Remove usage of SocketUtils in tests

Closes gh-29821

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/rsocket/netty/NettyRSocketServerFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -51,7 +51,6 @@ import org.springframework.core.io.buffer.NettyDataBufferFactory;
 import org.springframework.http.client.reactive.ReactorResourceFactory;
 import org.springframework.messaging.rsocket.RSocketRequester;
 import org.springframework.messaging.rsocket.RSocketStrategies;
-import org.springframework.util.SocketUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
@@ -97,11 +96,10 @@ class NettyRSocketServerFactoryTests {
 	void specificPort() {
 		NettyRSocketServerFactory factory = getFactory();
 		int specificPort = doWithRetry(() -> {
-			int port = SocketUtils.findAvailableTcpPort(41000);
-			factory.setPort(port);
+			factory.setPort(0);
 			this.server = factory.create(new EchoRequestResponseAcceptor());
 			this.server.start();
-			return port;
+			return this.server.address().getPort();
 		});
 		this.requester = createRSocketTcpClient();
 		assertThat(this.server.address().getPort()).isEqualTo(specificPort);

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatReactiveWebServerFactoryTests.java

@@ -16,10 +16,7 @@
 
 package org.springframework.boot.web.embedded.tomcat;
 
-import java.io.IOException;
 import java.net.ConnectException;
-import java.net.InetSocketAddress;
-import java.net.ServerSocket;
 import java.time.Duration;
 import java.util.Arrays;
 import java.util.Map;
@@ -48,7 +45,6 @@ import org.springframework.boot.web.server.PortInUseException;
 import org.springframework.boot.web.server.Shutdown;
 import org.springframework.boot.web.server.WebServerException;
 import org.springframework.http.server.reactive.HttpHandler;
-import org.springframework.util.SocketUtils;
 import org.springframework.web.reactive.function.client.WebClient;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -225,15 +221,13 @@ class TomcatReactiveWebServerFactoryTests extends AbstractReactiveWebServerFacto
 	}
 
 	@Test
-	void portClashOfPrimaryConnectorResultsInPortInUseException() throws IOException {
-		doWithBlockedPort((port) -> {
-			assertThatExceptionOfType(RuntimeException.class).isThrownBy(() -> {
-				AbstractReactiveWebServerFactory factory = getFactory();
-				factory.setPort(port);
-				this.webServer = factory.getWebServer(mock(HttpHandler.class));
-				this.webServer.start();
-			}).satisfies((ex) -> handleExceptionCausedByBlockedPortOnPrimaryConnector(ex, port));
-		});
+	void portClashOfPrimaryConnectorResultsInPortInUseException() throws Exception {
+		doWithBlockedPort((port) -> assertThatExceptionOfType(RuntimeException.class).isThrownBy(() -> {
+			AbstractReactiveWebServerFactory factory = getFactory();
+			factory.setPort(port);
+			this.webServer = factory.getWebServer(mock(HttpHandler.class));
+			this.webServer.start();
+		}).satisfies((ex) -> handleExceptionCausedByBlockedPortOnPrimaryConnector(ex, port)));
 	}
 
 	@Override
@@ -279,34 +273,9 @@ class TomcatReactiveWebServerFactoryTests extends AbstractReactiveWebServerFacto
 		assertThat(webServerReference).hasValue(webServer);
 	}
 
-	private void doWithBlockedPort(BlockedPortAction action) throws IOException {
-		int port = SocketUtils.findAvailableTcpPort(40000);
-		ServerSocket serverSocket = new ServerSocket();
-		for (int i = 0; i < 10; i++) {
-			try {
-				serverSocket.bind(new InetSocketAddress(port));
-				break;
-			}
-			catch (Exception ex) {
-			}
-		}
-		try {
-			action.run(port);
-		}
-		finally {
-			serverSocket.close();
-		}
-	}
-
 	private void handleExceptionCausedByBlockedPortOnPrimaryConnector(RuntimeException ex, int blockedPort) {
 		assertThat(ex).isInstanceOf(PortInUseException.class);
 		assertThat(((PortInUseException) ex).getPort()).isEqualTo(blockedPort);
 	}
 
-	interface BlockedPortAction {
-
-		void run(int port);
-
-	}
-
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/reactive/server/AbstractReactiveWebServerFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -20,6 +20,7 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.InetSocketAddress;
+import java.net.ServerSocket;
 import java.nio.charset.StandardCharsets;
 import java.security.KeyStore;
 import java.time.Duration;
@@ -73,7 +74,6 @@ import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
-import org.springframework.util.SocketUtils;
 import org.springframework.util.unit.DataSize;
 import org.springframework.web.reactive.function.BodyInserters;
 import org.springframework.web.reactive.function.client.WebClient;
@@ -109,11 +109,10 @@ public abstract class AbstractReactiveWebServerFactoryTests {
 	void specificPort() throws Exception {
 		AbstractReactiveWebServerFactory factory = getFactory();
 		int specificPort = doWithRetry(() -> {
-			int port = SocketUtils.findAvailableTcpPort(41000);
-			factory.setPort(port);
+			factory.setPort(0);
 			this.webServer = factory.getWebServer(new EchoHandler());
 			this.webServer.start();
-			return port;
+			return this.webServer.getPort();
 		});
 		Mono<String> result = getWebClient(this.webServer.getPort()).build().post().uri("/test")
 				.contentType(MediaType.TEXT_PLAIN).body(BodyInserters.fromValue("Hello World")).retrieve()
@@ -569,6 +568,26 @@ public abstract class AbstractReactiveWebServerFactoryTests {
 		throw new IllegalStateException("Action was not successful in 10 attempts", lastFailure);
 	}
 
+	protected final void doWithBlockedPort(BlockedPortAction action) throws Exception {
+		ServerSocket serverSocket = new ServerSocket();
+		int blockedPort = doWithRetry(() -> {
+			serverSocket.bind(null);
+			return serverSocket.getLocalPort();
+		});
+		try {
+			action.run(blockedPort);
+		}
+		finally {
+			serverSocket.close();
+		}
+	}
+
+	public interface BlockedPortAction {
+
+		void run(int port);
+
+	}
+
 	protected static class EchoHandler implements HttpHandler {
 
 		public EchoHandler() {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java

@@ -22,7 +22,6 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
 import java.net.InetAddress;
-import java.net.InetSocketAddress;
 import java.net.MalformedURLException;
 import java.net.ServerSocket;
 import java.net.URI;
@@ -140,7 +139,6 @@ import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.FileCopyUtils;
-import org.springframework.util.SocketUtils;
 import org.springframework.util.StreamUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -319,11 +317,10 @@ public abstract class AbstractServletWebServerFactoryTests {
 	void specificPort() throws Exception {
 		AbstractServletWebServerFactory factory = getFactory();
 		int specificPort = doWithRetry(() -> {
-			int port = SocketUtils.findAvailableTcpPort(41000);
-			factory.setPort(port);
+			factory.setPort(0);
 			this.webServer = factory.getWebServer(exampleServletRegistration());
 			this.webServer.start();
-			return port;
+			return this.webServer.getPort();
 		});
 		assertThat(getResponse("http://localhost:" + specificPort + "/hello")).isEqualTo("Hello World");
 		assertThat(this.webServer.getPort()).isEqualTo(specificPort);
@@ -1405,9 +1402,8 @@ public abstract class AbstractServletWebServerFactoryTests {
 	protected final void doWithBlockedPort(BlockedPortAction action) throws Exception {
 		ServerSocket serverSocket = new ServerSocket();
 		int blockedPort = doWithRetry(() -> {
-			int port = SocketUtils.findAvailableTcpPort(40000);
-			serverSocket.bind(new InetSocketAddress(port));
-			return port;
+			serverSocket.bind(null);
+			return serverSocket.getLocalPort();
 		});
 		try {
 			action.run(blockedPort);