diff --git a/buildSrc/src/main/java/org/springframework/build/compile/CompilerConventionsPlugin.java b/buildSrc/src/main/java/org/springframework/build/compile/CompilerConventionsPlugin.java
index 5cb9a70a37e..0b87a6136d8 100644
--- a/buildSrc/src/main/java/org/springframework/build/compile/CompilerConventionsPlugin.java
+++ b/buildSrc/src/main/java/org/springframework/build/compile/CompilerConventionsPlugin.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -33,6 +33,7 @@ import org.gradle.api.tasks.compile.JavaCompile;
  * with a dedicated property on the CLI: {@code "./gradlew test -PjavaSourceVersion=11"}.
  *
  * @author Brian Clozel
+ * @author Sam Brannen
  */
 public class CompilerConventionsPlugin implements Plugin<Project> {
 
@@ -40,13 +41,13 @@ public class CompilerConventionsPlugin implements Plugin<Project> {
 	 * The project property that can be used to switch the Java source
 	 * compatibility version for building source and test classes.
 	 */
-	public static String JAVA_SOURCE_VERSION_PROPERTY = "javaSourceVersion";
+	public static final String JAVA_SOURCE_VERSION_PROPERTY = "javaSourceVersion";
 
-	public static JavaVersion DEFAULT_COMPILER_VERSION = JavaVersion.VERSION_1_8;
+	public static final JavaVersion DEFAULT_COMPILER_VERSION = JavaVersion.VERSION_1_8;
 
-	private static List<String> COMPILER_ARGS;
+	private static final List<String> COMPILER_ARGS;
 
-	private static List<String> TEST_COMPILER_ARGS;
+	private static final List<String> TEST_COMPILER_ARGS;
 
 	static {
 		List<String> commonCompilerArgs = Arrays.asList(
@@ -72,7 +73,8 @@ public class CompilerConventionsPlugin implements Plugin<Project> {
 	}
 
 	/**
-	 * Applies the common Java compiler options for sources and test sources.
+	 * Applies the common Java compiler options for main sources, test fixture sources, and
+	 * test sources.
 	 * @param project the current project
 	 */
 	private void applyJavaCompileConventions(Project project) {
@@ -93,10 +95,12 @@ public class CompilerConventionsPlugin implements Plugin<Project> {
 					compileTask.getOptions().setEncoding("UTF-8");
 				});
 		project.getTasks().withType(JavaCompile.class)
-				.matching(javaCompile -> javaCompile.getName().equals(JavaPlugin.COMPILE_TEST_JAVA_TASK_NAME))
+				.matching(javaCompile -> javaCompile.getName().equals(JavaPlugin.COMPILE_TEST_JAVA_TASK_NAME)
+						|| javaCompile.getName().equals("compileTestFixturesJava"))
 				.forEach(compileTask -> {
 					compileTask.getOptions().setCompilerArgs(TEST_COMPILER_ARGS);
 					compileTask.getOptions().setEncoding("UTF-8");
 				});
 	}
-}
\ No newline at end of file
+
+}
diff --git a/spring-aop/src/testFixtures/java/org/springframework/aop/testfixture/advice/MethodCounter.java b/spring-aop/src/testFixtures/java/org/springframework/aop/testfixture/advice/MethodCounter.java
index 6a703fe23a7..384973bd9aa 100644
--- a/spring-aop/src/testFixtures/java/org/springframework/aop/testfixture/advice/MethodCounter.java
+++ b/spring-aop/src/testFixtures/java/org/springframework/aop/testfixture/advice/MethodCounter.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -25,6 +25,7 @@ import java.util.HashMap;
  *
  * @author Rod Johnson
  * @author Chris Beams
+ * @author Sam Brannen
  */
 @SuppressWarnings("serial")
 public class MethodCounter implements Serializable {
@@ -39,15 +40,12 @@ public class MethodCounter implements Serializable {
 	}
 
 	protected void count(String methodName) {
-		Integer i = map.get(methodName);
-		i = (i != null) ? new Integer(i.intValue() + 1) : new Integer(1);
-		map.put(methodName, i);
+		map.merge(methodName, 1, (n, m) -> n + 1);
 		++allCount;
 	}
 
 	public int getCalls(String methodName) {
-		Integer i = map.get(methodName);
-		return (i != null ? i.intValue() : 0);
+		return map.getOrDefault(methodName, 0);
 	}
 
 	public int getCalls() {
diff --git a/spring-beans/src/testFixtures/java/org/springframework/beans/testfixture/beans/TestBean.java b/spring-beans/src/testFixtures/java/org/springframework/beans/testfixture/beans/TestBean.java
index 10431c03425..ca3850a220a 100644
--- a/spring-beans/src/testFixtures/java/org/springframework/beans/testfixture/beans/TestBean.java
+++ b/spring-beans/src/testFixtures/java/org/springframework/beans/testfixture/beans/TestBean.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -75,7 +75,7 @@ public class TestBean implements BeanNameAware, BeanFactoryAware, ITestBean, IOt
 
 	private Date date = new Date();
 
-	private Float myFloat = new Float(0.0);
+	private Float myFloat = Float.valueOf(0.0f);
 
 	private Collection<? super Object> friends = new LinkedList<>();