Fix deprecation warnings

* Use `MatcherAssert.assertThat()`
instead of deprecated `Assert.assertThat()`
* Use `IntegrationFlows.fromSupplier(Supplier)`
instead of removed `IntegrationFlows.from(Supplier)`
* Use `org.springframework.integration:spring-integration-test`
throughout the project for more testing utilities

basic/testing-examples/pom.xml

@@ -3,7 +3,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.springframework.integration.samples</groupId>
   <artifactId>testing-examples</artifactId>
-  <version>5.3.0.RELEASE</version>
+  <version>5.4.0</version>
   <name>Testing Examples</name>
   <description>Testing Examples</description>
   <url>https://projects.spring.io/spring-integration</url>
@@ -155,17 +155,6 @@
         </exclusion>
       </exclusions>
     </dependency>
-    <dependency>
-      <groupId>org.springframework</groupId>
-      <artifactId>spring-test</artifactId>
-      <scope>test</scope>
-      <exclusions>
-        <exclusion>
-          <artifactId>jackson-module-kotlin</artifactId>
-          <groupId>com.fasterxml.jackson.module</groupId>
-        </exclusion>
-      </exclusions>
-    </dependency>
     <dependency>
       <groupId>org.springframework.integration</groupId>
       <artifactId>spring-integration-test</artifactId>
@@ -202,14 +191,14 @@
       <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-framework-bom</artifactId>
-        <version>5.2.7.RELEASE</version>
+        <version>5.3.0-M1</version>
         <scope>import</scope>
         <type>pom</type>
       </dependency>
       <dependency>
         <groupId>org.springframework.integration</groupId>
         <artifactId>spring-integration-bom</artifactId>
-        <version>5.3.1.RELEASE</version>
+        <version>5.4.0-M1</version>
         <scope>import</scope>
         <type>pom</type>
       </dependency>

basic/testing-examples/src/test/java/org/springframework/integration/samples/testing/aggregator/CommaDelimitedAggregatorTests.java

@@ -15,10 +15,10 @@
  */
 package org.springframework.integration.samples.testing.aggregator;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertThat;
 import static org.springframework.integration.test.matcher.PayloadMatcher.hasPayload;
 
 import java.util.List;
@@ -36,15 +36,15 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 
 /**
- * 
+ *
  * Shows how to test a custom aggregator. Unit test for the class and
  * tests for the integration subflow.
  * The subflow has direct input and output channels. The flow would
  * be a fragment of a larger flow. Since the output channel is direct,
- * it has no subscribers outside the context of a larger flow. So, 
+ * it has no subscribers outside the context of a larger flow. So,
  * in this test case, we bridge it to a {@link QueueChannel} to
  * facilitate easy testing.
- * 
+ *
  * @author Gary Russell
  * @since 2.0.2
  *
@@ -52,10 +52,10 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 @ContextConfiguration	// default context name is <ClassName>-context.xml
 @RunWith(SpringJUnit4ClassRunner.class)
 public class CommaDelimitedAggregatorTests {
-	
+
 	@Autowired
 	MessageChannel inputChannel;
-	
+
 	@Autowired
 	QueueChannel testChannel;
 
@@ -65,7 +65,7 @@ public class CommaDelimitedAggregatorTests {
 		String out = new CommaDelimitedAggregator().aggregate(splits);
 		assertEquals("a,b,c", out);
 	}
-	
+
 	@Test
 	public void unitTestClass2() {
 		List<String> splits = new CommaDelimitedSplitter().split("   a    ,,    c ");

basic/testing-examples/src/test/java/org/springframework/integration/samples/testing/filter/PetFilterTests.java

@@ -15,10 +15,10 @@
  */
 package org.springframework.integration.samples.testing.filter;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.springframework.integration.test.matcher.PayloadMatcher.hasPayload;
 
@@ -34,30 +34,30 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 
 /**
- * 
- * Shows how to test a filter. 
+ *
+ * Shows how to test a filter.
  * The filter has direct input and output channels. The filter configuration would
  * be a fragment of a larger flow. Since the output channel is direct,
- * it has no subscribers outside the context of a larger flow. So, 
+ * it has no subscribers outside the context of a larger flow. So,
  * in this test case, we bridge it to a {@link QueueChannel} to
  * facilitate easy testing.
- * 
+ *
  * Similarly, we bridge the discard channel which is configured on the second
  * filter instance.
- * 
+ *
  * @author Gary Russell
  * @since 2.0.2
  */
 @ContextConfiguration	// default context name is <ClassName>-context.xml
 @RunWith(SpringJUnit4ClassRunner.class)
 public class PetFilterTests {
-	
+
 	@Autowired
 	MessageChannel inputChannel;
-	
+
 	@Autowired
 	MessageChannel inputChannel2;
-	
+
 	@Autowired
 	QueueChannel testChannel;
 
@@ -72,19 +72,19 @@ public class PetFilterTests {
 		String payload = "CAT:Fluffy";
 		assertFalse(new PetFilter().dogsOnly(payload));
 	}
-	
+
 	@Test
 	public void unitTestClassDog() {
 		String payload = "DOG:Fido";
 		assertTrue(new PetFilter().dogsOnly(payload));
 	}
-	
+
 	@Test
 	public void unitTestClassLizard() {
 		String payload = "LIZARD:Scaly";
 		assertFalse(new PetFilter().dogsOnly(payload));
 	}
-	
+
 	@Test
 	public void testCat() {
 		String payload = "CAT:Fluffy";
@@ -112,7 +112,7 @@ public class PetFilterTests {
 		Message<?> outMessage = testChannel.receive(0);
 		assertNull("Expected no output message", outMessage);
 	}
-	
+
 	@Test
 	public void testCatDiscard() {
 		String payload = "CAT:Fluffy";

basic/testing-examples/src/test/java/org/springframework/integration/samples/testing/gateway/GatewayTests.java

@@ -15,8 +15,8 @@
  */
 package org.springframework.integration.samples.testing.gateway;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertThat;
 import static org.springframework.integration.test.matcher.HeaderMatcher.hasHeader;
 import static org.springframework.integration.test.matcher.PayloadMatcher.hasPayload;
 
@@ -31,15 +31,15 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 
 /**
- * 
+ *
  * Shows how to test a gateway to ensure the message injected
  * into the Spring Integration flow is what we expected.
  * The gateway uses a direct input channel. The configuration would
  * be a fragment of a larger flow. Since the input channel is direct,
- * it has no subscribers outside the context of a larger flow. So, 
+ * it has no subscribers outside the context of a larger flow. So,
  * in this test case, we bridge it to a {@link QueueChannel} to
  * facilitate easy testing.
- * 
+ *
  * @author Gary Russell
  * @since 2.0.2
  *
@@ -47,13 +47,13 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 @ContextConfiguration	// default context name is <ClassName>-context.xml
 @RunWith(SpringJUnit4ClassRunner.class)
 public class GatewayTests {
-	
+
 	@Autowired
 	QueueChannel testChannel;
-	
+
 	@Autowired
 	VoidGateway gateway;
-	
+
 	@Test
 	public void testTrueHeader() {
 		String payload = "XXXABCXXX";

basic/testing-examples/src/test/java/org/springframework/integration/samples/testing/router/PetRouterTests.java

@@ -15,9 +15,9 @@
  */
 package org.springframework.integration.samples.testing.router;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertThat;
 import static org.springframework.integration.test.matcher.PayloadMatcher.hasPayload;
 
 import org.junit.Test;
@@ -32,51 +32,51 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 
 /**
- * 
+ *
  * Shows how to test a router; the router is configured to route to direct
  * channel names. The configuration would
  * be a fragment of a larger flow. Since the output channels are direct,
- * they have no subscribers outside the context of a larger flow. So, 
+ * they have no subscribers outside the context of a larger flow. So,
  * in this test case, we bridge them to {@link QueueChannel}s to
  * facilitate easy testing.
- * 
+ *
  * @author Gary Russell
  * @since 2.0.2
  */
 @ContextConfiguration	// default context name is <ClassName>-context.xml
 @RunWith(SpringJUnit4ClassRunner.class)
 public class PetRouterTests {
-	
+
 	@Autowired
 	MessageChannel inputChannel;
-	
+
 	@Autowired
 	QueueChannel testFelineChannel;
-	
+
 	@Autowired
 	QueueChannel testCanineChannel;
-	
+
 	@Autowired
 	QueueChannel testUnknownPetTypeChannel;
-	
+
 	@Test
 	public void unitTestClassCat() {
 		String payload = "CAT:Fluffy";
 		assertEquals("felineChannel", new PetRouter().route(payload));
 	}
-	
+
 	@Test
 	public void unitTestClassDog() {
 		String payload = "DOG:Fido";
 		assertEquals("canineChannel", new PetRouter().route(payload));
 	}
-	
+
 	@Test
 	public void unitTestClassLizard() {
 		String payload = "LIZARD:Scaly";
 		assertEquals("unknownPetTypeChannel", new PetRouter().route(payload));
 	}
-	
+
 	@Test
 	public void testCat() {
 		String payload = "CAT:Fluffy";

basic/testing-examples/src/test/java/org/springframework/integration/samples/testing/splitter/CommaDelimitedSplitterTests.java

@@ -15,10 +15,10 @@
  */
 package org.springframework.integration.samples.testing.splitter;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertThat;
 import static org.springframework.integration.test.matcher.PayloadMatcher.hasPayload;
 
 import java.util.List;
@@ -35,15 +35,15 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 
 /**
- * 
+ *
  * Shows how to test a custom splitter. Unit test for the class and
  * tests for the integration subflow.
  * The splitter has direct input and output channels. The splitter would
  * be a fragment of a larger flow. Since the output channel is direct,
- * it has no subscribers outside the context of a larger flow. So, 
+ * it has no subscribers outside the context of a larger flow. So,
  * in this test case, we bridge it to a {@link QueueChannel} to
  * facilitate easy testing.
- * 
+ *
  * @author Gary Russell
  * @since 2.0.2
  *
@@ -51,10 +51,10 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 @ContextConfiguration	// default context name is <ClassName>-context.xml
 @RunWith(SpringJUnit4ClassRunner.class)
 public class CommaDelimitedSplitterTests {
-	
+
 	@Autowired
 	MessageChannel inputChannel;
-	
+
 	@Autowired
 	QueueChannel testChannel;
 
@@ -66,7 +66,7 @@ public class CommaDelimitedSplitterTests {
 		assertEquals("b", splits.get(1));
 		assertEquals("c", splits.get(2));
 	}
-	
+
 	@Test
 	public void unitTestClass2() {
 		List<String> splits = new CommaDelimitedSplitter().split("   a    ,,    c ");