Polishing (backported from master)

Author: jhoeller

spring-context/src/main/java/org/springframework/ui/ConcurrentModel.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -66,7 +66,8 @@ public ConcurrentModel(Object attributeValue) {
 
 
 	@Override
-	public Object put(String key, Object value) {
+	@Nullable
+	public Object put(String key, @Nullable Object value) {
 		if (value != null) {
 			return super.put(key, value);
 		}

spring-core/src/main/java/org/springframework/util/ConcurrentReferenceHashMap.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -299,7 +299,7 @@ protected V execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> entry,
 
 	@Override
 	@Nullable
-	public V remove(Object key) {
+	public V remove(@Nullable Object key) {
 		return doTask(key, new Task<V>(TaskOption.RESTRUCTURE_AFTER, TaskOption.SKIP_IF_EMPTY) {
 			@Override
 			@Nullable
@@ -316,7 +316,7 @@ protected V execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> entry)
 	}
 
 	@Override
-	public boolean remove(Object key, final Object value) {
+	public boolean remove(@Nullable Object key, final @Nullable Object value) {
 		Boolean result = doTask(key, new Task<Boolean>(TaskOption.RESTRUCTURE_AFTER, TaskOption.SKIP_IF_EMPTY) {
 			@Override
 			protected Boolean execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> entry) {
@@ -333,7 +333,7 @@ protected Boolean execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> e
 	}
 
 	@Override
-	public boolean replace(K key, final V oldValue, final V newValue) {
+	public boolean replace(@Nullable K key, final @Nullable V oldValue, final @Nullable V newValue) {
 		Boolean result = doTask(key, new Task<Boolean>(TaskOption.RESTRUCTURE_BEFORE, TaskOption.SKIP_IF_EMPTY) {
 			@Override
 			protected Boolean execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> entry) {
@@ -349,7 +349,7 @@ protected Boolean execute(@Nullable Reference<K, V> ref, @Nullable Entry<K, V> e
 
 	@Override
 	@Nullable
-	public V replace(K key, final V value) {
+	public V replace(@Nullable K key, final @Nullable V value) {
 		return doTask(key, new Task<V>(TaskOption.RESTRUCTURE_BEFORE, TaskOption.SKIP_IF_EMPTY) {
 			@Override
 			@Nullable
@@ -474,7 +474,7 @@ protected final class Segment extends ReentrantLock {
 		 * The total number of references contained in this segment. This includes chained
 		 * references and references that have been garbage collected but not purged.
 		 */
-		private final AtomicInteger count = new AtomicInteger(0);
+		private final AtomicInteger count = new AtomicInteger();
 
 		/**
 		 * The threshold when resizing of the references should occur. When {@code count}

spring-core/src/main/java/org/springframework/util/PropertyPlaceholderHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -28,9 +28,11 @@
 import org.springframework.lang.Nullable;
 
 /**
- * Utility class for working with Strings that have placeholder values in them. A placeholder takes the form
- * {@code ${name}}. Using {@code PropertyPlaceholderHelper} these placeholders can be substituted for
- * user-supplied values. <p> Values for substitution can be supplied using a {@link Properties} instance or
+ * Utility class for working with Strings that have placeholder values in them.
+ * A placeholder takes the form {@code ${name}}. Using {@code PropertyPlaceholderHelper}
+ * these placeholders can be substituted for user-supplied values.
+ *
+ * <p>Values for substitution can be supplied using a {@link Properties} instance or
  * using a {@link PlaceholderResolver}.
  *
  * @author Juergen Hoeller

spring-web/src/test/java/org/springframework/http/converter/json/JsonbHttpMessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -72,7 +72,7 @@ public void canReadAndWriteMicroformats() {
 	public void readTyped() throws IOException {
 		String body = "{\"bytes\":[1,2],\"array\":[\"Foo\",\"Bar\"]," +
 				"\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
-		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes("UTF-8"));
+		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes(StandardCharsets.UTF_8));
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
 		MyBean result = (MyBean) this.converter.read(MyBean.class, inputMessage);
 
@@ -90,7 +90,7 @@ public void readTyped() throws IOException {
 	public void readUntyped() throws IOException {
 		String body = "{\"bytes\":[1,2],\"array\":[\"Foo\",\"Bar\"]," +
 				"\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
-		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes("UTF-8"));
+		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes(StandardCharsets.UTF_8));
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
 		HashMap<String, Object> result = (HashMap<String, Object>) this.converter.read(HashMap.class, inputMessage);
 		assertThat(result.get("string")).isEqualTo("Foo");
@@ -167,9 +167,9 @@ public void writeUTF16() throws IOException {
 	}
 
 	@Test
-	public void readInvalidJson() throws IOException {
+	public void readInvalidJson() {
 		String body = "FooBar";
-		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes("UTF-8"));
+		MockHttpInputMessage inputMessage = new MockHttpInputMessage(body.getBytes(StandardCharsets.UTF_8));
 		inputMessage.getHeaders().setContentType(new MediaType("application", "json"));
 		assertThatExceptionOfType(HttpMessageNotReadableException.class).isThrownBy(() ->
 				this.converter.read(MyBean.class, inputMessage));

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/HandlerMappingIntrospector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -89,7 +89,7 @@ public HandlerMappingIntrospector(ApplicationContext context) {
 
 
 	/**
-	 * Return the configured HandlerMapping's.
+	 * Return the configured or detected {@code HandlerMapping}s.
 	 */
 	public List<HandlerMapping> getHandlerMappings() {
 		return (this.handlerMappings != null ? this.handlerMappings : Collections.emptyList());