GH-3677: Doc for URL conn customization in FeedCA (#3678)

* GH-3677: Doc for URL conn customization in FeedCA

Fixes https://github.com/spring-projects/spring-integration/issues/3677

If there is need to have a `URLConnection` customized, the `UrlResource`
has to be used instead of plain `URL` injection into the `FeedEntryMessageSource`

* * Add a sample to docs for connection customization

spring-integration-feed/src/test/java/org/springframework/integration/feed/inbound/FeedEntryMessageSourceTests.java

@@ -17,16 +17,20 @@
 package org.springframework.integration.feed.inbound;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.mockito.Mockito.mock;
 
 import java.io.File;
+import java.io.IOException;
+import java.net.HttpURLConnection;
 import java.net.URL;
 
-import org.junit.Before;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.UrlResource;
 import org.springframework.integration.metadata.PropertiesPersistingMetadataStore;
 import org.springframework.messaging.Message;
 
@@ -43,7 +47,7 @@ import com.rometools.rome.feed.synd.SyndEntry;
  */
 public class FeedEntryMessageSourceTests {
 
-	@Before
+	@BeforeEach
 	public void prepare() {
 		File metadataStoreFile = new File(System.getProperty("java.io.tmpdir") + "/spring-integration/",
 				"metadata-store.properties");
@@ -52,17 +56,28 @@ public class FeedEntryMessageSourceTests {
 		}
 	}
 
-	@Test(expected = IllegalArgumentException.class)
+	@Test
 	public void testFailureWhenNotInitialized() throws Exception {
 		URL url = new ClassPathResource("org/springframework/integration/feed/sample.rss").getURL();
 		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(url, "foo");
-		feedEntrySource.receive();
+		assertThatExceptionOfType(IllegalArgumentException.class)
+				.isThrownBy(feedEntrySource::receive);
 	}
 
 	@Test
 	public void testReceiveFeedWithNoEntries() throws Exception {
 		URL url = new ClassPathResource("org/springframework/integration/feed/empty.rss").getURL();
-		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(url, "foo");
+		UrlResource urlResource =
+				new UrlResource(url) {
+
+					@Override
+					protected void customizeConnection(HttpURLConnection connection) throws IOException {
+						super.customizeConnection(connection);
+						connection.setConnectTimeout(10000);
+						connection.setReadTimeout(5000);
+					}
+				};
+		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(urlResource, "foo");
 		feedEntrySource.setBeanName("feedReader");
 		feedEntrySource.setBeanFactory(mock(BeanFactory.class));
 		feedEntrySource.afterPropertiesSet();
@@ -70,7 +85,7 @@ public class FeedEntryMessageSourceTests {
 	}
 
 	@Test
-	public void testReceiveFeedWithEntriesSorted() throws Exception {
+	public void testReceiveFeedWithEntriesSorted() {
 		ClassPathResource resource = new ClassPathResource("org/springframework/integration/feed/sample.rss");
 		FeedEntryMessageSource source = new FeedEntryMessageSource(resource, "foo");
 		source.setBeanName("feedReader");
@@ -90,7 +105,7 @@ public class FeedEntryMessageSourceTests {
 	// verifies that when entry has been updated since publish, that is taken into
 	// account when determining if the feed entry has been seen before
 	@Test
-	public void testEntryHavingBeenUpdatedAfterPublishAndRepeat() throws Exception {
+	public void testEntryHavingBeenUpdatedAfterPublishAndRepeat() {
 		ClassPathResource resource = new ClassPathResource("org/springframework/integration/feed/atom.xml");
 		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(resource, "foo");
 		feedEntrySource.setBeanName("feedReader");
@@ -124,7 +139,7 @@ public class FeedEntryMessageSourceTests {
 	// will test that last feed entry is remembered between the sessions
 	// and no duplicate entries are retrieved
 	@Test
-	public void testReceiveFeedWithRealEntriesAndRepeatWithPersistentMetadataStore() throws Exception {
+	public void testReceiveFeedWithRealEntriesAndRepeatWithPersistentMetadataStore() {
 		ClassPathResource resource = new ClassPathResource("org/springframework/integration/feed/sample.rss");
 		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(resource, "foo");
 		feedEntrySource.setBeanName("feedReader");
@@ -166,7 +181,7 @@ public class FeedEntryMessageSourceTests {
 	// will test that last feed entry is NOT remembered between the sessions, since
 	// no persistent MetadataStore is provided and the same entries are retrieved again
 	@Test
-	public void testReceiveFeedWithRealEntriesAndRepeatNoPersistentMetadataStore() throws Exception {
+	public void testReceiveFeedWithRealEntriesAndRepeatNoPersistentMetadataStore() {
 		ClassPathResource resource = new ClassPathResource("org/springframework/integration/feed/sample.rss");
 		FeedEntryMessageSource feedEntrySource = new FeedEntryMessageSource(resource, "foo");
 		feedEntrySource.setBeanName("feedReader");

src/reference/asciidoc/feed.adoc

@@ -7,8 +7,8 @@ The implementation is based on the https://rometools.github.io/rome/[ROME Framew
 You need to include this dependency into your project:
 
 ====
+[source, xml, subs="normal", role="primary"]
 .Maven
-[source, xml, subs="normal"]
 ----
 <dependency>
     <groupId>org.springframework.integration</groupId>
@@ -17,8 +17,8 @@ You need to include this dependency into your project:
 </dependency>
 ----
 
+[source, groovy, subs="normal", role="secondary"]
 .Gradle
-[source, groovy, subs="normal"]
 ----
 compile "org.springframework.integration:spring-integration-feed:{project-version}"
 ----
@@ -87,6 +87,31 @@ This is useful when the feed source is not an HTTP endpoint but is any other res
 In the `FeedEntryMessageSource` logic, such a resource (or provided `URL`) is parsed by the `SyndFeedInput` to the `SyndFeed` object for the processing mentioned earlier.
 You can also inject a customized `SyndFeedInput` (for example, with the `allowDoctypes` option) instance into the `FeedEntryMessageSource`.
 
+[NOTE]
+====
+If the connection to the feed needs some customization, e.g. connection and read timeouts, the `org.springframework.core.io.UrlResource` extension with its `customizeConnection(HttpURLConnection)` override has to be used instead of plain `URL` injection into the `FeedEntryMessageSource`.
+For example:
+
+[source, java]
+----
+@Bean
+@InboundChannelAdapter("feedChannel")
+FeedEntryMessageSource feedEntrySource() {
+    UrlResource urlResource =
+	    new UrlResource(url) {
+
+	        @Override
+	        protected void customizeConnection(HttpURLConnection connection) throws IOException {
+	            super.customizeConnection(connection);
+	            connection.setConnectTimeout(10000);
+	            connection.setReadTimeout(5000);
+	        }
+	    };
+    return new FeedEntryMessageSource(urlResource, "myKey");
+}
+----
+====
+
 [[feed-java-configuration]]
 === Java DSL Configuration
 
@@ -126,4 +151,4 @@ public class FeedJavaApplication {
 
 }
 ----
-====
+====