Remove SocketUtils usage

* Remove usage of non-stable `org.springframework.util.SocketUtils`
* Replace it with `0` for those tests where it is possible to select OS port
* Remove the mentioning of the `SocketUtils` from the `testing.adoc`
* Use `TransportConstants.DEFAULT_STOMP_PORT` for `StompServerIntegrationTests`.
We may disable this test in the future for CI if it is not going to be stable
* Introduce `Supplier<String> connectUrl` variants for `ZeroMqMessageHandler`
to let it defer connection evaluation until subscription to the socket `Mono`
in the `ZeroMqMessageHandler`.
* Move connection logic in the `ZeroMqMessageHandler` to `Lifecycle.start()`

Related to spring-projects/spring-framework#28054

**Cherry-pick to `5.5.x`**

# Conflicts:
#	spring-integration-stomp/src/test/java/org/springframework/integration/stomp/client/StompServerIntegrationTests.java

spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/MulticastRule.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2020 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.
@@ -29,7 +29,6 @@
 import org.springframework.integration.ip.util.SocketTestUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
-import org.springframework.util.SocketUtils;
 
 /**
  * @author Artem Bilan
@@ -76,7 +75,7 @@ private NetworkInterface checkMulticast() throws Exception {
 		}
 		try {
 			MulticastSocket socket = new MulticastSocket();
-			socket.joinGroup(new InetSocketAddress(this.group, SocketUtils.findAvailableUdpPort()), nic);
+			socket.joinGroup(new InetSocketAddress(this.group, 0), nic);
 			socket.close();
 		}
 		catch (Exception e) {

spring-integration-ip/src/test/java/org/springframework/integration/ip/udp/UdpChannelAdapterTests.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.
@@ -50,7 +50,6 @@
 import org.springframework.integration.test.rule.Log4j2LevelAdjuster;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.SubscribableChannel;
-import org.springframework.util.SocketUtils;
 
 /**
  *
@@ -284,8 +283,7 @@ public void testMulticastReceiver() throws Exception {
 			}
 
 		}
-		DatagramSocket datagramSocket =
-				new DatagramSocket(SocketUtils.findAvailableUdpPort(), inetAddress);
+		DatagramSocket datagramSocket = new DatagramSocket(0, inetAddress);
 		datagramSocket.send(packet);
 		datagramSocket.close();
 

spring-integration-stomp/src/test/java/org/springframework/integration/stomp/client/StompServerIntegrationTests.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.
@@ -54,7 +54,6 @@
 import org.springframework.messaging.simp.stomp.StompCommand;
 import org.springframework.messaging.support.GenericMessage;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
-import org.springframework.util.SocketUtils;
 
 /**
  * @author Artem Bilan
@@ -70,17 +69,16 @@ public class StompServerIntegrationTests {
 
 	@BeforeAll
 	public static void setup() throws Exception {
-		int port = SocketUtils.findAvailableTcpPort(61613);
 		activeMQBroker = new BrokerService();
-		activeMQBroker.addConnector("stomp://127.0.0.1:" + port);
+		activeMQBroker.addConnector("stomp://127.0.0.1:" + BrokerService.DEFAULT_PORT);
 		activeMQBroker.setPersistent(false);
 		activeMQBroker.setUseJmx(false);
 		activeMQBroker.setEnableStatistics(false);
 		activeMQBroker.getSystemUsage().getMemoryUsage().setLimit(1024 * 1024 * 5);
 		activeMQBroker.getSystemUsage().getTempUsage().setLimit(1024 * 1024 * 5);
 		activeMQBroker.start();
 
-		stompClient = new ReactorNettyTcpStompClient("127.0.0.1", port);
+		stompClient = new ReactorNettyTcpStompClient("127.0.0.1", Integer.parseInt(BrokerService.DEFAULT_PORT));
 		stompClient.setMessageConverter(new PassThruMessageConverter());
 		ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler();
 		taskScheduler.afterPropertiesSet();

spring-integration-syslog/src/test/java/org/springframework/integration/syslog/config/SyslogReceivingChannelAdapterParserTests-context.xml

@@ -9,9 +9,7 @@
 		http://www.springframework.org/schema/integration https://www.springframework.org/schema/integration/spring-integration.xsd
 		http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd">
 
-	<bean id="socketUtils" class="org.springframework.util.SocketUtils" />
-
-	<int-syslog:inbound-channel-adapter id="foo" port="#{socketUtils.findAvailableUdpPort(1514)}" />
+	<int-syslog:inbound-channel-adapter id="foo" port="0" />
 
 	<int-syslog:inbound-channel-adapter id="foobar" channel="foo" port="1514" auto-startup="false" />
 
@@ -42,7 +40,7 @@
 	<bean id="converter"
 		class="org.springframework.integration.syslog.config.SyslogReceivingChannelAdapterParserTests$PassThruConverter" />
 
-	<int-syslog:inbound-channel-adapter id="bar" protocol="tcp" port="#{socketUtils.findAvailableTcpPort(1514)}" />
+	<int-syslog:inbound-channel-adapter id="bar" protocol="tcp" port="0" />
 
 	<int:channel id="bar">
 		<int:queue/>

spring-integration-syslog/src/test/java/org/springframework/integration/syslog/config/SyslogReceivingChannelAdapterParserTests.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.
@@ -17,17 +17,18 @@
 package org.springframework.integration.syslog.config;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.fail;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
+import java.lang.reflect.Method;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetSocketAddress;
 import java.net.Socket;
+import java.nio.charset.StandardCharsets;
 
 import javax.net.SocketFactory;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -42,19 +43,21 @@
 import org.springframework.integration.test.util.TestUtils;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.PollableChannel;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+import org.springframework.util.ReflectionUtils;
 
 /**
  * @author Gary Russell
+ * @author Artem Bilan
+ *
  * @since 3.0
  *
  */
-@ContextConfiguration
-@RunWith(SpringJUnit4ClassRunner.class)
+@SpringJUnitConfig
 public class SyslogReceivingChannelAdapterParserTests {
 
-	@Autowired @Qualifier("foo.adapter")
+	@Autowired
+	@Qualifier("foo.adapter")
 	private UdpSyslogReceivingChannelAdapter adapter1;
 
 	@Autowired
@@ -63,7 +66,8 @@ public class SyslogReceivingChannelAdapterParserTests {
 	@Autowired
 	private PollableChannel foo;
 
-	@Autowired @Qualifier("explicitUdp.adapter")
+	@Autowired
+	@Qualifier("explicitUdp.adapter")
 	private UdpSyslogReceivingChannelAdapter explicitUdpAdapter;
 
 	@Autowired
@@ -81,7 +85,8 @@ public class SyslogReceivingChannelAdapterParserTests {
 	@Autowired
 	private RFC5424MessageConverter rfc5424;
 
-	@Autowired @Qualifier("bar.adapter")
+	@Autowired
+	@Qualifier("bar.adapter")
 	private TcpSyslogReceivingChannelAdapter adapter2;
 
 	@Autowired
@@ -95,8 +100,10 @@ public class SyslogReceivingChannelAdapterParserTests {
 
 	@Test
 	public void testSimplestUdp() throws Exception {
-		int port = TestUtils.getPropertyValue(adapter1, "udpAdapter.port", Integer.class);
-		byte[] buf = "<157>JUL 26 22:08:35 WEBERN TESTING[70729]: TEST SYSLOG MESSAGE".getBytes("UTF-8");
+		Method getPort = ReflectionUtils.findMethod(UdpSyslogReceivingChannelAdapter.class, "getPort");
+		ReflectionUtils.makeAccessible(getPort);
+		int port = (int) ReflectionUtils.invokeMethod(getPort, this.adapter1);
+		byte[] buf = "<157>JUL 26 22:08:35 WEBERN TESTING[70729]: TEST SYSLOG MESSAGE".getBytes(StandardCharsets.UTF_8);
 		DatagramPacket packet = new DatagramPacket(buf, buf.length, new InetSocketAddress("localhost", port));
 		DatagramSocket socket = new DatagramSocket();
 		Thread.sleep(1000);
@@ -108,13 +115,13 @@ public void testSimplestUdp() throws Exception {
 	}
 
 	@Test
-	public void testExplicitChannelUdp() throws Exception {
+	public void testExplicitChannelUdp() {
 		assertThat(TestUtils.getPropertyValue(foobar, "udpAdapter.port")).isEqualTo(1514);
 		assertThat(TestUtils.getPropertyValue(foobar, "outputChannel")).isSameAs(foo);
 	}
 
 	@Test
-	public void testExplicitUdp() throws Exception {
+	public void testExplicitUdp() {
 		assertThat(TestUtils.getPropertyValue(explicitUdpAdapter, "outputChannel")).isSameAs(explicitUdp);
 	}
 
@@ -133,9 +140,9 @@ public void testFullBoatUdp() {
 	public void testSimplestTcp() throws Exception {
 		AbstractServerConnectionFactory connectionFactory = TestUtils.getPropertyValue(adapter2, "connectionFactory",
 				AbstractServerConnectionFactory.class);
-		int port = connectionFactory.getPort();
 		waitListening(connectionFactory, 10000L);
-		byte[] buf = "<157>JUL 26 22:08:35 WEBERN TESTING[70729]: TEST SYSLOG MESSAGE\n".getBytes("UTF-8");
+		byte[] buf = "<157>JUL 26 22:08:35 WEBERN TESTING[70729]: TEST SYSLOG MESSAGE\n".getBytes(StandardCharsets.UTF_8);
+		int port = connectionFactory.getPort();
 		Socket socket = SocketFactory.getDefault().createSocket("localhost", port);
 		Thread.sleep(1000);
 		socket.getOutputStream().write(buf);
@@ -159,57 +166,40 @@ public void testFullBoatTcp() {
 
 	@Test
 	public void testPortOnUdpChild() {
-		try {
-			new ClassPathXmlApplicationContext(this.getClass().getSimpleName() + "-fail1-context.xml", this.getClass())
-					.close();
-			fail("Expected exception");
-		}
-		catch (BeanDefinitionParsingException e) {
-			assertThat(e.getMessage().startsWith(
-					"Configuration problem: When child element 'udp-attributes' is present, 'port' must be defined " +
-							"there"))
-					.isTrue();
-		}
+		assertThatExceptionOfType(BeanDefinitionParsingException.class)
+				.isThrownBy(() ->
+						new ClassPathXmlApplicationContext(getClass().getSimpleName() + "-fail1-context.xml",
+								getClass()))
+				.withMessageStartingWith(
+						"Configuration problem: " +
+								"When child element 'udp-attributes' is present, 'port' must be defined there");
 	}
 
 	@Test
 	public void testPortWithTCPFactory() {
-		try {
-			new ClassPathXmlApplicationContext(this.getClass().getSimpleName() + "-fail2-context.xml", this.getClass())
-					.close();
-			fail("Expected exception");
-		}
-		catch (BeanCreationException e) {
-			assertThat(e.getCause().getMessage()).isEqualTo("Cannot specify both 'port' and 'connectionFactory'");
-		}
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(() ->
+						new ClassPathXmlApplicationContext(getClass().getSimpleName() + "-fail2-context.xml",
+								getClass()))
+				.withStackTraceContaining("Cannot specify both 'port' and 'connectionFactory'");
 	}
 
 	@Test
 	public void testUdpChildWithTcp() {
-		try {
-			new ClassPathXmlApplicationContext(this.getClass().getSimpleName() + "-fail3-context.xml", this.getClass())
-					.close();
-			fail("Expected exception");
-		}
-		catch (BeanCreationException e) {
-			e.printStackTrace();
-
-			assertThat(e.getCause().getMessage())
-					.isEqualTo("Cannot specify 'udp-attributes' when the protocol is 'tcp'");
-		}
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(() ->
+						new ClassPathXmlApplicationContext(getClass().getSimpleName() + "-fail3-context.xml",
+								getClass()))
+				.withStackTraceContaining("Cannot specify 'udp-attributes' when the protocol is 'tcp'");
 	}
 
 	@Test
 	public void testUDPWithTCPFactory() {
-		try {
-			new ClassPathXmlApplicationContext(this.getClass().getSimpleName() + "-fail4-context.xml", this.getClass())
-					.close();
-			fail("Expected exception");
-		}
-		catch (BeanCreationException e) {
-			assertThat(e.getCause().getMessage())
-					.isEqualTo("Cannot specify 'connection-factory' unless the protocol is 'tcp'");
-		}
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(() ->
+						new ClassPathXmlApplicationContext(this.getClass().getSimpleName() + "-fail4-context.xml",
+								getClass()))
+				.withStackTraceContaining("Cannot specify 'connection-factory' unless the protocol is 'tcp'");
 	}
 
 	public static class PassThruConverter implements MessageConverter {
@@ -229,7 +219,7 @@ public Message<?> fromSyslog(Message<?> syslog) {
 	 * @throws IllegalStateException
 	 */
 	private void waitListening(AbstractServerConnectionFactory serverConnectionFactory, Long delay)
-		throws IllegalStateException {
+			throws IllegalStateException {
 		if (delay == null) {
 			delay = 100L;
 		}

spring-integration-zeromq/src/main/java/org/springframework/integration/zeromq/ZeroMqProxy.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2021 the original author or authors.
+ * Copyright 2020-2022 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.
@@ -212,7 +212,7 @@ public int getBackendPort() {
 
 	/**
 	 * Return the address an {@code inproc} control socket is bound or null if this proxy has not been started yet.
-	 * @return the the address for control socket or null
+	 * @return the address for control socket or null
 	 */
 	@Nullable
 	public String getControlAddress() {
@@ -222,7 +222,7 @@ public String getControlAddress() {
 	/**
 	 * Return the address an {@code inproc} capture socket is bound or null if this proxy has not been started yet
 	 * or {@link #captureAddress} is false.
-	 * @return the the address for capture socket or null
+	 * @return the address for capture socket or null
 	 */
 	@Nullable
 	public String getCaptureAddress() {

spring-integration-zeromq/src/main/java/org/springframework/integration/zeromq/dsl/ZeroMq.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2020 the original author or authors.
+ * Copyright 2020-2022 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.integration.zeromq.dsl;
 
+import java.util.function.Supplier;
+
 import org.zeromq.SocketType;
 import org.zeromq.ZContext;
 
@@ -53,6 +55,18 @@ public static ZeroMqChannelSpec pubSubZeroMqChannel(ZContext context) {
 	 * @return the spec.
 	 */
 	public static ZeroMqMessageHandlerSpec outboundChannelAdapter(ZContext context, String connectUrl) {
+		return outboundChannelAdapter(context, () -> connectUrl);
+	}
+
+	/**
+	 * Create an instance of {@link ZeroMqMessageHandlerSpec} for the provided {@link ZContext}
+	 * and connection URL supplier.
+	 * @param context the {@link ZContext} to use.
+	 * @param connectUrl the supplier for URL to connect a ZeroMq socket to.
+	 * @return the spec.
+	 * @since 5.5.9
+	 */
+	public static ZeroMqMessageHandlerSpec outboundChannelAdapter(ZContext context, Supplier<String> connectUrl) {
 		return new ZeroMqMessageHandlerSpec(context, connectUrl);
 	}
 
@@ -70,6 +84,21 @@ public static ZeroMqMessageHandlerSpec outboundChannelAdapter(ZContext context,
 		return new ZeroMqMessageHandlerSpec(context, connectUrl, socketType);
 	}
 
+	/**
+	 * Create an instance of {@link ZeroMqMessageHandlerSpec} for the provided {@link ZContext},
+	 * connection URL supplier and {@link SocketType}.
+	 * @param context the {@link ZContext} to use.
+	 * @param connectUrl the supplier for URL to connect a ZeroMq socket to.
+	 * @param socketType the {@link SocketType} for ZeroMq socket.
+	 * @return the spec.
+	 * @since 5.5.9
+	 */
+	public static ZeroMqMessageHandlerSpec outboundChannelAdapter(ZContext context, Supplier<String> connectUrl,
+			SocketType socketType) {
+
+		return new ZeroMqMessageHandlerSpec(context, connectUrl, socketType);
+	}
+
 	/**
 	 * Create an instance of {@link ZeroMqMessageProducerSpec} for the provided {@link ZContext}.
 	 * @param context the {@link ZContext} to use.