Polishing

spring-context/src/main/java/org/springframework/scheduling/concurrent/DefaultManagedTaskScheduler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -36,10 +36,11 @@ import org.springframework.lang.Nullable;
  *
  * @author Juergen Hoeller
  * @since 4.0
+ * @see javax.enterprise.concurrent.ManagedScheduledExecutorService
  */
 public class DefaultManagedTaskScheduler extends ConcurrentTaskScheduler implements InitializingBean {
 
-	private JndiLocatorDelegate jndiLocator = new JndiLocatorDelegate();
+	private final JndiLocatorDelegate jndiLocator = new JndiLocatorDelegate();
 
 	@Nullable
 	private String jndiName = "java:comp/DefaultManagedScheduledExecutorService";

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -193,7 +193,7 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	 * @see <a href="https://tools.ietf.org/html/rfc2616#section-2.2">HTTP 1.1, section 2.2</a>
 	 */
 	private void checkToken(String token) {
-		for (int i = 0; i < token.length(); i++ ) {
+		for (int i = 0; i < token.length(); i++) {
 			char ch = token.charAt(i);
 			if (!TOKEN.get(ch)) {
 				throw new IllegalArgumentException("Invalid token character '" + ch + "' in token \"" + token + "\"");
@@ -206,8 +206,7 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 		Assert.hasLength(value, "'value' must not be empty");
 		checkToken(attribute);
 		if (PARAM_CHARSET.equals(attribute)) {
-			value = unquote(value);
-			Charset.forName(value);
+			Charset.forName(unquote(value));
 		}
 		else if (!isQuotedString(value)) {
 			checkToken(value);
@@ -401,7 +400,7 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	/**
 	 * Determine if the parameters in this {@code MimeType} and the supplied
 	 * {@code MimeType} are equal, performing case-insensitive comparisons
-	 * for {@link Charset}s.
+	 * for {@link Charset Charsets}.
 	 * @since 4.2
 	 */
 	private boolean parametersAreEqual(MimeType other) {
@@ -542,6 +541,11 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	}
 
 
+	/**
+	 * Comparator to sort {@link MimeType MimeTypes} in order of specificity.
+	 *
+	 * @param <T> the type of mime types that may be compared by this comparator
+	 */
 	public static class SpecificityComparator<T extends MimeType> implements Comparator<T> {
 
 		@Override

spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -151,21 +151,6 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 	}
 
 
-	/**
-	 * Returns the default content type for the payload. Called when
-	 * {@link #toMessage(Object, MessageHeaders)} is invoked without message headers or
-	 * without a content type header.
-	 * <p>By default, this returns the first element of the {@link #getSupportedMimeTypes()
-	 * supportedMimeTypes}, if any. Can be overridden in sub-classes.
-	 * @param payload the payload being converted to message
-	 * @return the content type, or {@code null} if not known
-	 */
-	@Nullable
-	protected MimeType getDefaultContentType(Object payload) {
-		List<MimeType> mimeTypes = getSupportedMimeTypes();
-		return (!mimeTypes.isEmpty() ? mimeTypes.get(0) : null);
-	}
-
 	@Override
 	@Nullable
 	public final Object fromMessage(Message<?> message, Class<?> targetClass) {
@@ -181,10 +166,6 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return convertFromInternal(message, targetClass, conversionHint);
 	}
 
-	protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
-		return (supports(targetClass) && supportsMimeType(message.getHeaders()));
-	}
-
 	@Override
 	@Nullable
 	public final Message<?> toMessage(Object payload, @Nullable MessageHeaders headers) {
@@ -224,6 +205,11 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return builder.build();
 	}
 
+
+	protected boolean canConvertFrom(Message<?> message, Class<?> targetClass) {
+		return (supports(targetClass) && supportsMimeType(message.getHeaders()));
+	}
+
 	protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers) {
 		return (supports(payload.getClass()) && supportsMimeType(headers));
 	}
@@ -249,6 +235,22 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 		return (headers != null && this.contentTypeResolver != null ? this.contentTypeResolver.resolve(headers) : null);
 	}
 
+	/**
+	 * Return the default content type for the payload. Called when
+	 * {@link #toMessage(Object, MessageHeaders)} is invoked without
+	 * message headers or without a content type header.
+	 * <p>By default, this returns the first element of the
+	 * {@link #getSupportedMimeTypes() supportedMimeTypes}, if any.
+	 * Can be overridden in subclasses.
+	 * @param payload the payload being converted to a message
+	 * @return the content type, or {@code null} if not known
+	 */
+	@Nullable
+	protected MimeType getDefaultContentType(Object payload) {
+		List<MimeType> mimeTypes = getSupportedMimeTypes();
+		return (!mimeTypes.isEmpty() ? mimeTypes.get(0) : null);
+	}
+
 
 	/**
 	 * Whether the given class is supported by this converter.

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -684,8 +684,10 @@ public class DefaultStompSession implements ConnectionHandlingStompSession {
 			if (conn != null) {
 				conn.send(HEARTBEAT).addCallback(
 						new ListenableFutureCallback<Void>() {
+							@Override
 							public void onSuccess(@Nullable Void result) {
 							}
+							@Override
 							public void onFailure(Throwable ex) {
 								handleFailure(ex);
 							}

spring-messaging/src/main/java/org/springframework/messaging/support/NativeMessageHeaderAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -53,14 +53,14 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 
 
 	/**
-	 * A protected constructor to create new headers.
+	 * Protected constructor to create a new instance.
 	 */
 	protected NativeMessageHeaderAccessor() {
 		this((Map<String, List<String>>) null);
 	}
 
 	/**
-	 * A protected constructor to create new headers.
+	 * Protected constructor to create an instance with the given native headers.
 	 * @param nativeHeaders native headers to create the message with (may be {@code null})
 	 */
 	protected NativeMessageHeaderAccessor(@Nullable Map<String, List<String>> nativeHeaders) {
@@ -70,7 +70,7 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 	}
 
 	/**
-	 * A protected constructor accepting the headers of an existing message to copy.
+	 * Protected constructor that copies headers from another message.
 	 */
 	protected NativeMessageHeaderAccessor(@Nullable Message<?> message) {
 		super(message);
@@ -85,6 +85,10 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 		}
 	}
 
+
+	/**
+	 * Subclasses can use this method to access the "native" headers sub-map.
+	 */
 	@SuppressWarnings("unchecked")
 	@Nullable
 	protected Map<String, List<String>> getNativeHeaders() {
@@ -92,7 +96,7 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 	}
 
 	/**
-	 * Return a copy of the native header values or an empty map.
+	 * Return a copy of the native headers sub-map, or an empty map.
 	 */
 	public Map<String, List<String>> toNativeHeaderMap() {
 		Map<String, List<String>> map = getNativeHeaders();
@@ -114,6 +118,7 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 
 	/**
 	 * Whether the native header map contains the give header name.
+	 * @param headerName the name of the header
 	 */
 	public boolean containsNativeHeader(String headerName) {
 		Map<String, List<String>> map = getNativeHeaders();
@@ -121,8 +126,9 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 	}
 
 	/**
-	 * Return all values for the specified native header.
-	 * or {@code null} if none.
+	 * Return all values for the specified native header, if present.
+	 * @param headerName the name of the header
+	 * @return the associated values, or {@code null} if none
 	 */
 	@Nullable
 	public List<String> getNativeHeader(String headerName) {
@@ -131,15 +137,16 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 	}
 
 	/**
-	 * Return the first value for the specified native header,
-	 * or {@code null} if none.
+	 * Return the first value for the specified native header, if present.
+	 * @param headerName the name of the header
+	 * @return the associated value, or {@code null} if none
 	 */
 	@Nullable
 	public String getFirstNativeHeader(String headerName) {
 		Map<String, List<String>> map = getNativeHeaders();
 		if (map != null) {
 			List<String> values = map.get(headerName);
-			if (values != null) {
+			if (!CollectionUtils.isEmpty(values)) {
 				return values.get(0);
 			}
 		}
@@ -148,6 +155,8 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 
 	/**
 	 * Set the specified native header value replacing existing values.
+	 * <p>In order for this to work, the accessor must be {@link #isMutable()
+	 * mutable}. See {@link MessageHeaderAccessor} for details.
 	 */
 	public void setNativeHeader(String name, @Nullable String value) {
 		Assert.state(isMutable(), "Already immutable");
@@ -173,6 +182,10 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 
 	/**
 	 * Add the specified native header value to existing values.
+	 * <p>In order for this to work, the accessor must be {@link #isMutable()
+	 * mutable}. See {@link MessageHeaderAccessor} for details.
+	 * @param name the name of the header
+	 * @param value the header value to set
 	 */
 	public void addNativeHeader(String name, @Nullable String value) {
 		Assert.state(isMutable(), "Already immutable");
@@ -189,6 +202,10 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 		setModified(true);
 	}
 
+	/**
+	 * Add the specified native headers to existing values.
+	 * @param headers the headers to set
+	 */
 	public void addNativeHeaders(@Nullable MultiValueMap<String, String> headers) {
 		if (headers == null) {
 			return;
@@ -196,23 +213,38 @@ public class NativeMessageHeaderAccessor extends MessageHeaderAccessor {
 		headers.forEach((key, values) -> values.forEach(value -> addNativeHeader(key, value)));
 	}
 
+	/**
+	 * Remove the specified native header value replacing existing values.
+	 * <p>In order for this to work, the accessor must be {@link #isMutable()
+	 * mutable}. See {@link MessageHeaderAccessor} for details.
+	 * @param headerName the name of the header
+	 * @return the associated values, or {@code null} if the header was not present
+	 */
 	@Nullable
-	public List<String> removeNativeHeader(String name) {
+	public List<String> removeNativeHeader(String headerName) {
 		Assert.state(isMutable(), "Already immutable");
 		Map<String, List<String>> nativeHeaders = getNativeHeaders();
-		if (nativeHeaders == null) {
+		if (CollectionUtils.isEmpty(nativeHeaders)) {
 			return null;
 		}
-		return nativeHeaders.remove(name);
+		return nativeHeaders.remove(headerName);
 	}
 
+
+	/**
+	 * Return the first value for the specified native header,
+	 * or {@code null} if none.
+	 * @param headerName the name of the header
+	 * @param headers the headers map to introspect
+	 * @return the associated value, or {@code null} if none
+	 */
 	@SuppressWarnings("unchecked")
 	@Nullable
 	public static String getFirstNativeHeader(String headerName, Map<String, Object> headers) {
 		Map<String, List<String>> map = (Map<String, List<String>>) headers.get(NATIVE_HEADERS);
 		if (map != null) {
 			List<String> values = map.get(headerName);
-			if (values != null) {
+			if (!CollectionUtils.isEmpty(values)) {
 				return values.get(0);
 			}
 		}

spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -75,13 +75,8 @@ public class MappingJackson2MessageConverterTests {
 	@Test
 	public void fromMessage() {
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
-		String payload = "{" +
-				"\"bytes\":\"AQI=\"," +
-				"\"array\":[\"Foo\",\"Bar\"]," +
-				"\"number\":42," +
-				"\"string\":\"Foo\"," +
-				"\"bool\":true," +
-				"\"fraction\":42.0}";
+		String payload = "{\"bytes\":\"AQI=\",\"array\":[\"Foo\",\"Bar\"]," +
+				"\"number\":42,\"string\":\"Foo\",\"bool\":true,\"fraction\":42.0}";
 		Message<?> message = MessageBuilder.withPayload(payload.getBytes(StandardCharsets.UTF_8)).build();
 		MyBean actual = (MyBean) converter.fromMessage(message, MyBean.class);
 
@@ -245,9 +240,12 @@ public class MappingJackson2MessageConverterTests {
 	public void jsonViewPayload(@JsonView(MyJacksonView2.class) JacksonViewBean payload) {
 	}
 
-	void handleList(List<Long> payload) {}
+	void handleList(List<Long> payload) {
+	}
+
+	void handleMessage(Message<MyBean> message) {
+	}
 
-	void handleMessage(Message<MyBean> message) {}
 
 	public static class MyBean {
 

spring-web/src/main/java/org/springframework/http/ResponseCookie.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -144,7 +144,6 @@ public final class ResponseCookie extends HttpCookie {
 			long millis = this.maxAge.getSeconds() > 0 ? System.currentTimeMillis() + this.maxAge.toMillis() : 0;
 			sb.append(HttpHeaders.formatDate(millis));
 		}
-
 		if (this.secure) {
 			sb.append("; Secure");
 		}
@@ -160,7 +159,7 @@ public final class ResponseCookie extends HttpCookie {
 	 * with a name-value pair and may also include attributes.
 	 * @param name the cookie name
 	 * @param value the cookie value
-	 * @return the created cookie instance
+	 * @return a builder to create the cookie with
 	 */
 	public static ResponseCookieBuilder from(final String name, final String value) {
 

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Decoder.java

@@ -74,7 +74,7 @@ public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport imple
 
 	@Override
 	public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
-		JavaType javaType = getObjectMapper().getTypeFactory().constructType(elementType.getType());
+		JavaType javaType = getObjectMapper().constructType(elementType.getType());
 		// Skip String: CharSequenceDecoder + "*/*" comes after
 		return (!CharSequence.class.isAssignableFrom(elementType.resolve(Object.class)) &&
 				getObjectMapper().canDeserialize(javaType) && supportsMimeType(mimeType));

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2CodecSupport.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.
@@ -27,7 +27,6 @@ import java.util.Map;
 import com.fasterxml.jackson.annotation.JsonView;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.fasterxml.jackson.databind.type.TypeFactory;
 
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.core.MethodParameter;
@@ -95,8 +94,7 @@ public abstract class Jackson2CodecSupport {
 	}
 
 	protected JavaType getJavaType(Type type, @Nullable Class<?> contextClass) {
-		TypeFactory typeFactory = this.objectMapper.getTypeFactory();
-		return typeFactory.constructType(GenericTypeResolver.resolveType(type, contextClass));
+		return this.objectMapper.constructType(GenericTypeResolver.resolveType(type, contextClass));
 	}
 
 	protected Map<String, Object> getHints(ResolvableType resolvableType) {

spring-web/src/main/java/org/springframework/http/converter/HttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -25,11 +25,12 @@ import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
 
 /**
- * Strategy interface that specifies a converter that can convert from and to HTTP requests and responses.
+ * Strategy interface for converting from and to HTTP requests and responses.
  *
  * @author Arjen Poutsma
  * @author Juergen Hoeller
  * @since 3.0
+ * @param <T> the converted object type
  */
 public interface HttpMessageConverter<T> {
 
@@ -53,7 +54,7 @@ public interface HttpMessageConverter<T> {
 
 	/**
 	 * Return the list of {@link MediaType} objects supported by this converter.
-	 * @return the list of supported media types
+	 * @return the list of supported media types, potentially an immutable copy
 	 */
 	List<MediaType> getSupportedMediaTypes();
 

spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java

@@ -38,7 +38,6 @@ import com.fasterxml.jackson.databind.SerializationConfig;
 import com.fasterxml.jackson.databind.SerializationFeature;
 import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
 import com.fasterxml.jackson.databind.ser.FilterProvider;
-import com.fasterxml.jackson.databind.type.TypeFactory;
 
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.http.HttpInputMessage;
@@ -319,8 +318,7 @@ public abstract class AbstractJackson2HttpMessageConverter extends AbstractGener
 	 * @return the Jackson JavaType
 	 */
 	protected JavaType getJavaType(Type type, @Nullable Class<?> contextClass) {
-		TypeFactory typeFactory = this.objectMapper.getTypeFactory();
-		return typeFactory.constructType(GenericTypeResolver.resolveType(type, contextClass));
+		return this.objectMapper.constructType(GenericTypeResolver.resolveType(type, contextClass));
 	}
 
 	/**

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

@@ -233,7 +233,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 			}
 			builder.scheme(scheme);
 			if (opaque) {
-				String ssp = uri.substring(scheme.length()).substring(1);
+				String ssp = uri.substring(scheme.length() + 1);
 				if (StringUtils.hasLength(fragment)) {
 					ssp = ssp.substring(0, ssp.length() - (fragment.length() + 1));
 				}
@@ -394,9 +394,8 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 	 * characters that should have been encoded.
 	 */
 	public UriComponents build(boolean encoded) {
-		return buildInternal(encoded ?
-				EncodingHint.FULLY_ENCODED :
-				this.encodeTemplate ? EncodingHint.ENCODE_TEMPLATE : EncodingHint.NONE);
+		return buildInternal(encoded ? EncodingHint.FULLY_ENCODED :
+				(this.encodeTemplate ? EncodingHint.ENCODE_TEMPLATE : EncodingHint.NONE));
 	}
 
 	private UriComponents buildInternal(EncodingHint hint) {
@@ -408,8 +407,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 			HierarchicalUriComponents uric = new HierarchicalUriComponents(this.scheme, this.fragment,
 					this.userInfo, this.host, this.port, this.pathBuilder.build(), this.queryParams,
 					hint == EncodingHint.FULLY_ENCODED);
-
-			result = hint == EncodingHint.ENCODE_TEMPLATE ? uric.encodeTemplate(this.charset) : uric;
+			result = (hint == EncodingHint.ENCODE_TEMPLATE ? uric.encodeTemplate(this.charset) : uric);
 		}
 		if (!this.uriVariables.isEmpty()) {
 			result = result.expand(name -> this.uriVariables.getOrDefault(name, UriTemplateVariables.SKIP_VALUE));
@@ -466,9 +464,8 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 	 * @see UriComponents#toUriString()
 	 */
 	public String toUriString() {
-		return this.uriVariables.isEmpty() ?
-				build().encode().toUriString() :
-				buildInternal(EncodingHint.ENCODE_TEMPLATE).toUriString();
+		return (this.uriVariables.isEmpty() ? build().encode().toUriString() :
+				buildInternal(EncodingHint.ENCODE_TEMPLATE).toUriString());
 	}
 
 
@@ -841,12 +838,10 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 					scheme(StringUtils.tokenizeToStringArray(protocolHeader, ",")[0]);
 					port(null);
 				}
-
 				String hostHeader = headers.getFirst("X-Forwarded-Host");
 				if (StringUtils.hasText(hostHeader)) {
 					adaptForwardedHost(StringUtils.tokenizeToStringArray(hostHeader, ",")[0]);
 				}
-
 				String portHeader = headers.getFirst("X-Forwarded-Port");
 				if (StringUtils.hasText(portHeader)) {
 					port(Integer.parseInt(StringUtils.tokenizeToStringArray(portHeader, ",")[0]));