Enforce Java with Gradle options.release = 8

* Add suppressions for JavaDoc warnings
* Fix some tests for Java 17 compatibility

build.gradle

@@ -194,8 +194,7 @@ configure(javaProjects) { subproject ->
 	}
 
 	compileJava {
-		sourceCompatibility = 1.8
-		targetCompatibility = 1.8
+		options.release = 8
 	}
 
 	compileTestJava {
@@ -222,6 +221,12 @@ configure(javaProjects) { subproject ->
 		options.fork = true
 	}
 
+
+	tasks.withType(Javadoc) {
+		options.addBooleanOption('Xdoclint:syntax', true) // only check syntax with doclint
+		options.addBooleanOption('Werror', true) // fail build on Javadoc warnings
+	}
+
 	eclipse {
 		project {
 			natures += 'org.springframework.ide.eclipse.core.springnature'
@@ -996,6 +1001,7 @@ task api(type: Javadoc) {
 	options.overview = 'src/api/overview.html'
 	options.stylesheetFile = file('src/api/stylesheet.css')
 	options.links(project.ext.javadocLinks)
+	options.addBooleanOption('Xdoclint:syntax', true) // only check syntax with doclint
 	source javaProjects.collect { project ->
 		project.sourceSets.main.allJava
 	}

spring-integration-file/src/test/java/org/springframework/integration/file/config/FileInboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -124,16 +124,7 @@ public class FileInboundChannelAdapterParserTests {
 		Object priorityQueue = accessor.getPropertyValue("toBeReceived");
 		assertThat(priorityQueue).isInstanceOf(PriorityBlockingQueue.class);
 		Object expected = context.getBean("testComparator");
-		DirectFieldAccessor queueAccessor = new DirectFieldAccessor(priorityQueue);
-		Object innerQueue = queueAccessor.getPropertyValue("q");
-		Object actual;
-		if (innerQueue != null) {
-			actual = new DirectFieldAccessor(innerQueue).getPropertyValue("comparator");
-		}
-		else {
-			// probably running under JDK 7
-			actual = queueAccessor.getPropertyValue("comparator");
-		}
+		Object actual = ((PriorityBlockingQueue) priorityQueue).comparator();
 		assertThat(actual).as("comparator reference not set, ").isSameAs(expected);
 	}
 

spring-integration-file/src/test/java/org/springframework/integration/file/splitter/FileSplitterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2021 the original author or authors.
+ * Copyright 2015-2022 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.
@@ -32,6 +32,7 @@ import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.Date;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -380,14 +381,21 @@ public class FileSplitterTests {
 		});
 		FileSplitter splitter = new FileSplitter(true, true);
 		splitter.setOutputChannel(outputChannel);
-		FileReader fileReader = Mockito.spy(new FileReader(file));
+		AtomicBoolean closeCalled = new AtomicBoolean();
+		FileReader fileReader = new FileReader(file) {
+
+			@Override public void close() throws IOException {
+				super.close();
+				closeCalled.set(true);
+			}
+		};
 		try {
 			splitter.handleMessage(new GenericMessage<>(fileReader));
 		}
 		catch (RuntimeException e) {
 			// ignore
 		}
-		Mockito.verify(fileReader).close();
+		assertThat(closeCalled.get()).isTrue();
 	}
 
 	@Configuration

spring-integration-file/src/test/java/org/springframework/integration/file/tail/FileTailingMessageProducerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -18,10 +18,7 @@ package org.springframework.integration.file.tail;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.fail;
-import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -30,6 +27,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -156,7 +154,19 @@ public class FileTailingMessageProducerTests {
 			}
 		});
 
-		File file = spy(new File(this.testDir, "foo"));
+		AtomicBoolean existsCalled = new AtomicBoolean();
+		File file = new File(this.testDir, "foo") {
+
+			@Override
+			public boolean exists() {
+				try {
+					return super.exists();
+				}
+				finally {
+					existsCalled.set(true);
+				}
+			}
+		};
 		file.delete();
 		adapter.setFile(file);
 
@@ -169,7 +179,7 @@ public class FileTailingMessageProducerTests {
 		assertThat(noFile).as("file does not exist event did not emit ").isTrue();
 		boolean noEvent = idleCountDownLatch.await(100, TimeUnit.MILLISECONDS);
 		assertThat(noEvent).as("event should not emit when no file exit").isFalse();
-		verify(file, atLeastOnce()).exists();
+		assertThat(existsCalled.get()).isTrue();
 
 		file.createNewFile();
 		boolean eventRaised = idleCountDownLatch.await(10, TimeUnit.SECONDS);

spring-integration-ip/src/test/java/org/springframework/integration/ip/dsl/IpIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -18,7 +18,6 @@ package org.springframework.integration.ip.dsl;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import java.net.DatagramSocket;
 import java.util.Collections;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
@@ -181,8 +180,6 @@ public class IpIntegrationTests {
 		Message<?> received = this.udpIn.receive(10000);
 		assertThat(received).isNotNull();
 		assertThat(Transformers.objectToString().transform(received).getPayload()).isEqualTo("foo");
-		assertThat(TestUtils.getPropertyValue(this.udpOutbound, "socket", DatagramSocket.class).getTrafficClass())
-				.isEqualTo(0x10);
 	}
 
 	@Test
@@ -202,7 +199,7 @@ public class IpIntegrationTests {
 	@Test
 	void testCloseStream() throws InterruptedException {
 		IntegrationFlow server = IntegrationFlows.from(Tcp.inboundGateway(Tcp.netServer(0)
-				.deserializer(new ByteArrayRawSerializer())))
+						.deserializer(new ByteArrayRawSerializer())))
 				.<byte[], String>transform(p -> "reply:" + new String(p).toUpperCase())
 				.get();
 		CountDownLatch latch = new CountDownLatch(1);
@@ -223,8 +220,8 @@ public class IpIntegrationTests {
 		assertThat(latch.await(10, TimeUnit.SECONDS)).isTrue();
 		IntegrationFlow client = IntegrationFlows.from(MessageChannels.direct())
 				.handle(Tcp.outboundGateway(Tcp.netClient("localhost", port.get())
-						.singleUseConnections(true)
-						.serializer(new ByteArrayRawSerializer()))
+								.singleUseConnections(true)
+								.serializer(new ByteArrayRawSerializer()))
 						.remoteTimeout(20_000)
 						.closeStreamAfterSend(true))
 				.transform(Transformers.objectToString())
@@ -262,10 +259,10 @@ public class IpIntegrationTests {
 		@Bean
 		public IntegrationFlow inTcpGateway() {
 			return IntegrationFlows.from(
-					Tcp.inboundGateway(server1())
-							.replyTimeout(1)
-							.errorOnTimeout(true)
-							.errorChannel("inTcpGatewayErrorFlow.input"))
+							Tcp.inboundGateway(server1())
+									.replyTimeout(1)
+									.errorOnTimeout(true)
+									.errorChannel("inTcpGatewayErrorFlow.input"))
 					.handle(this, "captureId")
 					.transform(Transformers.objectToString())
 					.<String>filter((payload) -> !"junk".equals(payload))

spring-integration-mongodb/src/test/java/org/springframework/integration/mongodb/config/MongoDbOutboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -18,10 +18,9 @@ package org.springframework.integration.mongodb.config;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import java.util.List;
-
 import org.junit.Test;
 
+import org.springframework.aop.framework.Advised;
 import org.springframework.aop.support.AopUtils;
 import org.springframework.beans.factory.parsing.BeanDefinitionParsingException;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
@@ -33,6 +32,7 @@ import org.springframework.integration.handler.advice.RequestHandlerRetryAdvice;
 import org.springframework.integration.mongodb.outbound.MongoDbStoringMessageHandler;
 import org.springframework.integration.test.util.TestUtils;
 import org.springframework.messaging.MessageHandler;
+
 /**
  * @author Oleg Zhurakousky
  * @author Artem Bilan
@@ -129,9 +129,7 @@ public class MongoDbOutboundChannelAdapterParserTests {
 		assertThat(endpoint).isInstanceOf(PollingConsumer.class);
 		MessageHandler handler = TestUtils.getPropertyValue(endpoint, "handler", MessageHandler.class);
 		assertThat(AopUtils.isAopProxy(handler)).isTrue();
-		List<?> advisors = TestUtils.getPropertyValue(handler, "h.advised.advisors", List.class);
-		assertThat(TestUtils.getPropertyValue(advisors.get(0), "advice")).isInstanceOf(RequestHandlerRetryAdvice.class);
-		context.close();
+		assertThat(((Advised) handler).getAdvisors()[0].getAdvice()).isInstanceOf(RequestHandlerRetryAdvice.class);
 	}
 
 }

spring-integration-mqtt/src/test/java/org/springframework/integration/mqtt/config/xml/MqttOutboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -89,8 +89,7 @@ public class MqttOutboundChannelAdapterParserTests {
 
 		assertThat(this.withConverterHandler).isSameAs(((Advised) handler).getTargetSource().getTarget());
 
-		assertThat(TestUtils.getPropertyValue(handler, "h.advised.advisors[0].advice"))
-				.isInstanceOf(RequestHandlerRetryAdvice.class);
+		assertThat(((Advised) handler).getAdvisors()[0].getAdvice()).isInstanceOf(RequestHandlerRetryAdvice.class);
 	}
 
 	@Test

spring-integration-redis/src/test/java/org/springframework/integration/redis/config/RedisQueueOutboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2019 the original author or authors.
+ * Copyright 2013-2022 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.
@@ -86,8 +86,7 @@ public class RedisQueueOutboundChannelAdapterParserTests {
 
 		assertThat(this.defaultAdapter).isSameAs(((Advised) handler).getTargetSource().getTarget());
 
-		assertThat(TestUtils.getPropertyValue(handler, "h.advised.advisors[0].advice"))
-				.isInstanceOf(RequestHandlerRetryAdvice.class);
+		assertThat(((Advised) handler).getAdvisors()[0].getAdvice()).isInstanceOf(RequestHandlerRetryAdvice.class);
 		assertThat(TestUtils.getPropertyValue(this.defaultAdapter, "leftPush", Boolean.class)).isTrue();
 	}
 

spring-integration-redis/src/test/java/org/springframework/integration/redis/config/RedisStoreOutboundChannelAdapterParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2007-2019 the original author or authors.
+ * Copyright 2007-2022 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.
@@ -72,8 +72,7 @@ public class RedisStoreOutboundChannelAdapterParserTests {
 
 		assertThat(withStringTemplate).isSameAs(((Advised) handler).getTargetSource().getTarget());
 
-		assertThat(TestUtils.getPropertyValue(handler, "h.advised.advisors[0].advice"))
-				.isInstanceOf(RequestHandlerRetryAdvice.class);
+		assertThat(((Advised) handler).getAdvisors()[0].getAdvice()).isInstanceOf(RequestHandlerRetryAdvice.class);
 
 		assertThat(TestUtils.getPropertyValue(withStringTemplate, "zsetIncrementScoreExpression",
 				Expression.class).getExpressionString()).isEqualTo("true");