Customize connection request timeout

Prior to this commit it was not possible to easily customize the
connection request timeout used by the HttpClient. Both
`HttpComponentsClientHttpRequestFactory` and
`HttpComponentsClientHttpRequestFactoryTests` have been updated to
support a `connectionRequestTimeout` property.

Issue: SPR-12166

Author: snicoll

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

@@ -61,6 +61,8 @@ public class HttpComponentsClientHttpRequestFactory implements ClientHttpRequest
 
 	private int connectTimeout;
 
+	private int connectionRequestTimeout;
+
 	private int socketTimeout;
 
 	private boolean bufferRequestBody = true;
@@ -139,6 +141,16 @@ private void setLegacyConnectionTimeout(HttpClient client, int timeout) {
 		}
 	}
 
+	/**
+	 * Set the timeout in milliseconds used when requesting a connection from the connection
+	 * manager using the underlying HttpClient.
+	 * A timeout value of 0 specifies an infinite timeout.
+	 * @param connectionRequestTimeout the timeout value to request a connection in milliseconds
+	 */
+	public void setConnectionRequestTimeout(int connectionRequestTimeout) {
+		this.connectionRequestTimeout = connectionRequestTimeout;
+	}
+
 	/**
 	 * Set the socket read timeout for the underlying HttpClient.
 	 * A timeout value of 0 specifies an infinite timeout.
@@ -193,9 +205,10 @@ public ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod) throws IO
 				config = ((Configurable) httpRequest).getConfig();
 			}
 			if (config == null) {
-				if (this.socketTimeout > 0 || this.connectTimeout > 0) {
+				if (this.connectTimeout > 0 || this.connectionRequestTimeout > 0 || this.socketTimeout > 0) {
 					config = RequestConfig.custom()
 							.setConnectTimeout(this.connectTimeout)
+							.setConnectionRequestTimeout(this.connectionRequestTimeout)
 							.setSocketTimeout(this.socketTimeout)
 							.build();
 				}

spring-web/src/main/java/org/springframework/remoting/httpinvoker/HttpComponentsHttpInvokerRequestExecutor.java

@@ -70,6 +70,7 @@ public class HttpComponentsHttpInvokerRequestExecutor extends AbstractHttpInvoke
 
 	private HttpClient httpClient;
 	private int connectionTimeout = 0;
+	private int connectionRequestTimeout = 0;
 	private int readTimeout = DEFAULT_READ_TIMEOUT_MILLISECONDS;
 
 
@@ -148,6 +149,16 @@ private void setLegacyConnectionTimeout(HttpClient client, int timeout) {
 		}
 	}
 
+	/**
+	 * Set the timeout in milliseconds used when requesting a connection from the connection
+	 * manager using the underlying HttpClient.
+	 * A timeout value of 0 specifies an infinite timeout.
+	 * @param connectionRequestTimeout the timeout value to request a connection in milliseconds
+	 */
+	public void setConnectionRequestTimeout(int connectionRequestTimeout) {
+		this.connectionRequestTimeout = connectionRequestTimeout;
+	}
+
 	/**
 	 * Set the socket read timeout for the underlying HttpClient.
 	 * A timeout value of 0 specifies an infinite timeout.
@@ -240,9 +251,10 @@ protected HttpPost createHttpPost(HttpInvokerClientConfiguration config) throws
 	 * @return the RequestConfig to use
 	 */
 	protected RequestConfig createRequestConfig(HttpInvokerClientConfiguration config) {
-		if (this.connectionTimeout > 0 || this.readTimeout > 0) {
+		if (this.connectionTimeout > 0 || this.connectionRequestTimeout > 0 || this.readTimeout > 0) {
 			return RequestConfig.custom()
 					.setConnectTimeout(this.connectionTimeout)
+					.setConnectionRequestTimeout(this.connectionRequestTimeout)
 					.setSocketTimeout(this.readTimeout)
 					.build();
 		}

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

@@ -63,6 +63,7 @@ public void assertCustomConfig() throws Exception {
 		HttpClient httpClient = HttpClientBuilder.create().build();
 		HttpComponentsClientHttpRequestFactory hrf = new HttpComponentsClientHttpRequestFactory(httpClient);
 		hrf.setConnectTimeout(1234);
+		hrf.setConnectionRequestTimeout(4321);
 		hrf.setReadTimeout(4567);
 
 		URI uri = new URI(baseUrl + "/status/ok");
@@ -75,6 +76,7 @@ public void assertCustomConfig() throws Exception {
 				RequestConfig.class.isInstance(config));
 		RequestConfig requestConfig = (RequestConfig) config;
 		assertEquals("Wrong custom connection timeout", 1234, requestConfig.getConnectTimeout());
+		assertEquals("Wrong custom connection request timeout", 4321, requestConfig.getConnectionRequestTimeout());
 		assertEquals("Wrong custom socket timeout", 4567, requestConfig.getSocketTimeout());
 	}
 

spring-web/src/test/java/org/springframework/remoting/httpinvoker/HttpComponentsHttpInvokerRequestExecutorTests.java

@@ -43,6 +43,16 @@ public void customizeConnectionTimeout() throws IOException {
 		assertEquals(5000, httpPost.getConfig().getConnectTimeout());
 	}
 
+	@Test
+	public void customizeConnectionRequestTimeout() throws IOException {
+		HttpComponentsHttpInvokerRequestExecutor executor = new HttpComponentsHttpInvokerRequestExecutor();
+		executor.setConnectionRequestTimeout(7000);
+
+		HttpInvokerClientConfiguration config = mockHttpInvokerClientConfiguration("http://fake-service");
+		HttpPost httpPost = executor.createHttpPost(config);
+		assertEquals(7000, httpPost.getConfig().getConnectionRequestTimeout());
+	}
+
 	@Test
 	public void customizeReadTimeout() throws IOException {
 		HttpComponentsHttpInvokerRequestExecutor executor = new HttpComponentsHttpInvokerRequestExecutor();