Polishing

spring-core/src/main/java/org/springframework/util/ObjectUtils.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.
@@ -132,14 +132,13 @@ public abstract class ObjectUtils {
 	 * @see CollectionUtils#isEmpty(java.util.Collection)
 	 * @see CollectionUtils#isEmpty(java.util.Map)
 	 */
-	@SuppressWarnings("rawtypes")
 	public static boolean isEmpty(@Nullable Object obj) {
 		if (obj == null) {
 			return true;
 		}
 
 		if (obj instanceof Optional) {
-			return !((Optional) obj).isPresent();
+			return !((Optional<?>) obj).isPresent();
 		}
 		if (obj instanceof CharSequence) {
 			return ((CharSequence) obj).length() == 0;
@@ -148,10 +147,10 @@ public abstract class ObjectUtils {
 			return Array.getLength(obj) == 0;
 		}
 		if (obj instanceof Collection) {
-			return ((Collection) obj).isEmpty();
+			return ((Collection<?>) obj).isEmpty();
 		}
 		if (obj instanceof Map) {
-			return ((Map) obj).isEmpty();
+			return ((Map<?, ?>) obj).isEmpty();
 		}
 
 		// else
@@ -611,9 +610,7 @@ public abstract class ObjectUtils {
 		if (obj == null) {
 			return EMPTY_STRING;
 		}
-		String className = obj.getClass().getName();
-		String identityHexString = getIdentityHexString(obj);
-		return className + '@' + identityHexString;
+		return obj.getClass().getName() + "@" + getIdentityHexString(obj);
 	}
 
 	/**

spring-jms/src/main/java/org/springframework/jms/support/converter/MappingJackson2MessageConverter.java

@@ -457,11 +457,11 @@ public class MappingJackson2MessageConverter implements SmartMessageConverter, B
 		}
 		Class<?> mappedClass = this.idClassMappings.get(typeId);
 		if (mappedClass != null) {
-			return this.objectMapper.getTypeFactory().constructType(mappedClass);
+			return this.objectMapper.constructType(mappedClass);
 		}
 		try {
 			Class<?> typeClass = ClassUtils.forName(typeId, this.beanClassLoader);
-			return this.objectMapper.getTypeFactory().constructType(typeClass);
+			return this.objectMapper.constructType(typeClass);
 		}
 		catch (Throwable ex) {
 			throw new MessageConversionException("Failed to resolve type id [" + typeId + "]", ex);

spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.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.
@@ -92,7 +92,7 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 	}
 
 	/**
-	 * Allows sub-classes to add more supported mime types.
+	 * Allows subclasses to add more supported mime types.
 	 * @since 5.2.2
 	 */
 	protected void addSupportedMimeTypes(MimeType... supportedMimeTypes) {
@@ -167,21 +167,6 @@ 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) {
@@ -197,10 +182,6 @@ 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) {
@@ -240,6 +221,11 @@ 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));
 	}
@@ -265,6 +251,22 @@ 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/converter/MappingJackson2MessageConverter.java

@@ -41,6 +41,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.MimeType;
 
 /**
@@ -139,6 +140,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 		}
 	}
 
+
 	@Override
 	protected boolean canConvertFrom(Message<?> message, @Nullable Class<?> targetClass) {
 		if (targetClass == null || !supportsMimeType(message.getHeaders())) {
@@ -210,7 +212,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 		Object payload = message.getPayload();
 		Class<?> view = getSerializationView(conversionHint);
 		try {
-			if (targetClass.isInstance(payload)) {
+			if (ClassUtils.isAssignableValue(targetClass, payload)) {
 				return payload;
 			}
 			else if (payload instanceof byte[]) {
@@ -246,7 +248,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 			Type genericParameterType = param.getNestedGenericParameterType();
 			Class<?> contextClass = param.getContainingClass();
 			Type type = GenericTypeResolver.resolveType(genericParameterType, contextClass);
-			return this.objectMapper.getTypeFactory().constructType(type);
+			return this.objectMapper.constructType(type);
 		}
 		return this.objectMapper.constructType(targetClass);
 	}
@@ -331,7 +333,7 @@ public class MappingJackson2MessageConverter extends AbstractMessageConverter {
 	 * @return the JSON encoding to use (never {@code null})
 	 */
 	protected JsonEncoding getJsonEncoding(@Nullable MimeType contentType) {
-		if (contentType != null && (contentType.getCharset() != null)) {
+		if (contentType != null && contentType.getCharset() != null) {
 			Charset charset = contentType.getCharset();
 			for (JsonEncoding encoding : JsonEncoding.values()) {
 				if (charset.name().equals(encoding.getJavaName())) {

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

@@ -46,6 +46,8 @@ import org.springframework.util.MimeType;
  *
  * @author Arjen Poutsma
  * @since 4.2
+ * @see Marshaller
+ * @see Unmarshaller
  */
 public class MarshallingMessageConverter extends AbstractMessageConverter {
 
@@ -61,7 +63,8 @@ public class MarshallingMessageConverter extends AbstractMessageConverter {
 	 * {@link #setUnmarshaller(Unmarshaller)} to be invoked separately.
 	 */
 	public MarshallingMessageConverter() {
-		this(new MimeType("application", "xml"), new MimeType("text", "xml"), new MimeType("application", "*+xml"));
+		this(new MimeType("application", "xml"), new MimeType("text", "xml"),
+				new MimeType("application", "*+xml"));
 	}
 
 	/**
@@ -160,7 +163,7 @@ public class MarshallingMessageConverter extends AbstractMessageConverter {
 			return new StreamSource(new ByteArrayInputStream((byte[]) payload));
 		}
 		else {
-			return new StreamSource(new StringReader((String) payload));
+			return new StreamSource(new StringReader(payload.toString()));
 		}
 	}
 

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

@@ -120,9 +120,9 @@ public class ProtobufMessageConverter extends AbstractMessageConverter {
 
 	@Override
 	protected boolean canConvertTo(Object payload, @Nullable MessageHeaders headers) {
-		MimeType mimeType = getMimeType(headers);
+		MimeType contentType = getMimeType(headers);
 		return (super.canConvertTo(payload, headers) ||
-				this.protobufFormatSupport != null && this.protobufFormatSupport.supportsWriteOnly(mimeType));
+				this.protobufFormatSupport != null && this.protobufFormatSupport.supportsWriteOnly(contentType));
 	}
 
 	@Override

spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.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.
@@ -48,8 +48,7 @@ public class MappingJackson2MessageConverterTests {
 	@Test
 	public void defaultConstructor() {
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
-		assertThat(converter.getSupportedMimeTypes())
-				.contains(new MimeType("application", "json"));
+		assertThat(converter.getSupportedMimeTypes()).contains(new MimeType("application", "json"));
 		assertThat(converter.getObjectMapper().getDeserializationConfig()
 				.isEnabled(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)).isFalse();
 	}
@@ -76,13 +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);
 
@@ -97,8 +91,8 @@ public class MappingJackson2MessageConverterTests {
 	@Test
 	public void fromMessageUntyped() {
 		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();
 		@SuppressWarnings("unchecked")
 		HashMap<String, Object> actual = (HashMap<String, Object>) converter.fromMessage(message, HashMap.class);
@@ -198,7 +192,7 @@ public class MappingJackson2MessageConverterTests {
 		String payload = "H\u00e9llo W\u00f6rld";
 		Message<?> message = converter.toMessage(payload, headers);
 
-		assertThat(new String((byte[]) message.getPayload(), StandardCharsets.UTF_16BE)).isEqualTo(("\"" + payload + "\""));
+		assertThat(new String((byte[]) message.getPayload(), StandardCharsets.UTF_16BE)).isEqualTo("\"" + payload + "\"");
 		assertThat(message.getHeaders().get(MessageHeaders.CONTENT_TYPE)).isEqualTo(contentType);
 	}
 
@@ -214,7 +208,7 @@ public class MappingJackson2MessageConverterTests {
 		String payload = "H\u00e9llo W\u00f6rld";
 		Message<?> message = converter.toMessage(payload, headers);
 
-		assertThat(message.getPayload()).isEqualTo(("\"" + payload + "\""));
+		assertThat(message.getPayload()).isEqualTo("\"" + payload + "\"");
 		assertThat(message.getHeaders().get(MessageHeaders.CONTENT_TYPE)).isEqualTo(contentType);
 	}
 
@@ -254,9 +248,12 @@ 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/codec/json/AbstractJackson2Decoder.java

@@ -97,7 +97,7 @@ 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.toClass()) &&
 				getObjectMapper().canDeserialize(javaType) && supportsMimeType(mimeType));

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2CodecSupport.java

@@ -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.apache.commons.logging.Log;
 
 import org.springframework.core.GenericTypeResolver;
@@ -111,8 +110,7 @@ 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 2002-2018 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.
@@ -25,7 +25,7 @@ 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

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

@@ -43,7 +43,6 @@ 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;
@@ -377,8 +376,7 @@ 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/client/RestTemplate.java

@@ -21,7 +21,6 @@ import java.lang.reflect.Type;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
@@ -110,8 +109,7 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 		ClassLoader classLoader = RestTemplate.class.getClassLoader();
 		romePresent = ClassUtils.isPresent("com.rometools.rome.feed.WireFeed", classLoader);
 		jaxb2Present = ClassUtils.isPresent("javax.xml.bind.Binder", classLoader);
-		jackson2Present =
-				ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) &&
+		jackson2Present = ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper", classLoader) &&
 				ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator", classLoader);
 		jackson2XmlPresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.xml.XmlMapper", classLoader);
 		jackson2SmilePresent = ClassUtils.isPresent("com.fasterxml.jackson.dataformat.smile.SmileFactory", classLoader);
@@ -918,7 +916,7 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 				HttpHeaders httpHeaders = httpRequest.getHeaders();
 				HttpHeaders requestHeaders = this.requestEntity.getHeaders();
 				if (!requestHeaders.isEmpty()) {
-					requestHeaders.forEach((key, values) -> httpHeaders.put(key, new LinkedList<>(values)));
+					requestHeaders.forEach((key, values) -> httpHeaders.put(key, new ArrayList<>(values)));
 				}
 				if (httpHeaders.getContentLength() < 0) {
 					httpHeaders.setContentLength(0L);
@@ -937,7 +935,7 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 								(GenericHttpMessageConverter<Object>) messageConverter;
 						if (genericConverter.canWrite(requestBodyType, requestBodyClass, requestContentType)) {
 							if (!requestHeaders.isEmpty()) {
-								requestHeaders.forEach((key, values) -> httpHeaders.put(key, new LinkedList<>(values)));
+								requestHeaders.forEach((key, values) -> httpHeaders.put(key, new ArrayList<>(values)));
 							}
 							logBody(requestBody, requestContentType, genericConverter);
 							genericConverter.write(requestBody, requestBodyType, requestContentType, httpRequest);
@@ -946,7 +944,7 @@ public class RestTemplate extends InterceptingHttpAccessor implements RestOperat
 					}
 					else if (messageConverter.canWrite(requestBodyClass, requestContentType)) {
 						if (!requestHeaders.isEmpty()) {
-							requestHeaders.forEach((key, values) -> httpHeaders.put(key, new LinkedList<>(values)));
+							requestHeaders.forEach((key, values) -> httpHeaders.put(key, new ArrayList<>(values)));
 						}
 						logBody(requestBody, requestContentType, messageConverter);
 						((HttpMessageConverter<Object>) messageConverter).write(

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

@@ -32,6 +32,7 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.util.ObjectUtils;
@@ -237,7 +238,7 @@ 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));
 				}
@@ -402,9 +403,8 @@ 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) {
@@ -416,8 +416,7 @@ 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));
@@ -474,9 +473,8 @@ 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());
 	}
 
 
@@ -660,7 +658,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 
 	@Override
 	public UriComponentsBuilder queryParam(String name, @Nullable Collection<?> values) {
-		return queryParam(name, values != null ? values.toArray() : EMPTY_VALUES);
+		return queryParam(name, (CollectionUtils.isEmpty(values) ? EMPTY_VALUES : values.toArray()));
 	}
 
 	/**
@@ -689,7 +687,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 
 	@Override
 	public UriComponentsBuilder replaceQueryParam(String name, @Nullable Collection<?> values) {
-		return replaceQueryParam(name, values != null ? values.toArray() : EMPTY_VALUES);
+		return replaceQueryParam(name, (CollectionUtils.isEmpty(values) ? EMPTY_VALUES : values.toArray()));
 	}
 
 	/**
@@ -778,12 +776,10 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 					scheme("https");
 					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]));

spring-webmvc/src/main/java/org/springframework/web/servlet/view/RedirectView.java

@@ -20,7 +20,6 @@ import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.lang.reflect.Array;
 import java.net.URLEncoder;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -35,6 +34,7 @@ import org.springframework.beans.BeanUtils;
 import org.springframework.http.HttpStatus;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 import org.springframework.web.context.WebApplicationContext;
@@ -456,12 +456,12 @@ public class RedirectView extends AbstractUrlBasedView implements SmartView {
 		boolean first = (targetUrl.toString().indexOf('?') < 0);
 		for (Map.Entry<String, Object> entry : queryProperties(model).entrySet()) {
 			Object rawValue = entry.getValue();
-			Collection<Object> values;
+			Collection<?> values;
 			if (rawValue != null && rawValue.getClass().isArray()) {
-				values = Arrays.asList(ObjectUtils.toObjectArray(rawValue));
+				values = CollectionUtils.arrayToList(rawValue);
 			}
 			else if (rawValue instanceof Collection) {
-				values = ((Collection<Object>) rawValue);
+				values = ((Collection<?>) rawValue);
 			}
 			else {
 				values = Collections.singleton(rawValue);