Merge pull request #16733 from Johnny Lim

* gh-16733:
  Polish "Remove unnecessary latches in tests"
  Remove unnecessary latches in tests

Closes gh-16733

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/AbstractDevToolsDataSourceAutoConfigurationTests.java

@@ -20,7 +20,6 @@ import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Collection;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
@@ -95,11 +94,9 @@ public abstract class AbstractDevToolsDataSourceAutoConfigurationTests {
 
 	protected ConfigurableApplicationContext getContext(
 			Supplier<ConfigurableApplicationContext> supplier) throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
 		AtomicReference<ConfigurableApplicationContext> atomicReference = new AtomicReference<>();
 		Thread thread = new Thread(() -> {
 			ConfigurableApplicationContext context = supplier.get();
-			latch.countDown();
 			atomicReference.getAndSet(context);
 		});
 		thread.start();

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/LocalDevToolsAutoConfigurationTests.java

@@ -21,7 +21,6 @@ import java.time.Duration;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
@@ -253,11 +252,9 @@ public class LocalDevToolsAutoConfigurationTests {
 
 	private ConfigurableApplicationContext getContext(
 			Supplier<ConfigurableApplicationContext> supplier) throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
 		AtomicReference<ConfigurableApplicationContext> atomicReference = new AtomicReference<>();
 		Thread thread = new Thread(() -> {
 			ConfigurableApplicationContext context = supplier.get();
-			latch.countDown();
 			atomicReference.getAndSet(context);
 		});
 		thread.start();

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/RemoteDevToolsAutoConfigurationTests.java

@@ -16,7 +16,6 @@
 
 package org.springframework.boot.devtools.autoconfigure;
 
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
@@ -183,11 +182,9 @@ public class RemoteDevToolsAutoConfigurationTests {
 	private AnnotationConfigServletWebApplicationContext getContext(
 			Supplier<AnnotationConfigServletWebApplicationContext> supplier)
 			throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
 		AtomicReference<AnnotationConfigServletWebApplicationContext> atomicReference = new AtomicReference<>();
 		Thread thread = new Thread(() -> {
 			AnnotationConfigServletWebApplicationContext context = supplier.get();
-			latch.countDown();
 			atomicReference.getAndSet(context);
 		});
 		thread.start();

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/env/DevToolPropertiesIntegrationTests.java

@@ -18,7 +18,6 @@ package org.springframework.boot.devtools.env;
 
 import java.net.URL;
 import java.util.Collections;
-import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
@@ -122,11 +121,9 @@ public class DevToolPropertiesIntegrationTests {
 
 	protected ConfigurableApplicationContext getContext(
 			Supplier<ConfigurableApplicationContext> supplier) throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
 		AtomicReference<ConfigurableApplicationContext> atomicReference = new AtomicReference<>();
 		Thread thread = new Thread(() -> {
 			ConfigurableApplicationContext context = supplier.get();
-			latch.countDown();
 			atomicReference.getAndSet(context);
 		});
 		thread.start();

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/env/DevToolsHomePropertiesPostProcessorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2017 the original author or authors.
+ * 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.
@@ -21,7 +21,6 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Properties;
-import java.util.concurrent.CountDownLatch;
 
 import org.junit.Before;
 import org.junit.Rule;
@@ -74,11 +73,7 @@ public class DevToolsHomePropertiesPostProcessorTests {
 	}
 
 	protected void runPostProcessor(Runnable runnable) throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
+		Thread thread = new Thread(runnable);
-		Thread thread = new Thread(() -> {
-			runnable.run();
-			latch.countDown();
-		});
 		thread.start();
 		thread.join();
 	}