✨ Built-in buffering support in RestClient

integration-tests/src/test/java/infra/web/client/config/RestTemplateBuilderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2024 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

today-test/src/main/java/infra/test/web/client/MockRestServiceServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2024 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

today-web/src/main/java/infra/http/client/BufferingClientHttpRequestFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2024 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -19,8 +19,11 @@
 
 import java.io.IOException;
 import java.net.URI;
+import java.util.function.Predicate;
 
 import infra.http.HttpMethod;
+import infra.http.HttpRequest;
+import infra.lang.Nullable;
 
 /**
  * Wrapper for a {@link ClientHttpRequestFactory} that buffers
@@ -35,19 +38,33 @@
  */
 public class BufferingClientHttpRequestFactory extends ClientHttpRequestFactoryWrapper {
 
+  private final Predicate<HttpRequest> bufferingPredicate;
+
   /**
    * Create a buffering wrapper for the given {@link ClientHttpRequestFactory}.
    *
    * @param requestFactory the target request factory to wrap
    */
   public BufferingClientHttpRequestFactory(ClientHttpRequestFactory requestFactory) {
+    this(requestFactory, null);
+  }
+
+  /**
+   * Constructor variant with an additional predicate to decide whether to
+   * buffer the response.
+   *
+   * @since 5.0
+   */
+  public BufferingClientHttpRequestFactory(ClientHttpRequestFactory requestFactory,
+          @Nullable Predicate<HttpRequest> bufferingPredicate) {
     super(requestFactory);
+    this.bufferingPredicate = bufferingPredicate != null ? bufferingPredicate : request -> true;
   }
 
   @Override
   protected ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod, ClientHttpRequestFactory requestFactory) throws IOException {
     ClientHttpRequest request = requestFactory.createRequest(uri, httpMethod);
-    if (shouldBuffer(uri, httpMethod)) {
+    if (shouldBuffer(request)) {
       return new BufferingClientHttpRequestWrapper(request);
     }
     else {
@@ -61,12 +78,11 @@ protected ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod, Client
    * <p>The default implementation returns {@code true} for all URIs and methods.
    * Subclasses can override this method to change this behavior.
    *
-   * @param uri the URI
-   * @param httpMethod the method
+   * @param request the request
    * @return {@code true} if the exchange should be buffered; {@code false} otherwise
    */
-  protected boolean shouldBuffer(URI uri, HttpMethod httpMethod) {
-    return true;
+  protected boolean shouldBuffer(HttpRequest request) {
+    return this.bufferingPredicate.test(request);
   }
 
 }

today-web/src/main/java/infra/http/client/InterceptingClientHttpRequest.java

@@ -20,6 +20,7 @@
 import java.io.IOException;
 import java.net.URI;
 import java.util.List;
+import java.util.function.Predicate;
 
 import infra.http.HttpHeaders;
 import infra.http.HttpMethod;
@@ -43,13 +44,16 @@ final class InterceptingClientHttpRequest extends AbstractBufferingClientHttpReq
 
   private final List<ClientHttpRequestInterceptor> interceptors;
 
+  private final Predicate<HttpRequest> bufferingPredicate;
+
   InterceptingClientHttpRequest(ClientHttpRequestFactory requestFactory,
-          List<ClientHttpRequestInterceptor> interceptors, URI uri, HttpMethod method) {
+          List<ClientHttpRequestInterceptor> interceptors, URI uri, HttpMethod method, Predicate<HttpRequest> bufferingPredicate) {
 
     this.requestFactory = requestFactory;
     this.interceptors = interceptors;
     this.method = method;
     this.uri = uri;
+    this.bufferingPredicate = bufferingPredicate;
   }
 
   @Override
@@ -103,7 +107,7 @@ public ClientHttpResponse execute(HttpRequest request, byte[] body) throws IOExc
   }
 
   private boolean shouldBufferResponse(HttpRequest request) {
-    return false;
+    return bufferingPredicate.test(request);
   }
 
 }

today-web/src/main/java/infra/http/client/InterceptingClientHttpRequestFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2023 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -12,16 +12,18 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see [http://www.gnu.org/licenses/]
+ * along with this program. If not, see [https://www.gnu.org/licenses/]
  */
 
 package infra.http.client;
 
 import java.net.URI;
 import java.util.Collections;
 import java.util.List;
+import java.util.function.Predicate;
 
 import infra.http.HttpMethod;
+import infra.http.HttpRequest;
 import infra.lang.Nullable;
 
 /**
@@ -38,22 +40,38 @@ public class InterceptingClientHttpRequestFactory extends ClientHttpRequestFacto
 
   private final List<ClientHttpRequestInterceptor> interceptors;
 
+  private final Predicate<HttpRequest> bufferingPredicate;
+
   /**
    * Create a new instance of the {@code InterceptingClientHttpRequestFactory} with the given parameters.
    *
    * @param requestFactory the request factory to wrap
    * @param interceptors the interceptors that are to be applied (can be {@code null})
    */
   public InterceptingClientHttpRequestFactory(ClientHttpRequestFactory requestFactory,
-      @Nullable List<ClientHttpRequestInterceptor> interceptors) {
+          @Nullable List<ClientHttpRequestInterceptor> interceptors) {
+
+    this(requestFactory, interceptors, null);
+  }
+
+  /**
+   * Constructor variant with an additional predicate to decide whether to
+   * buffer the response.
+   *
+   * @since 5.0
+   */
+  public InterceptingClientHttpRequestFactory(ClientHttpRequestFactory requestFactory,
+          @Nullable List<ClientHttpRequestInterceptor> interceptors,
+          @Nullable Predicate<HttpRequest> bufferingPredicate) {
 
     super(requestFactory);
     this.interceptors = interceptors != null ? interceptors : Collections.emptyList();
+    this.bufferingPredicate = bufferingPredicate != null ? bufferingPredicate : req -> false;
   }
 
   @Override
   protected ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod, ClientHttpRequestFactory requestFactory) {
-    return new InterceptingClientHttpRequest(requestFactory, this.interceptors, uri, httpMethod);
+    return new InterceptingClientHttpRequest(requestFactory, this.interceptors, uri, httpMethod, bufferingPredicate);
   }
 
 }

today-web/src/main/java/infra/http/client/support/HttpAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2024 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,14 +21,18 @@
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Predicate;
 
 import infra.core.annotation.AnnotationAwareOrderComparator;
 import infra.http.HttpMethod;
+import infra.http.HttpRequest;
+import infra.http.client.BufferingClientHttpRequestFactory;
 import infra.http.client.ClientHttpRequest;
 import infra.http.client.ClientHttpRequestFactory;
 import infra.http.client.ClientHttpRequestInitializer;
 import infra.http.client.JdkClientHttpRequestFactory;
 import infra.lang.Assert;
+import infra.lang.Nullable;
 import infra.logging.Logger;
 import infra.logging.LoggerFactory;
 
@@ -54,9 +58,12 @@ public abstract class HttpAccessor {
   /** Logger available to subclasses. */
   protected final Logger logger = LoggerFactory.getLogger(getClass());
 
+  private final ArrayList<ClientHttpRequestInitializer> httpRequestInitializers = new ArrayList<>();
+
   private ClientHttpRequestFactory requestFactory = new JdkClientHttpRequestFactory();
 
-  private final ArrayList<ClientHttpRequestInitializer> httpRequestInitializers = new ArrayList<>();
+  @Nullable
+  private Predicate<HttpRequest> bufferingPredicate;
 
   /**
    * Set the request factory that this accessor uses for obtaining client request handles.
@@ -78,7 +85,8 @@ public void setRequestFactory(ClientHttpRequestFactory requestFactory) {
    * Return the request factory that this accessor uses for obtaining client request handles.
    */
   public ClientHttpRequestFactory getRequestFactory() {
-    return this.requestFactory;
+    return this.bufferingPredicate != null ? new BufferingClientHttpRequestFactory(
+            this.requestFactory, this.bufferingPredicate) : this.requestFactory;
   }
 
   /**
@@ -87,7 +95,6 @@ public ClientHttpRequestFactory getRequestFactory() {
    * {@linkplain AnnotationAwareOrderComparator#sort(List) order}.
    */
   public void setHttpRequestInitializers(List<ClientHttpRequestInitializer> requestInitializers) {
-
     if (this.httpRequestInitializers != requestInitializers) {
       this.httpRequestInitializers.clear();
       this.httpRequestInitializers.addAll(requestInitializers);
@@ -109,6 +116,28 @@ public List<ClientHttpRequestInitializer> getHttpRequestInitializers() {
     return this.httpRequestInitializers;
   }
 
+  /**
+   * Enable buffering of request and response, aggregating all content before
+   * it is sent, and making it possible to read the response body repeatedly.
+   *
+   * @param predicate to determine whether to buffer for the given request
+   * @since 5.0
+   */
+  public void setBufferingPredicate(@Nullable Predicate<HttpRequest> predicate) {
+    this.bufferingPredicate = predicate;
+  }
+
+  /**
+   * Return the {@link #setBufferingPredicate(Predicate) configured} predicate
+   * to determine whether to buffer request and response content.
+   *
+   * @since 5.0
+   */
+  @Nullable
+  public Predicate<HttpRequest> getBufferingPredicate() {
+    return this.bufferingPredicate;
+  }
+
   /**
    * Create a new {@link ClientHttpRequest} via this template's {@link ClientHttpRequestFactory}.
    *

today-web/src/main/java/infra/http/client/support/InterceptingHttpAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2023 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -12,7 +12,7 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see [http://www.gnu.org/licenses/]
+ * along with this program. If not, see [https://www.gnu.org/licenses/]
  */
 
 package infra.http.client.support;
@@ -125,7 +125,8 @@ public ClientHttpRequestFactory getRequestFactory() {
         synchronized(this) {
           factory = this.interceptingRequestFactory;
           if (factory == null) {
-            factory = new InterceptingClientHttpRequestFactory(super.getRequestFactory(), interceptors);
+            factory = new InterceptingClientHttpRequestFactory(
+                    super.getRequestFactory(), interceptors, getBufferingPredicate());
             this.interceptingRequestFactory = factory;
           }
         }

today-web/src/main/java/infra/web/client/DefaultRestClient.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2024 the original author or authors.
+ * Copyright 2017 - 2025 the original author or authors.
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -44,6 +44,7 @@
 import infra.http.MediaType;
 import infra.http.ResponseEntity;
 import infra.http.StreamingHttpOutputMessage;
+import infra.http.client.BufferingClientHttpRequestFactory;
 import infra.http.client.ClientHttpRequest;
 import infra.http.client.ClientHttpRequestFactory;
 import infra.http.client.ClientHttpRequestInitializer;
@@ -110,13 +111,17 @@ final class DefaultRestClient implements RestClient {
 
   private final boolean detectEmptyMessageBody;
 
+  @Nullable
+  private final Predicate<HttpRequest> bufferingPredicate;
+
   DefaultRestClient(ClientHttpRequestFactory clientRequestFactory,
           @Nullable List<ClientHttpRequestInterceptor> interceptors,
           @Nullable List<ClientHttpRequestInitializer> initializers,
           UriBuilderFactory uriBuilderFactory, @Nullable HttpHeaders defaultHeaders,
           @Nullable MultiValueMap<String, String> defaultCookies,
           @Nullable Consumer<RequestHeadersSpec<?>> defaultRequest,
           @Nullable List<ResponseErrorHandler> statusHandlers,
+          @Nullable Predicate<HttpRequest> bufferingPredicate,
           List<HttpMessageConverter<?>> messageConverters, DefaultRestClientBuilder builder,
           boolean ignoreStatusHandlers, boolean detectEmptyMessageBody) {
 
@@ -128,6 +133,7 @@ final class DefaultRestClient implements RestClient {
     this.defaultCookies = defaultCookies;
     this.defaultRequest = defaultRequest;
     this.defaultStatusHandlers = statusHandlers;
+    this.bufferingPredicate = bufferingPredicate;
     this.messageConverters = messageConverters;
     this.builder = builder;
     this.defaultStatusHandler = StatusHandler.defaultHandler(messageConverters);
@@ -603,10 +609,14 @@ private ClientHttpRequest createRequest(URI uri) throws ResourceAccessException
       if (interceptors != null) {
         factory = interceptingRequestFactory;
         if (factory == null) {
-          factory = new InterceptingClientHttpRequestFactory(clientRequestFactory, interceptors);
+          factory = new InterceptingClientHttpRequestFactory(
+                  clientRequestFactory, interceptors, bufferingPredicate);
           interceptingRequestFactory = factory;
         }
       }
+      else if (bufferingPredicate != null) {
+        factory = new BufferingClientHttpRequestFactory(clientRequestFactory, bufferingPredicate);
+      }
       else {
         factory = clientRequestFactory;
       }