscriberType.OFFLINE));

    }

    private <T,U> void testThrowing(String name, String uri, boolean sameClient,

                                    Supplier<BodyHandler<T>> handlers,

                                    Finisher finisher, Thrower thrower,

                                    boolean async, EnumSet<Where> excludes)

            throws Exception

    {

        out.printf("%n%s%s%n", now(), name);

        try {

            testThrowing(uri, sameClient, handlers, finisher, thrower, async, excludes);

        } catch (Error | Exception x) {

            FAILURES.putIfAbsent(name, x);

            throw x;

        }

    }

    private <T,U> void testThrowing(String uri, boolean sameClient,

                                    Supplier<BodyHandler<T>> handlers,

                                    Finisher finisher, Thrower thrower,

                                    boolean async,

                                    EnumSet<Where> excludes)

            throws Exception

    {

        HttpClient client = null;

        for (Where where : EnumSet.complementOf(excludes)) {

            if (!sameClient || client == null)

                client = newHttpClient(sameClient);

            String uri2 = uri + "-" + where;

            HttpRequest req = HttpRequest.

                    newBuilder(URI.create(uri2))

                    .build();

            BodyHandler<T> handler =

                    new ThrowingBodyHandler(where.select(thrower), handlers.get());

            System.out.println("try throwing in " + where);

            HttpResponse<T> response = null;

            if (async) {

                try {

                    response = client.sendAsync(req, handler).join();

                } catch (Error | Exception x) {

                    Throwable cause = findCause(x, thrower);

                    if (cause == null) throw causeNotFound(where, x);

                    System.out.println(now() + "Got expected exception: " + cause);

                }

            } else {

                try {

                    response = client.send(req, handler);

                } catch (Error | Exception t) {

                    // synchronous send will rethrow exceptions

                    Throwable throwable = t.getCause();

                    assert throwable != null;

                    if (thrower.test(throwable)) {

                        System.out.println(now() + "Got expected exception: " + throwable);

                    } else throw causeNotFound(where, t);

                }

            }

            if (response != null) {

                finisher.finish(where, response, thrower);

            }

        }

    }

    enum Where {

        BODY_HANDLER, ON_SUBSCRIBE, ON_NEXT, ON_COMPLETE, ON_ERROR, GET_BODY, BODY_CF;

        public Consumer<Where> select(Consumer<Where> consumer) {

            return new Consumer<Where>() {

                @Override

                public void accept(Where where) {

                    if (Where.this == where) {

                        consumer.accept(where);

                    }

                }

            };

        }

    }

    static AssertionError causeNotFound(Where w, Throwable t) {

        return new AssertionError("Expected exception not found in " + w, t);

    }

    interface Thrower extends Consumer<Where>, Predicate<Throwable> {

    }

    interface Finisher<T,U> {

        U finish(Where w, HttpResponse<T> resp, Thrower thrower) throws IOException;

    }

    final <T,U> U shouldHaveThrown(Where w, HttpResponse<T> resp, Thrower thrower) {

        String msg = "Expected exception not thrown in " + w

                + "\n\tReceived: " + resp

                + "\n\tWith body: " + resp.body();

        System.out.println(msg);

        throw new RuntimeException(msg);

    }

    final List<String> checkAsLines(Where w, HttpResponse<Stream<String>> resp, Thrower thrower) {

        switch(w) {

            case BODY_HANDLER: return shouldHaveThrown(w, resp, thrower);

            case GET_BODY: return shouldHaveThrown(w, resp, thrower);

            case BODY_CF: return shouldHaveThrown(w, resp, thrower);

            default: break;

        }

        List<String> result = null;

        try {

            result = resp.body().collect(Collectors.toList());

        } catch (Error | Exception x) {

            Throwable cause = findCause(x, thrower);

            if (cause != null) {

                out.println(now() + "Got expected exception in " + w + ": " + cause);

                return result;

            }

            throw causeNotFound(w, x);

        }

        return shouldHaveThrown(w, resp, thrower);

    }

    final List<String> checkAsInputStream(Where w, HttpResponse<InputStream> resp,

                                    Thrower thrower)

            throws IOException

    {

        switch(w) {

            case BODY_HANDLER: return shouldHaveThrown(w, resp, thrower);

            case GET_BODY: return shouldHaveThrown(w, resp, thrower);

            case BODY_CF: return shouldHaveThrown(w, resp, thrower);

            default: break;

        }

        List<String> result = null;

        try (InputStreamReader r1 = new InputStreamReader(resp.body(), UTF_8);

             BufferedReader r = new BufferedReader(r1)) {

            try {

                result = r.lines().collect(Collectors.toList());

            } catch (Error | Exception x) {

                Throwable cause = findCause(x, thrower);

                if (cause != null) {

                    out.println(now() + "Got expected exception in " + w + ": " + cause);

                    return result;

                }

                throw causeNotFound(w, x);

            }

        }

        return shouldHaveThrown(w, resp, thrower);

    }

    private static Throwable findCause(Throwable x,

                                       Predicate<Throwable> filter) {

        while (x != null && !filter.test(x)) x = x.getCause();

        return x;

    }

    static final class UncheckedCustomExceptionThrower implements Thrower {

        @Override

        public void accept(Where where) {

            out.println(now() + "Throwing in " + where);

            throw new UncheckedCustomException(where.name());

        }

        @Override

        public boolean test(Throwable throwable) {

            return UncheckedCustomException.class.isInstance(throwable);

        }

        @Override

        public String toString() {