InterceptingHttpAccessor uses internal ArrayList for sorting

Also caches InterceptingClientHttpRequestFactory (if applicable)

Issue: SPR-16137

spring-web/src/main/java/org/springframework/http/client/support/HttpAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,11 +34,12 @@ import org.springframework.util.Assert;
  * such as the {@link ClientHttpRequestFactory} to operate on.
  *
  * <p>Not intended to be used directly.
- * See {@link org.springframework.web.client.RestTemplate}.
+ * See {@link org.springframework.web.client.RestTemplate} for an entry point.
  *
  * @author Arjen Poutsma
  * @author Juergen Hoeller
  * @since 3.0
+ * @see ClientHttpRequestFactory
  * @see org.springframework.web.client.RestTemplate
  */
 public abstract class HttpAccessor {
@@ -56,6 +57,7 @@ public abstract class HttpAccessor {
 	 * <p><b>Note that the standard JDK HTTP library does not support the HTTP PATCH method.
 	 * Configure the Apache HttpComponents or OkHttp request factory to enable PATCH.</b>
 	 * @see #createRequest(URI, HttpMethod)
+	 * @see SimpleClientHttpRequestFactory
 	 * @see org.springframework.http.client.HttpComponentsAsyncClientHttpRequestFactory
 	 * @see org.springframework.http.client.OkHttp3ClientHttpRequestFactory
 	 */

spring-web/src/main/java/org/springframework/http/client/support/InterceptingHttpAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,43 +23,83 @@ import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.client.InterceptingClientHttpRequestFactory;
+import org.springframework.lang.Nullable;
 import org.springframework.util.CollectionUtils;
 
 /**
- * Base class for {@link org.springframework.web.client.RestTemplate} and other HTTP accessing gateway helpers, adding
- * interceptor-related properties to {@link HttpAccessor}'s common properties.
+ * Base class for {@link org.springframework.web.client.RestTemplate}
+ * and other HTTP accessing gateway helpers, adding interceptor-related
+ * properties to {@link HttpAccessor}'s common properties.
  *
- * <p>Not intended to be used directly. See {@link org.springframework.web.client.RestTemplate}.
+ * <p>Not intended to be used directly.
+ * See {@link org.springframework.web.client.RestTemplate} for an entry point.
  *
  * @author Arjen Poutsma
+ * @author Juergen Hoeller
+ * @since 3.0
+ * @see ClientHttpRequestInterceptor
+ * @see InterceptingClientHttpRequestFactory
+ * @see org.springframework.web.client.RestTemplate
  */
 public abstract class InterceptingHttpAccessor extends HttpAccessor {
 
-	private List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
+	private final List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
+
+	@Nullable
+	private volatile ClientHttpRequestFactory interceptingRequestFactory;
+
 
 	/**
-	 * Sets the request interceptors that this accessor should use.
+	 * Set the request interceptors that this accessor should use.
+	 * <p>The interceptors will get sorted according to their order
+	 * once the {@link ClientHttpRequestFactory} will be built.
+	 * @see #getRequestFactory()
+	 * @see AnnotationAwareOrderComparator
 	 */
 	public void setInterceptors(List<ClientHttpRequestInterceptor> interceptors) {
-		AnnotationAwareOrderComparator.sort(interceptors);
-		this.interceptors = interceptors;
+		// Take getInterceptors() List as-is when passed in here
+		if (this.interceptors != interceptors) {
+			this.interceptors.clear();
+			this.interceptors.addAll(interceptors);
+			AnnotationAwareOrderComparator.sort(this.interceptors);
+		}
 	}
 
 	/**
-	 * Return the request interceptor that this accessor uses.
+	 * Return the request interceptors that this accessor uses.
+	 * <p>The returned {@link List} is active and may get appended to.
 	 */
 	public List<ClientHttpRequestInterceptor> getInterceptors() {
-		return interceptors;
+		return this.interceptors;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void setRequestFactory(ClientHttpRequestFactory requestFactory) {
+		super.setRequestFactory(requestFactory);
+		this.interceptingRequestFactory = null;
 	}
 
+	/**
+	 * Overridden to expose an {@link InterceptingClientHttpRequestFactory}
+	 * if necessary.
+	 * @see #getInterceptors()
+	 */
 	@Override
 	public ClientHttpRequestFactory getRequestFactory() {
-		ClientHttpRequestFactory delegate = super.getRequestFactory();
-		if (!CollectionUtils.isEmpty(getInterceptors())) {
-			return new InterceptingClientHttpRequestFactory(delegate, getInterceptors());
+		List<ClientHttpRequestInterceptor> interceptors = getInterceptors();
+		if (!CollectionUtils.isEmpty(interceptors)) {
+			ClientHttpRequestFactory factory = this.interceptingRequestFactory;
+			if (factory == null) {
+				factory = new InterceptingClientHttpRequestFactory(super.getRequestFactory(), interceptors);
+				this.interceptingRequestFactory = factory;
+			}
+			return factory;
 		}
 		else {
-			return delegate;
+			return super.getRequestFactory();
 		}
 	}
 

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -237,7 +237,8 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 	}
 
 	/**
-	 * Return the message body converters.
+	 * Return the list of message body converters.
+	 * <p>The returned {@link List} is active and may get appended to.
 	 */
 	public List<HttpMessageConverter<?>> getMessageConverters() {
 		return this.messageConverters;

spring-web/src/test/java/org/springframework/http/client/support/InterceptingHttpAccessorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,9 +16,6 @@
 
 package org.springframework.http.client.support;
 
-import static org.junit.Assert.*;
-
-import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
 
@@ -32,6 +29,8 @@ import org.springframework.http.client.ClientHttpRequestExecution;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.client.ClientHttpResponse;
 
+import static org.junit.Assert.*;
+
 /**
  * Tests for {@link InterceptingHttpAccessor}.
  *
@@ -40,7 +39,7 @@ import org.springframework.http.client.ClientHttpResponse;
 public class InterceptingHttpAccessorTests {
 
 	@Test
-	public void getInterceptors() throws Exception {
+	public void getInterceptors() {
 		TestInterceptingHttpAccessor accessor = new TestInterceptingHttpAccessor();
 		List<ClientHttpRequestInterceptor> interceptors = Arrays.asList(
 				new SecondClientHttpRequestInterceptor(),
@@ -55,22 +54,25 @@ public class InterceptingHttpAccessorTests {
 		assertThat(accessor.getInterceptors().get(2), Matchers.instanceOf(ThirdClientHttpRequestInterceptor.class));
 	}
 
+
 	private class TestInterceptingHttpAccessor extends InterceptingHttpAccessor {
 	}
 
+
 	@Order(1)
 	private class FirstClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {
+
 		@Override
-		public ClientHttpResponse intercept(HttpRequest request, byte[] body,
-				ClientHttpRequestExecution execution) throws IOException {
+		public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) {
 			return null;
 		}
 	}
 
+
 	private class SecondClientHttpRequestInterceptor implements ClientHttpRequestInterceptor, Ordered {
+
 		@Override
-		public ClientHttpResponse intercept(HttpRequest request, byte[] body,
-				ClientHttpRequestExecution execution) throws IOException {
+		public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) {
 			return null;
 		}
 
@@ -80,12 +82,13 @@ public class InterceptingHttpAccessorTests {
 		}
 	}
 
+
 	private class ThirdClientHttpRequestInterceptor implements ClientHttpRequestInterceptor {
+
 		@Override
-		public ClientHttpResponse intercept(HttpRequest request, byte[] body,
-				ClientHttpRequestExecution execution) throws IOException {
+		public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) {
 			return null;
 		}
 	}
 
-}
+}