Add custom ExchangeId generator support

httpclient5/src/main/java/org/apache/hc/client5/http/ExchangeIdGenerator.java

@@ -0,0 +1,49 @@
+/*
+ * ====================================================================
+ * 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.client5.http;
+
+import org.apache.hc.core5.annotation.Contract;
+import org.apache.hc.core5.annotation.ThreadingBehavior;
+
+/**
+ * Generates exchange identifiers for message exchanges.
+ *
+ * @since 5.7
+ */
+@Contract(threading = ThreadingBehavior.STATELESS)
+public interface ExchangeIdGenerator {
+
+    /**
+     * Generates the next exchange identifier.
+     * <p>
+     * The returned identifier must be unique, non-null, and non-blank.
+     * </p>
+     *
+     * @return the next exchange identifier
+     */
+    String getNextExchangeId();
+}

httpclient5/src/main/java/org/apache/hc/client5/http/impl/DefaultExechangeIdGenerator.java

@@ -0,0 +1,47 @@
+/*
+ * ====================================================================
+ * 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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+package org.apache.hc.client5.http.impl;
+
+import org.apache.hc.client5.http.ExchangeIdGenerator;
+import org.apache.hc.core5.annotation.Contract;
+import org.apache.hc.core5.annotation.ThreadingBehavior;
+
+/**
+ * The default implementation of {@link ExchangeIdGenerator}.
+ *
+ * @since 5.7
+ */
+@Contract(threading = ThreadingBehavior.STATELESS)
+public class DefaultExechangeIdGenerator implements ExchangeIdGenerator {
+
+    public static final ExchangeIdGenerator INSTANCE = new DefaultExechangeIdGenerator();
+
+    @Override
+    public String getNextExchangeId() {
+        return ExecSupport.getNextExchangeId();
+    }
+}

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/H2AsyncClientBuilder.java

@@ -37,6 +37,7 @@
 
 import org.apache.hc.client5.http.AuthenticationStrategy;
 import org.apache.hc.client5.http.DnsResolver;
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRequestRetryStrategy;
 import org.apache.hc.client5.http.SchemePortResolver;
 import org.apache.hc.client5.http.async.AsyncExecChainHandler;
@@ -51,6 +52,7 @@
 import org.apache.hc.client5.http.impl.ChainElement;
 import org.apache.hc.client5.http.impl.CookieSpecSupport;
 import org.apache.hc.client5.http.impl.DefaultAuthenticationStrategy;
+import org.apache.hc.client5.http.impl.DefaultExechangeIdGenerator;
 import org.apache.hc.client5.http.impl.DefaultHttpRequestRetryStrategy;
 import org.apache.hc.client5.http.impl.DefaultRedirectStrategy;
 import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
@@ -182,6 +184,7 @@ private ExecInterceptorEntry(
     private LinkedList<ResponseInterceptorEntry> responseInterceptors;
     private LinkedList<ExecInterceptorEntry> execInterceptors;
 
+    private ExchangeIdGenerator exchangeIdGenerator;
     private HttpRoutePlanner routePlanner;
     private RedirectStrategy redirectStrategy;
     private HttpRequestRetryStrategy retryStrategy;
@@ -563,6 +566,17 @@ public final H2AsyncClientBuilder setDefaultHeaders(final Collection<? extends H
         return this;
     }
 
+    /**
+     * Sets {@link ExchangeIdGenerator} instance.
+     *
+     * @return this instance.
+     * @since 5.7
+     */
+    public final H2AsyncClientBuilder setExchangeIdGenerator(final ExchangeIdGenerator exchangeIdGenerator) {
+        this.exchangeIdGenerator = exchangeIdGenerator;
+        return this;
+    }
+
     /**
      * Sets {@link HttpRoutePlanner} instance.
      *
@@ -855,6 +869,11 @@ public CloseableHttpAsyncClient build() {
                     ChainElement.RETRY.name());
         }
 
+        ExchangeIdGenerator exchangeIdGeneratorCopy = this.exchangeIdGenerator;
+        if (exchangeIdGeneratorCopy == null) {
+            exchangeIdGeneratorCopy = DefaultExechangeIdGenerator.INSTANCE;
+        }
+
         HttpRoutePlanner routePlannerCopy = this.routePlanner;
         if (routePlannerCopy == null) {
             SchemePortResolver schemePortResolverCopy = this.schemePortResolver;
@@ -983,6 +1002,7 @@ public CloseableHttpAsyncClient build() {
                 pushConsumerRegistry,
                 threadFactory != null ? threadFactory : new DefaultThreadFactory("httpclient-main", true),
                 connPool,
+                exchangeIdGeneratorCopy,
                 routePlannerCopy,
                 cookieSpecRegistryCopy,
                 authSchemeRegistryCopy,

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java

@@ -42,6 +42,7 @@
 import org.apache.hc.client5.http.AuthenticationStrategy;
 import org.apache.hc.client5.http.ConnectionKeepAliveStrategy;
 import org.apache.hc.client5.http.EarlyHintsListener;
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRequestRetryStrategy;
 import org.apache.hc.client5.http.SchemePortResolver;
 import org.apache.hc.client5.http.UserTokenHandler;
@@ -59,6 +60,7 @@
 import org.apache.hc.client5.http.impl.DefaultAuthenticationStrategy;
 import org.apache.hc.client5.http.impl.DefaultClientConnectionReuseStrategy;
 import org.apache.hc.client5.http.impl.DefaultConnectionKeepAliveStrategy;
+import org.apache.hc.client5.http.impl.DefaultExechangeIdGenerator;
 import org.apache.hc.client5.http.impl.DefaultHttpRequestRetryStrategy;
 import org.apache.hc.client5.http.impl.DefaultRedirectStrategy;
 import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
@@ -233,6 +235,7 @@ private ExecInterceptorEntry(
     private LinkedList<ResponseInterceptorEntry> responseInterceptors;
     private LinkedList<ExecInterceptorEntry> execInterceptors;
 
+    private ExchangeIdGenerator exchangeIdGenerator;
     private HttpRoutePlanner routePlanner;
     private RedirectStrategy redirectStrategy;
     private HttpRequestRetryStrategy retryStrategy;
@@ -695,6 +698,17 @@ public final HttpAsyncClientBuilder setProxy(final HttpHost proxy) {
         return this;
     }
 
+    /**
+     * Sets {@link ExchangeIdGenerator} instance.
+     *
+     * @return this instance.
+     * @since 5.7
+     */
+    public final HttpAsyncClientBuilder setExchangeIdGenerator(final ExchangeIdGenerator exchangeIdGenerator) {
+        this.exchangeIdGenerator = exchangeIdGenerator;
+        return this;
+    }
+
     /**
      * Sets {@link HttpRoutePlanner} instance.
      *
@@ -1140,6 +1154,10 @@ public CloseableHttpAsyncClient build() {
             execChainDefinition.addFirst(new TlsRequiredAsyncExec(), ChainElement.TLS_REQUIRED.name());
         }
 
+        ExchangeIdGenerator exchangeIdGeneratorCopy = this.exchangeIdGenerator;
+        if (exchangeIdGeneratorCopy == null) {
+            exchangeIdGeneratorCopy = DefaultExechangeIdGenerator.INSTANCE;
+        }
 
         HttpRoutePlanner routePlannerCopy = this.routePlanner;
         if (routePlannerCopy == null) {
@@ -1277,6 +1295,7 @@ public CloseableHttpAsyncClient build() {
                 pushConsumerRegistry,
                 threadFactory != null ? threadFactory : new DefaultThreadFactory("httpclient-main", true),
                 connManagerCopy,
+                exchangeIdGeneratorCopy,
                 routePlannerCopy,
                 tlsConfig,
                 cookieSpecRegistryCopy,

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalAbstractHttpAsyncClient.java

@@ -40,6 +40,7 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRoute;
 import org.apache.hc.client5.http.async.AsyncExecCallback;
 import org.apache.hc.client5.http.async.AsyncExecChain;
@@ -50,7 +51,6 @@
 import org.apache.hc.client5.http.config.RequestConfig;
 import org.apache.hc.client5.http.cookie.CookieSpecFactory;
 import org.apache.hc.client5.http.cookie.CookieStore;
-import org.apache.hc.client5.http.impl.ExecSupport;
 import org.apache.hc.client5.http.protocol.HttpClientContext;
 import org.apache.hc.client5.http.routing.RoutingSupport;
 import org.apache.hc.core5.concurrent.Cancellable;
@@ -88,6 +88,7 @@ abstract class InternalAbstractHttpAsyncClient extends AbstractHttpAsyncClientBa
     private static final Logger LOG = LoggerFactory.getLogger(InternalAbstractHttpAsyncClient.class);
 
     private final AsyncExecChainElement execChain;
+    private final ExchangeIdGenerator exchangeIdGenerator;
     private final Lookup<CookieSpecFactory> cookieSpecRegistry;
     private final Lookup<AuthSchemeFactory> authSchemeRegistry;
     private final CookieStore cookieStore;
@@ -103,6 +104,7 @@ abstract class InternalAbstractHttpAsyncClient extends AbstractHttpAsyncClientBa
             final AsyncPushConsumerRegistry pushConsumerRegistry,
             final ThreadFactory threadFactory,
             final AsyncExecChainElement execChain,
+            final ExchangeIdGenerator exchangeIdGenerator,
             final Lookup<CookieSpecFactory> cookieSpecRegistry,
             final Lookup<AuthSchemeFactory> authSchemeRegistry,
             final CookieStore cookieStore,
@@ -112,6 +114,7 @@ abstract class InternalAbstractHttpAsyncClient extends AbstractHttpAsyncClientBa
             final List<Closeable> closeables) {
         super(ioReactor, pushConsumerRegistry, threadFactory);
         this.execChain = execChain;
+        this.exchangeIdGenerator = exchangeIdGenerator;
         this.cookieSpecRegistry = cookieSpecRegistry;
         this.authSchemeRegistry = authSchemeRegistry;
         this.cookieStore = cookieStore;
@@ -232,7 +235,7 @@ protected <T> Future<T> doExecute(
                         resolvedTarget,
                         request,
                         clientContext);
-                final String exchangeId = ExecSupport.getNextExchangeId();
+                final String exchangeId = exchangeIdGenerator.getNextExchangeId();
                 clientContext.setExchangeId(exchangeId);
                 if (LOG.isDebugEnabled()) {
                     LOG.debug("{} preparing request execution", exchangeId);

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalH2AsyncClient.java

@@ -31,6 +31,7 @@
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRoute;
 import org.apache.hc.client5.http.async.AsyncExecRuntime;
 import org.apache.hc.client5.http.auth.AuthSchemeFactory;
@@ -79,6 +80,7 @@ public final class InternalH2AsyncClient extends InternalAbstractHttpAsyncClient
             final AsyncPushConsumerRegistry pushConsumerRegistry,
             final ThreadFactory threadFactory,
             final InternalH2ConnPool connPool,
+            final ExchangeIdGenerator exchangeIdGenerator,
             final HttpRoutePlanner routePlanner,
             final Lookup<CookieSpecFactory> cookieSpecRegistry,
             final Lookup<AuthSchemeFactory> authSchemeRegistry,
@@ -87,7 +89,7 @@ public final class InternalH2AsyncClient extends InternalAbstractHttpAsyncClient
             final RequestConfig defaultConfig,
             final List<Closeable> closeables,
             final int maxQueuedRequests) {
-        super(ioReactor, pushConsumerRegistry, threadFactory, execChain,
+        super(ioReactor, pushConsumerRegistry, threadFactory, execChain, exchangeIdGenerator,
                 cookieSpecRegistry, authSchemeRegistry, cookieStore, credentialsProvider, HttpClientContext::castOrCreate,
                 defaultConfig, closeables);
         this.connPool = connPool;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/InternalHttpAsyncClient.java

@@ -32,6 +32,7 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Function;
 
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRoute;
 import org.apache.hc.client5.http.async.AsyncExecRuntime;
 import org.apache.hc.client5.http.auth.AuthSchemeFactory;
@@ -85,6 +86,7 @@ public final class InternalHttpAsyncClient extends InternalAbstractHttpAsyncClie
             final AsyncPushConsumerRegistry pushConsumerRegistry,
             final ThreadFactory threadFactory,
             final AsyncClientConnectionManager manager,
+            final ExchangeIdGenerator exchangeIdGenerator,
             final HttpRoutePlanner routePlanner,
             final TlsConfig tlsConfig,
             final Lookup<CookieSpecFactory> cookieSpecRegistry,
@@ -95,7 +97,7 @@ public final class InternalHttpAsyncClient extends InternalAbstractHttpAsyncClie
             final RequestConfig defaultConfig,
             final List<Closeable> closeables,
             final int maxQueuedRequests) {
-        super(ioReactor, pushConsumerRegistry, threadFactory, execChain,
+        super(ioReactor, pushConsumerRegistry, threadFactory, execChain, exchangeIdGenerator,
                 cookieSpecRegistry, authSchemeRegistry, cookieStore, credentialsProvider, contextAdaptor,
                 defaultConfig, closeables);
         this.manager = manager;

httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/HttpClientBuilder.java

@@ -41,6 +41,7 @@
 
 import org.apache.hc.client5.http.AuthenticationStrategy;
 import org.apache.hc.client5.http.ConnectionKeepAliveStrategy;
+import org.apache.hc.client5.http.ExchangeIdGenerator;
 import org.apache.hc.client5.http.HttpRequestRetryStrategy;
 import org.apache.hc.client5.http.SchemePortResolver;
 import org.apache.hc.client5.http.UserTokenHandler;
@@ -61,6 +62,7 @@
 import org.apache.hc.client5.http.impl.DefaultAuthenticationStrategy;
 import org.apache.hc.client5.http.impl.DefaultClientConnectionReuseStrategy;
 import org.apache.hc.client5.http.impl.DefaultConnectionKeepAliveStrategy;
+import org.apache.hc.client5.http.impl.DefaultExechangeIdGenerator;
 import org.apache.hc.client5.http.impl.DefaultHttpRequestRetryStrategy;
 import org.apache.hc.client5.http.impl.DefaultRedirectStrategy;
 import org.apache.hc.client5.http.impl.DefaultSchemePortResolver;
@@ -194,6 +196,7 @@ private ExecInterceptorEntry(
     }
 
     private HttpRequestExecutor requestExec;
+    private ExchangeIdGenerator exchangeIdGenerator;
     private HttpClientConnectionManager connManager;
     private boolean connManagerShared;
     private SchemePortResolver schemePortResolver;
@@ -257,6 +260,17 @@ public final HttpClientBuilder setRequestExecutor(final HttpRequestExecutor requ
         return this;
     }
 
+    /**
+     * Sets {@link ExchangeIdGenerator} instance.
+     *
+     * @return this instance.
+     * @since 5.7
+     */
+    public final HttpClientBuilder setExchangeIdGenerator(final ExchangeIdGenerator exchangeIdGenerator) {
+        this.exchangeIdGenerator = exchangeIdGenerator;
+        return this;
+    }
+
     /**
      * Sets {@link HttpClientConnectionManager} instance.
      *
@@ -865,6 +879,10 @@ public CloseableHttpClient build() {
         if (requestExecCopy == null) {
             requestExecCopy = new HttpRequestExecutor();
         }
+        ExchangeIdGenerator exchangeIdGeneratorCopy = this.exchangeIdGenerator;
+        if (exchangeIdGeneratorCopy == null) {
+            exchangeIdGeneratorCopy = DefaultExechangeIdGenerator.INSTANCE;
+        }
         HttpClientConnectionManager connManagerCopy = this.connManager;
         if (connManagerCopy == null) {
             final PoolingHttpClientConnectionManagerBuilder connectionManagerBuilder = PoolingHttpClientConnectionManagerBuilder.create();
@@ -1139,6 +1157,7 @@ public CloseableHttpClient build() {
         return new InternalHttpClient(
                 connManagerCopy,
                 requestExecCopy,
+                exchangeIdGeneratorCopy,
                 execChain,
                 routePlannerCopy,
                 cookieSpecRegistryCopy,