Use Awaitility in our own tests

Closes gh-18227

spring-boot-project/spring-boot-actuator/pom.xml

@@ -345,6 +345,11 @@
 			<artifactId>jersey-media-json-jackson</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>com.jayway.jsonpath</groupId>
 			<artifactId>json-path</artifactId>

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/management/HeapDumpWebEndpointWebIntegrationTests.java

@@ -18,8 +18,10 @@ package org.springframework.boot.actuate.management;
 
 import java.io.File;
 import java.io.IOException;
+import java.time.Duration;
 import java.util.concurrent.TimeUnit;
 
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.BeforeEach;
 
 import org.springframework.boot.actuate.endpoint.web.test.WebEndpointTest;
@@ -31,7 +33,7 @@ import org.springframework.http.MediaType;
 import org.springframework.test.web.reactive.server.WebTestClient;
 import org.springframework.util.FileCopyUtils;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.is;
 
 /**
  * Integration tests for {@link HeapDumpWebEndpoint} exposed by Jersey, Spring MVC, and
@@ -64,11 +66,7 @@ class HeapDumpWebEndpointWebIntegrationTests {
 	}
 
 	private void assertHeapDumpFileIsDeleted() throws InterruptedException {
-		long end = System.currentTimeMillis() + 5000;
-		while (System.currentTimeMillis() < end && this.endpoint.file.exists()) {
-			Thread.sleep(100);
-		}
-		assertThat(this.endpoint.file.exists()).isFalse();
+		Awaitility.waitAtMost(Duration.ofSeconds(5)).until(this.endpoint.file::exists, is(false));
 	}
 
 	@Configuration(proxyBeanMethods = false)

spring-boot-project/spring-boot-autoconfigure/pom.xml

@@ -897,6 +897,11 @@
 			<artifactId>tomcat-embed-jasper</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.hsqldb</groupId>
 			<artifactId>hsqldb</artifactId>

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java

@@ -19,6 +19,7 @@ package org.springframework.boot.autoconfigure.orm.jpa;
 import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -27,6 +28,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Consumer;
+import java.util.stream.Collectors;
 
 import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
@@ -37,6 +39,7 @@ import javax.transaction.TransactionManager;
 import javax.transaction.UserTransaction;
 
 import com.zaxxer.hikari.HikariDataSource;
+import org.awaitility.Awaitility;
 import org.hibernate.boot.model.naming.ImplicitNamingStrategy;
 import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
 import org.hibernate.cfg.AvailableSettings;
@@ -77,6 +80,7 @@ import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.entry;
+import static org.hamcrest.Matchers.hasSize;
 import static org.mockito.Mockito.mock;
 
 /**
@@ -387,12 +391,8 @@ class HibernateJpaAutoConfigurationTests extends AbstractJpaAutoConfigurationTes
 					assertThat(context).hasNotFailed();
 					EventCapturingApplicationListener listener = context
 							.getBean(EventCapturingApplicationListener.class);
-					long end = System.currentTimeMillis() + 30000;
-					while ((System.currentTimeMillis() < end) && !dataSourceSchemaCreatedEventReceived(listener)) {
-						Thread.sleep(100);
-					}
-					assertThat(listener.events.stream().filter(DataSourceSchemaCreatedEvent.class::isInstance))
-							.hasSize(1);
+					Awaitility.waitAtMost(Duration.ofSeconds(30))
+							.until(() -> dataSourceSchemaCreatedEventsReceivedBy(listener), hasSize(1));
 				});
 	}
 
@@ -408,13 +408,9 @@ class HibernateJpaAutoConfigurationTests extends AbstractJpaAutoConfigurationTes
 				});
 	}
 
-	private boolean dataSourceSchemaCreatedEventReceived(EventCapturingApplicationListener listener) {
-		for (ApplicationEvent event : listener.events) {
-			if (event instanceof DataSourceSchemaCreatedEvent) {
-				return true;
-			}
-		}
-		return false;
+	private List<ApplicationEvent> dataSourceSchemaCreatedEventsReceivedBy(EventCapturingApplicationListener listener) {
+		return listener.events.stream().filter(DataSourceSchemaCreatedEvent.class::isInstance)
+				.collect(Collectors.toList());
 	}
 
 	@Configuration(proxyBeanMethods = false)

spring-boot-project/spring-boot-devtools/pom.xml

@@ -130,6 +130,11 @@
 			<artifactId>HikariCP</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-webmvc</artifactId>

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/livereload/LiveReloadServerTests.java

@@ -20,12 +20,14 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URI;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 import org.apache.tomcat.websocket.WsWebSocketContainer;
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
@@ -43,6 +45,9 @@ import org.springframework.web.socket.client.standard.StandardWebSocketClient;
 import org.springframework.web.socket.handler.TextWebSocketHandler;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
 
 /**
  * Tests for {@link LiveReloadServer}.
@@ -107,10 +112,7 @@ class LiveReloadServerTests {
 	}
 
 	private void awaitClosedException() throws InterruptedException {
-		long startTime = System.currentTimeMillis();
-		while (this.server.getClosedExceptions().isEmpty() && System.currentTimeMillis() - startTime < 10000) {
-			Thread.sleep(100);
-		}
+		Awaitility.waitAtMost(Duration.ofSeconds(10)).until(this.server::getClosedExceptions, is(not(empty())));
 	}
 
 	@Test

spring-boot-project/spring-boot-tools/spring-boot-loader/pom.xml

@@ -21,14 +21,19 @@
 			<optional>true</optional>
 		</dependency>
 		<!-- Test -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-test-support</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>ch.qos.logback</groupId>
 			<artifactId>logback-classic</artifactId>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-webmvc</artifactId>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
 			<scope>test</scope>
 		</dependency>
 		<dependency>
@@ -39,8 +44,8 @@
 			<scope>test</scope>
 		</dependency>
 		<dependency>
-			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-test-support</artifactId>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/PropertiesLauncherTests.java

@@ -21,6 +21,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -28,6 +29,7 @@ import java.util.jar.Attributes;
 import java.util.jar.Manifest;
 
 import org.assertj.core.api.Condition;
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -44,6 +46,7 @@ import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+import static org.hamcrest.Matchers.containsString;
 
 /**
  * Tests for {@link PropertiesLauncher}.
@@ -339,14 +342,7 @@ class PropertiesLauncherTests {
 	}
 
 	private void waitFor(String value) throws Exception {
-		int count = 0;
-		boolean timeout = false;
-		while (!timeout && count < 100) {
-			count++;
-			Thread.sleep(50L);
-			timeout = this.output.toString().contains(value);
-		}
-		assertThat(timeout).as("Timed out waiting for (" + value + ")").isTrue();
+		Awaitility.waitAtMost(Duration.ofSeconds(5)).until(this.output::toString, containsString(value));
 	}
 
 	private Condition<Archive> endingWith(String value) {

spring-boot-project/spring-boot/pom.xml

@@ -421,6 +421,11 @@
 			<artifactId>httpasyncclient</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.firebirdsql.jdbc</groupId>
 			<artifactId>jaybird-jdk18</artifactId>

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/undertow/UndertowReactiveWebServerFactoryTests.java

@@ -23,6 +23,7 @@ import java.time.Duration;
 import java.util.Arrays;
 
 import io.undertow.Undertow;
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 import org.mockito.InOrder;
@@ -36,6 +37,7 @@ import org.springframework.web.reactive.function.client.WebClient;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.hamcrest.Matchers.is;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
@@ -124,11 +126,8 @@ class UndertowReactiveWebServerFactoryTests extends AbstractReactiveWebServerFac
 		assertThat(accessLogDirectory.listFiles()).contains(accessLog);
 	}
 
-	private void awaitFile(File file) throws InterruptedException {
-		long end = System.currentTimeMillis() + 10000;
-		while (!file.exists() && System.currentTimeMillis() < end) {
-			Thread.sleep(100);
-		}
+	private void awaitFile(File file) {
+		Awaitility.waitAtMost(Duration.ofSeconds(10)).until(file::exists, is(true));
 	}
 
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/undertow/UndertowServletWebServerFactoryTests.java

@@ -21,6 +21,7 @@ import java.io.IOException;
 import java.net.SocketException;
 import java.net.URISyntaxException;
 import java.nio.charset.Charset;
+import java.time.Duration;
 import java.util.Arrays;
 import java.util.Locale;
 import java.util.Map;
@@ -34,6 +35,7 @@ import io.undertow.Undertow.Builder;
 import io.undertow.servlet.api.DeploymentInfo;
 import io.undertow.servlet.api.ServletContainer;
 import org.apache.jasper.servlet.JspServlet;
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
 import org.mockito.InOrder;
 
@@ -49,6 +51,7 @@ import org.springframework.test.util.ReflectionTestUtils;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIOException;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.hamcrest.Matchers.is;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
@@ -234,11 +237,8 @@ class UndertowServletWebServerFactoryTests extends AbstractServletWebServerFacto
 		return null; // Undertow does not support JSPs
 	}
 
-	private void awaitFile(File file) throws InterruptedException {
-		long end = System.currentTimeMillis() + 10000;
-		while (!file.exists() && System.currentTimeMillis() < end) {
-			Thread.sleep(100);
-		}
+	private void awaitFile(File file) {
+		Awaitility.waitAtMost(Duration.ofSeconds(10)).until(file::exists, is(true));
 	}
 
 	private ServletContainer getServletContainerFromNewFactory() {

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/pom.xml

@@ -21,6 +21,10 @@
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>net.bytebuddy</groupId>
+			<artifactId>byte-buddy</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
@@ -32,8 +36,9 @@
 			<scope>test</scope>
 		</dependency>
 		<dependency>
-			<groupId>net.bytebuddy</groupId>
-			<artifactId>byte-buddy</artifactId>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
 		</dependency>
 	</dependencies>
 	<build>

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/AbstractDevToolsIntegrationTests.java

+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.devtools.tests;
+
+import java.io.File;
+import java.time.Duration;
+import java.util.ArrayList;
+import java.util.List;
+
+import net.bytebuddy.ByteBuddy;
+import net.bytebuddy.description.annotation.AnnotationDescription;
+import net.bytebuddy.description.modifier.Visibility;
+import net.bytebuddy.dynamic.DynamicType;
+import net.bytebuddy.implementation.FixedValue;
+import org.awaitility.Awaitility;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.boot.testsupport.BuildOutput;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * Base class for DevTools integration tests.
+ *
+ * @author Andy Wilkinson
+ */
+abstract class AbstractDevToolsIntegrationTests {
+
+	protected static final BuildOutput buildOutput = new BuildOutput(AbstractDevToolsIntegrationTests.class);
+
+	protected final File serverPortFile = new File(buildOutput.getRootLocation(), "server.port");
+
+	@RegisterExtension
+	protected final JvmLauncher javaLauncher = new JvmLauncher();
+
+	@TempDir
+	protected static File temp;
+
+	protected LaunchedApplication launchedApplication;
+
+	protected void launchApplication(ApplicationLauncher applicationLauncher, String... args) throws Exception {
+		this.serverPortFile.delete();
+		this.launchedApplication = applicationLauncher.launchApplication(this.javaLauncher, this.serverPortFile, args);
+	}
+
+	@AfterEach
+	void stopApplication() throws InterruptedException {
+		this.launchedApplication.stop();
+	}
+
+	protected int awaitServerPort() throws Exception {
+		int port = Awaitility.waitAtMost(Duration.ofSeconds(30))
+				.until(() -> new ApplicationState(this.serverPortFile, this.launchedApplication),
+						ApplicationState::hasServerPort)
+				.getServerPort();
+		this.serverPortFile.delete();
+		System.out.println("Got port " + port);
+		this.launchedApplication.restartRemote(port);
+		Thread.sleep(1000);
+		return port;
+	}
+
+	protected ControllerBuilder controller(String name) {
+		return new ControllerBuilder(name, this.launchedApplication.getClassesDirectory());
+	}
+
+	protected static final class ControllerBuilder {
+
+		private final List<String> mappings = new ArrayList<>();
+
+		private final String name;
+
+		private final File classesDirectory;
+
+		protected ControllerBuilder(String name, File classesDirectory) {
+			this.name = name;
+			this.classesDirectory = classesDirectory;
+		}
+
+		protected ControllerBuilder withRequestMapping(String mapping) {
+			this.mappings.add(mapping);
+			return this;
+		}
+
+		protected void build() throws Exception {
+			DynamicType.Builder<Object> builder = new ByteBuddy().subclass(Object.class).name(this.name)
+					.annotateType(AnnotationDescription.Builder.ofType(RestController.class).build());
+			for (String mapping : this.mappings) {
+				builder = builder.defineMethod(mapping, String.class, Visibility.PUBLIC)
+						.intercept(FixedValue.value(mapping)).annotateMethod(AnnotationDescription.Builder
+								.ofType(RequestMapping.class).defineArray("value", mapping).build());
+			}
+			builder.make().saveIn(this.classesDirectory);
+		}
+
+	}
+
+}

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/ApplicationState.java

+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.devtools.tests;
+
+import java.io.File;
+
+import org.springframework.boot.devtools.tests.JvmLauncher.LaunchedJvm;
+
+/**
+ * State of an application.
+ *
+ * @author Andy Wilkinson
+ */
+final class ApplicationState {
+
+	private final Integer serverPort;
+
+	private final FileContents out;
+
+	private final FileContents err;
+
+	ApplicationState(File serverPortFile, LaunchedJvm jvm) {
+		this(serverPortFile, jvm.getStandardOut(), jvm.getStandardError());
+	}
+
+	ApplicationState(File serverPortFile, LaunchedApplication application) {
+		this(serverPortFile, application.getStandardOut(), application.getStandardError());
+	}
+
+	private ApplicationState(File serverPortFile, File out, File err) {
+		this.serverPort = new FileContents(serverPortFile).get(Integer::parseInt);
+		this.out = new FileContents(out);
+		this.err = new FileContents(err);
+	}
+
+	boolean hasServerPort() {
+		return this.serverPort != null;
+	}
+
+	int getServerPort() {
+		return this.serverPort;
+	}
+
+	@Override
+	public String toString() {
+		return String.format("Application output:%n%s%n%s", this.out, this.err);
+	}
+
+}

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/DevToolsIntegrationTests.java

@@ -17,29 +17,13 @@
 package org.springframework.boot.devtools.tests;
 
 import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
-import java.time.Duration;
-import java.util.ArrayList;
-import java.util.List;
 
-import net.bytebuddy.ByteBuddy;
-import net.bytebuddy.description.annotation.AnnotationDescription;
-import net.bytebuddy.description.modifier.Visibility;
-import net.bytebuddy.dynamic.DynamicType.Builder;
-import net.bytebuddy.implementation.FixedValue;
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.extension.RegisterExtension;
-import org.junit.jupiter.api.io.TempDir;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 
 import org.springframework.boot.test.web.client.TestRestTemplate;
-import org.springframework.boot.testsupport.BuildOutput;
 import org.springframework.http.HttpStatus;
-import org.springframework.util.FileCopyUtils;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -48,29 +32,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Andy Wilkinson
  */
-public class DevToolsIntegrationTests {
-
-	@TempDir
-	static File temp;
-
-	private static final BuildOutput buildOutput = new BuildOutput(DevToolsIntegrationTests.class);
-
-	private LaunchedApplication launchedApplication;
-
-	private final File serverPortFile = new File(buildOutput.getRootLocation(), "server.port");
-
-	@RegisterExtension
-	final JvmLauncher javaLauncher = new JvmLauncher();
-
-	private void launchApplication(ApplicationLauncher applicationLauncher) throws Exception {
-		this.serverPortFile.delete();
-		this.launchedApplication = applicationLauncher.launchApplication(this.javaLauncher, this.serverPortFile);
-	}
-
-	@AfterEach
-	void stopApplication() throws InterruptedException {
-		this.launchedApplication.stop();
-	}
+public class DevToolsIntegrationTests extends AbstractDevToolsIntegrationTests {
 
 	@ParameterizedTest(name = "{0}")
 	@MethodSource("parameters")
@@ -191,33 +153,6 @@ public class DevToolsIntegrationTests {
 				.isEqualTo(HttpStatus.NOT_FOUND);
 	}
 
-	private int awaitServerPort() throws Exception {
-		Duration timeToWait = Duration.ofSeconds(40);
-		long end = System.currentTimeMillis() + timeToWait.toMillis();
-		System.out.println("Reading server port from '" + this.serverPortFile + "'");
-		while (this.serverPortFile.length() == 0) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException(String.format(
-						"server.port file '" + this.serverPortFile + "' was not written within " + timeToWait.toMillis()
-								+ "ms. Application output:%n%s%s",
-						FileCopyUtils.copyToString(new FileReader(this.launchedApplication.getStandardOut())),
-						FileCopyUtils.copyToString(new FileReader(this.launchedApplication.getStandardError()))));
-			}
-			Thread.sleep(100);
-		}
-		FileReader portReader = new FileReader(this.serverPortFile);
-		int port = Integer.valueOf(FileCopyUtils.copyToString(portReader));
-		this.serverPortFile.delete();
-		System.out.println("Got port " + port);
-		this.launchedApplication.restartRemote(port);
-		Thread.sleep(1000);
-		return port;
-	}
-
-	private ControllerBuilder controller(String name) {
-		return new ControllerBuilder(name, this.launchedApplication.getClassesDirectory());
-	}
-
 	static Object[] parameters() throws IOException {
 		Directories directories = new Directories(buildOutput, temp);
 		return new Object[] { new Object[] { new LocalApplicationLauncher(directories) },
@@ -225,35 +160,4 @@ public class DevToolsIntegrationTests {
 				new Object[] { new JarFileRemoteApplicationLauncher(directories) } };
 	}
 
-	private static final class ControllerBuilder {
-
-		private final List<String> mappings = new ArrayList<>();
-
-		private final String name;
-
-		private final File classesDirectory;
-
-		private ControllerBuilder(String name, File classesDirectory) {
-			this.name = name;
-			this.classesDirectory = classesDirectory;
-		}
-
-		ControllerBuilder withRequestMapping(String mapping) {
-			this.mappings.add(mapping);
-			return this;
-		}
-
-		void build() throws Exception {
-			Builder<Object> builder = new ByteBuddy().subclass(Object.class).name(this.name)
-					.annotateType(AnnotationDescription.Builder.ofType(RestController.class).build());
-			for (String mapping : this.mappings) {
-				builder = builder.defineMethod(mapping, String.class, Visibility.PUBLIC)
-						.intercept(FixedValue.value(mapping)).annotateMethod(AnnotationDescription.Builder
-								.ofType(RequestMapping.class).defineArray("value", mapping).build());
-			}
-			builder.make().saveIn(this.classesDirectory);
-		}
-
-	}
-
 }

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/DevToolsWithLazyInitializationIntegrationTests.java

@@ -16,30 +16,13 @@
 
 package org.springframework.boot.devtools.tests;
 
-import java.io.File;
-import java.io.FileReader;
 import java.io.IOException;
-import java.time.Duration;
-import java.util.ArrayList;
-import java.util.List;
 
-import net.bytebuddy.ByteBuddy;
-import net.bytebuddy.description.annotation.AnnotationDescription;
-import net.bytebuddy.description.modifier.Visibility;
-import net.bytebuddy.dynamic.DynamicType;
-import net.bytebuddy.implementation.FixedValue;
-import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.extension.RegisterExtension;
-import org.junit.jupiter.api.io.TempDir;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 
 import org.springframework.boot.test.web.client.TestRestTemplate;
-import org.springframework.boot.testsupport.BuildOutput;
 import org.springframework.http.HttpStatus;
-import org.springframework.util.FileCopyUtils;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -48,36 +31,13 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Madhura Bhave
  */
-public class DevToolsWithLazyInitializationIntegrationTests {
-
-	@TempDir
-	static File temp;
-
-	private static final BuildOutput buildOutput = new BuildOutput(DevToolsIntegrationTests.class);
-
-	private LaunchedApplication launchedApplication;
-
-	private final File serverPortFile = new File(buildOutput.getRootLocation(), "server.port");
-
-	@RegisterExtension
-	final JvmLauncher javaLauncher = new JvmLauncher();
-
-	private void launchApplication(ApplicationLauncher applicationLauncher) throws Exception {
-		this.serverPortFile.delete();
-		this.launchedApplication = applicationLauncher.launchApplication(this.javaLauncher, this.serverPortFile,
-				"--spring.main.lazy-initialization=true");
-	}
-
-	@AfterEach
-	void stopApplication() throws InterruptedException {
-		this.launchedApplication.stop();
-	}
+public class DevToolsWithLazyInitializationIntegrationTests extends AbstractDevToolsIntegrationTests {
 
 	@ParameterizedTest(name = "{0}")
 	@MethodSource("parameters")
 	public void addARequestMappingToAnExistingControllerWhenLazyInit(ApplicationLauncher applicationLauncher)
 			throws Exception {
-		launchApplication(applicationLauncher);
+		launchApplication(applicationLauncher, "--spring.main.lazy-initialization=true");
 		TestRestTemplate template = new TestRestTemplate();
 		String urlBase = "http://localhost:" + awaitServerPort();
 		assertThat(template.getForObject(urlBase + "/one", String.class)).isEqualTo("one");
@@ -89,33 +49,6 @@ public class DevToolsWithLazyInitializationIntegrationTests {
 		assertThat(template.getForObject(urlBase + "/two", String.class)).isEqualTo("two");
 	}
 
-	private int awaitServerPort() throws Exception {
-		Duration timeToWait = Duration.ofSeconds(40);
-		long end = System.currentTimeMillis() + timeToWait.toMillis();
-		System.out.println("Reading server port from '" + this.serverPortFile + "'");
-		while (this.serverPortFile.length() == 0) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException(String.format(
-						"server.port file '" + this.serverPortFile + "' was not written within " + timeToWait.toMillis()
-								+ "ms. Application output:%n%s%s",
-						FileCopyUtils.copyToString(new FileReader(this.launchedApplication.getStandardOut())),
-						FileCopyUtils.copyToString(new FileReader(this.launchedApplication.getStandardError()))));
-			}
-			Thread.sleep(100);
-		}
-		FileReader portReader = new FileReader(this.serverPortFile);
-		int port = Integer.valueOf(FileCopyUtils.copyToString(portReader));
-		this.serverPortFile.delete();
-		System.out.println("Got port " + port);
-		this.launchedApplication.restartRemote(port);
-		Thread.sleep(1000);
-		return port;
-	}
-
-	private ControllerBuilder controller(String name) {
-		return new ControllerBuilder(name, this.launchedApplication.getClassesDirectory());
-	}
-
 	static Object[] parameters() throws IOException {
 		Directories directories = new Directories(buildOutput, temp);
 		return new Object[] { new Object[] { new LocalApplicationLauncher(directories) },
@@ -124,35 +57,4 @@ public class DevToolsWithLazyInitializationIntegrationTests {
 
 	}
 
-	private static final class ControllerBuilder {
-
-		private final List<String> mappings = new ArrayList<>();
-
-		private final String name;
-
-		private final File classesDirectory;
-
-		private ControllerBuilder(String name, File classesDirectory) {
-			this.name = name;
-			this.classesDirectory = classesDirectory;
-		}
-
-		ControllerBuilder withRequestMapping(String mapping) {
-			this.mappings.add(mapping);
-			return this;
-		}
-
-		void build() throws Exception {
-			DynamicType.Builder<Object> builder = new ByteBuddy().subclass(Object.class).name(this.name)
-					.annotateType(AnnotationDescription.Builder.ofType(RestController.class).build());
-			for (String mapping : this.mappings) {
-				builder = builder.defineMethod(mapping, String.class, Visibility.PUBLIC)
-						.intercept(FixedValue.value(mapping)).annotateMethod(AnnotationDescription.Builder
-								.ofType(RequestMapping.class).defineArray("value", mapping).build());
-			}
-			builder.make().saveIn(this.classesDirectory);
-		}
-
-	}
-
 }

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/FileContents.java

+/*
+ * Copyright 2012-2019 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.devtools.tests;
+
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.util.function.Function;
+
+import org.springframework.util.FileCopyUtils;
+
+/**
+ * Provides access to the contents of a file.
+ *
+ * @author Andy Wilkinson
+ */
+class FileContents {
+
+	private final File file;
+
+	FileContents(File file) {
+		this.file = file;
+	}
+
+	String get() {
+		return get(Function.identity());
+	}
+
+	<T> T get(Function<String, T> transformer) {
+		if ((!this.file.exists()) || this.file.length() == 0) {
+			return null;
+		}
+		try {
+			return transformer.apply(FileCopyUtils.copyToString(new FileReader(this.file)));
+		}
+		catch (IOException ex) {
+			throw new RuntimeException(ex);
+		}
+	}
+
+	@Override
+	public String toString() {
+		return get();
+	}
+
+}

spring-boot-tests/spring-boot-integration-tests/spring-boot-devtools-tests/src/test/java/org/springframework/boot/devtools/tests/RemoteApplicationLauncher.java

@@ -17,17 +17,20 @@
 package org.springframework.boot.devtools.tests;
 
 import java.io.File;
-import java.io.FileReader;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.BiFunction;
 
+import org.awaitility.Awaitility;
+
 import org.springframework.boot.devtools.RemoteSpringApplication;
 import org.springframework.boot.devtools.tests.JvmLauncher.LaunchedJvm;
-import org.springframework.util.FileCopyUtils;
 import org.springframework.util.StringUtils;
 
+import static org.hamcrest.Matchers.containsString;
+
 /**
  * Base class for {@link ApplicationLauncher} implementations that use
  * {@link RemoteSpringApplication}.
@@ -45,7 +48,7 @@ abstract class RemoteApplicationLauncher extends AbstractApplicationLauncher {
 		LaunchedJvm applicationJvm = javaLauncher.launch("app", createApplicationClassPath(),
 				"com.example.DevToolsTestApplication", serverPortFile.getAbsolutePath(), "--server.port=0",
 				"--spring.devtools.remote.secret=secret");
-		int port = awaitServerPort(applicationJvm.getStandardOut(), serverPortFile);
+		int port = awaitServerPort(applicationJvm, serverPortFile);
 		BiFunction<Integer, File, Process> remoteRestarter = getRemoteRestarter(javaLauncher);
 		return new LaunchedApplication(getDirectories().getRemoteAppDirectory(), applicationJvm.getStandardOut(),
 				applicationJvm.getStandardError(), applicationJvm.getProcess(), remoteRestarter.apply(port, null),
@@ -60,7 +63,7 @@ abstract class RemoteApplicationLauncher extends AbstractApplicationLauncher {
 		args.addAll(Arrays.asList(additionalArgs));
 		LaunchedJvm applicationJvm = javaLauncher.launch("app", createApplicationClassPath(),
 				args.toArray(new String[] {}));
-		int port = awaitServerPort(applicationJvm.getStandardOut(), serverPortFile);
+		int port = awaitServerPort(applicationJvm, serverPortFile);
 		BiFunction<Integer, File, Process> remoteRestarter = getRemoteRestarter(javaLauncher);
 		return new LaunchedApplication(getDirectories().getRemoteAppDirectory(), applicationJvm.getStandardOut(),
 				applicationJvm.getStandardError(), applicationJvm.getProcess(), remoteRestarter.apply(port, null),
@@ -96,35 +99,16 @@ abstract class RemoteApplicationLauncher extends AbstractApplicationLauncher {
 		return StringUtils.collectionToDelimitedString(entries, File.pathSeparator);
 	}
 
-	private int awaitServerPort(File standardOut, File serverPortFile) throws Exception {
-		long end = System.currentTimeMillis() + 30000;
-		while (serverPortFile.length() == 0) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException(
-						String.format("server.port file was not written within 30 seconds. Application output:%n%s",
-								FileCopyUtils.copyToString(new FileReader(standardOut))));
-			}
-			Thread.sleep(100);
-		}
-		FileReader portReader = new FileReader(serverPortFile);
-		int port = Integer.valueOf(FileCopyUtils.copyToString(portReader));
-		return port;
+	private int awaitServerPort(LaunchedJvm jvm, File serverPortFile) throws Exception {
+		return Awaitility.waitAtMost(Duration.ofSeconds(30))
+				.until(() -> new ApplicationState(serverPortFile, jvm), ApplicationState::hasServerPort)
+				.getServerPort();
 	}
 
 	private void awaitRemoteSpringApplication(File standardOut) throws Exception {
-		long end = System.currentTimeMillis() + 30000;
-		while (!standardOut.exists()) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException("Standard out file was not written within 30 seconds");
-			}
-			Thread.sleep(100);
-		}
-		while (!FileCopyUtils.copyToString(new FileReader(standardOut)).contains("Started RemoteSpringApplication")) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException("RemoteSpringApplication did not start within 30 seconds");
-			}
-			Thread.sleep(100);
-		}
+		FileContents contents = new FileContents(standardOut);
+		Awaitility.waitAtMost(Duration.ofSeconds(30)).until(contents::get,
+				containsString("Started RemoteSpringApplication"));
 	}
 
 }

spring-boot-tests/spring-boot-integration-tests/spring-boot-server-tests/pom.xml

@@ -45,6 +45,11 @@
 			<version>3.0.0</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.eclipse.jetty</groupId>
 			<artifactId>jetty-webapp</artifactId>

spring-boot-tests/spring-boot-integration-tests/spring-boot-server-tests/src/test/java/org/springframework/boot/context/embedded/AbstractApplicationLauncher.java

@@ -21,9 +21,11 @@ import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintStream;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.BeforeEachCallback;
 import org.junit.jupiter.api.extension.ExtensionContext;
@@ -93,16 +95,12 @@ abstract class AbstractApplicationLauncher implements BeforeEachCallback, AfterE
 	}
 
 	private int awaitServerPort(Process process, File serverPortFile) throws Exception {
-		long end = System.currentTimeMillis() + 30000;
-		while (serverPortFile.length() == 0) {
-			if (System.currentTimeMillis() > end) {
-				throw new IllegalStateException("server.port file was not written within 30 seconds");
-			}
+		Awaitility.waitAtMost(Duration.ofSeconds(30)).until(serverPortFile::length, (length) -> {
 			if (!process.isAlive()) {
-				throw new IllegalStateException("Application failed to launch");
+				throw new IllegalStateException("Application failed to start");
 			}
-			Thread.sleep(100);
-		}
+			return length > 0;
+		});
 		return Integer.parseInt(FileCopyUtils.copyToString(new FileReader(serverPortFile)));
 	}
 

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-integration/pom.xml

@@ -35,6 +35,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 	<build>
 		<plugins>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-integration/src/test/java/smoketest/integration/consumer/SampleIntegrationApplicationTests.java

@@ -20,11 +20,9 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Path;
-import java.util.concurrent.Callable;
-import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
+import java.time.Duration;
 
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -39,7 +37,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.ResourcePatternUtils;
 import org.springframework.util.StreamUtils;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.containsString;
 
 /**
  * Basic integration tests for service demo application.
@@ -66,8 +64,7 @@ class SampleIntegrationApplicationTests {
 				"--service.output-dir=" + outputDir);
 		SpringApplication.run(ProducerApplication.class, "World", "--service.input-dir=" + inputDir,
 				"--service.output-dir=" + outputDir);
-		String output = getOutput(outputDir);
-		assertThat(output).contains("Hello World");
+		awaitOutputContaining(outputDir, "Hello World");
 	}
 
 	@Test
@@ -76,41 +73,35 @@ class SampleIntegrationApplicationTests {
 		File outputDir = new File(temp.toFile(), "output");
 		this.context = SpringApplication.run(SampleIntegrationApplication.class, "testviamg",
 				"--service.input-dir=" + inputDir, "--service.output-dir=" + outputDir);
-		String output = getOutput(this.context.getBean(ServiceProperties.class).getOutputDir());
-		assertThat(output).contains("testviamg");
+		awaitOutputContaining(this.context.getBean(ServiceProperties.class).getOutputDir(), "testviamg");
 	}
 
-	private String getOutput(File outputDir) throws Exception {
-		Future<String> future = Executors.newSingleThreadExecutor().submit(new Callable<String>() {
-			@Override
-			public String call() throws Exception {
-				Resource[] resources = getResourcesWithContent(outputDir);
-				while (resources.length == 0) {
-					Thread.sleep(200);
-					resources = getResourcesWithContent(outputDir);
-				}
-				StringBuilder builder = new StringBuilder();
-				for (Resource resource : resources) {
-					try (InputStream inputStream = resource.getInputStream()) {
-						builder.append(new String(StreamUtils.copyToByteArray(inputStream)));
-					}
-				}
-				return builder.toString();
-			}
-		});
-		return future.get(30, TimeUnit.SECONDS);
+	private void awaitOutputContaining(File outputDir, String requiredContents) throws Exception {
+		Awaitility.waitAtMost(Duration.ofSeconds(30)).until(() -> outputIn(outputDir),
+				containsString(requiredContents));
+	}
+
+	private String outputIn(File outputDir) throws IOException {
+		Resource[] resources = findResources(outputDir);
+		if (resources.length == 0) {
+			return null;
+		}
+		return readResources(resources);
+	}
+
+	private Resource[] findResources(File outputDir) throws IOException {
+		return ResourcePatternUtils.getResourcePatternResolver(new DefaultResourceLoader())
+				.getResources("file:" + outputDir.getAbsolutePath() + "/*.txt");
 	}
 
-	private Resource[] getResourcesWithContent(File outputDir) throws IOException {
-		Resource[] candidates = ResourcePatternUtils.getResourcePatternResolver(new DefaultResourceLoader())
-				.getResources("file:" + outputDir.getAbsolutePath() + "/**");
-		for (Resource candidate : candidates) {
-			if ((candidate.getFilename() != null && candidate.getFilename().endsWith(".writing"))
-					|| candidate.contentLength() == 0) {
-				return new Resource[0];
+	private String readResources(Resource[] resources) throws IOException {
+		StringBuilder builder = new StringBuilder();
+		for (Resource resource : resources) {
+			try (InputStream input = resource.getInputStream()) {
+				builder.append(new String(StreamUtils.copyToByteArray(input)));
 			}
 		}
-		return candidates;
+		return builder.toString();
 	}
 
 }

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-kafka/pom.xml

@@ -29,6 +29,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.kafka</groupId>
 			<artifactId>spring-kafka-test</artifactId>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-kafka/src/test/java/smoketest/kafka/SampleKafkaApplicationTests.java

@@ -15,6 +15,9 @@
  */
 package smoketest.kafka;
 
+import java.time.Duration;
+
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
@@ -22,6 +25,8 @@ import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.kafka.test.context.EmbeddedKafka;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.empty;
+import static org.hamcrest.Matchers.not;
 
 /**
  * Integration tests for demo application.
@@ -39,10 +44,7 @@ class SampleKafkaApplicationTests {
 
 	@Test
 	void testVanillaExchange() throws Exception {
-		long end = System.currentTimeMillis() + 10000;
-		while (this.consumer.getMessages().isEmpty() && System.currentTimeMillis() < end) {
-			Thread.sleep(250);
-		}
+		Awaitility.waitAtMost(Duration.ofSeconds(30)).until(this.consumer::getMessages, not(empty()));
 		assertThat(this.consumer.getMessages()).extracting("message").containsOnly("A simple test message");
 	}
 

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-parent-context/pom.xml

@@ -34,6 +34,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 	<build>
 		<plugins>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-parent-context/src/test/java/smoketest/parent/consumer/SampleIntegrationParentApplicationTests.java

@@ -20,7 +20,9 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.file.Path;
+import java.time.Duration;
 
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 import smoketest.parent.SampleParentContextApplication;
@@ -33,7 +35,7 @@ import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.ResourcePatternUtils;
 import org.springframework.util.StreamUtils;
 
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.hamcrest.Matchers.containsString;
 
 /**
  * Basic integration tests for service demo application.
@@ -65,26 +67,16 @@ class SampleIntegrationParentApplicationTests {
 	}
 
 	private void awaitOutputContaining(File outputDir, String requiredContents) throws Exception {
-		long endTime = System.currentTimeMillis() + 30000;
-		String output = null;
-		while (System.currentTimeMillis() < endTime) {
-			Resource[] resources = findResources(outputDir);
-			if (resources.length == 0) {
-				Thread.sleep(200);
-				resources = findResources(outputDir);
-			}
-			else {
-				output = readResources(resources);
-				if (output != null && output.contains(requiredContents)) {
-					return;
-				}
-				else {
-					Thread.sleep(200);
-					output = readResources(resources);
-				}
-			}
+		Awaitility.waitAtMost(Duration.ofSeconds(30)).until(() -> outputIn(outputDir),
+				containsString(requiredContents));
+	}
+
+	private String outputIn(File outputDir) throws IOException {
+		Resource[] resources = findResources(outputDir);
+		if (resources.length == 0) {
+			return null;
 		}
-		fail("Timed out awaiting output containing '" + requiredContents + "'. Output was '" + output + "'");
+		return readResources(resources);
 	}
 
 	private Resource[] findResources(File outputDir) throws IOException {

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-quartz/pom.xml

@@ -35,6 +35,11 @@
 			<artifactId>spring-boot-starter-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.awaitility</groupId>
+			<artifactId>awaitility</artifactId>
+			<scope>test</scope>
+		</dependency>
 	</dependencies>
 	<build>
 		<plugins>

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-quartz/src/test/java/smoketest/quartz/SampleQuartzApplicationTests.java

@@ -16,6 +16,9 @@
 
 package smoketest.quartz;
 
+import java.time.Duration;
+
+import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 
@@ -24,7 +27,7 @@ import org.springframework.boot.test.system.CapturedOutput;
 import org.springframework.boot.test.system.OutputCaptureExtension;
 import org.springframework.context.ConfigurableApplicationContext;
 
-import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.containsString;
 
 /**
  * Tests for {@link SampleQuartzApplication}.
@@ -37,11 +40,7 @@ class SampleQuartzApplicationTests {
 	@Test
 	void quartzJobIsTriggered(CapturedOutput output) throws InterruptedException {
 		try (ConfigurableApplicationContext context = SpringApplication.run(SampleQuartzApplication.class)) {
-			long end = System.currentTimeMillis() + 5000;
-			while ((!output.toString().contains("Hello World!")) && System.currentTimeMillis() < end) {
-				Thread.sleep(100);
-			}
-			assertThat(output).contains("Hello World!");
+			Awaitility.waitAtMost(Duration.ofSeconds(5)).until(output::toString, containsString("Hello World!"));
 		}
 	}