Merge branch '5.1.x'

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -119,21 +119,21 @@ public class ServerSentEventHttpMessageReader implements HttpMessageReader<Objec
 		for (String line : lines) {
 			if (line.startsWith("data:")) {
 				data = (data != null ? data : new StringBuilder());
-				data.append(line.substring(5)).append("\n");
+				data.append(line.substring(5).trim()).append("\n");
 			}
 			if (shouldWrap) {
 				if (line.startsWith("id:")) {
-					sseBuilder.id(line.substring(3));
+					sseBuilder.id(line.substring(3).trim());
 				}
 				else if (line.startsWith("event:")) {
-					sseBuilder.event(line.substring(6));
+					sseBuilder.event(line.substring(6).trim());
 				}
 				else if (line.startsWith("retry:")) {
-					sseBuilder.retry(Duration.ofMillis(Long.valueOf(line.substring(6))));
+					sseBuilder.retry(Duration.ofMillis(Long.valueOf(line.substring(6).trim())));
 				}
 				else if (line.startsWith(":")) {
 					comment = (comment != null ? comment : new StringBuilder());
-					comment.append(line.substring(1)).append("\n");
+					comment.append(line.substring(1).trim()).append("\n");
 				}
 			}
 		}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -113,7 +113,7 @@ public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport imple
 				getObjectMapper().readerWithView(jsonView).forType(javaType) :
 				getObjectMapper().readerFor(javaType));
 
-		return tokens.map(tokenBuffer -> {
+		return tokens.flatMap(tokenBuffer -> {
 			try {
 				Object value = reader.readValue(tokenBuffer.asParser(getObjectMapper()));
 				if (!Hints.isLoggingSuppressed(hints)) {
@@ -122,16 +122,16 @@ public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport imple
 						return Hints.getLogPrefix(hints) + "Decoded [" + formatted + "]";
 					});
 				}
-				return value;
+				return Mono.justOrEmpty(value);
 			}
 			catch (InvalidDefinitionException ex) {
-				throw new CodecException("Type definition error: " + ex.getType(), ex);
+				return Mono.error(new CodecException("Type definition error: " + ex.getType(), ex));
 			}
 			catch (JsonProcessingException ex) {
-				throw new DecodingException("JSON decoding error: " + ex.getOriginalMessage(), ex);
+				return Mono.error(new DecodingException("JSON decoding error: " + ex.getOriginalMessage(), ex));
 			}
 			catch (IOException ex) {
-				throw new DecodingException("I/O error while parsing input stream", ex);
+				return Mono.error(new DecodingException("I/O error while parsing input stream", ex));
 			}
 		});
 	}

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -77,7 +77,8 @@ import org.springframework.web.util.UriTemplateHandler;
  * modern alternative to the {@code RestTemplate} with efficient support for
  * both sync and async, as well as streaming scenarios. The {@code RestTemplate}
  * will be deprecated in a future version and will not have major new features
- * added going forward.
+ * added going forward. See the WebClient section of the Spring Framework reference
+ * documentation for more details and example code.
  *
  * @author Arjen Poutsma
  * @author Brian Clozel

spring-web/src/test/java/org/springframework/http/codec/json/Jackson2JsonDecoderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -38,6 +38,7 @@ import org.springframework.core.codec.AbstractDecoderTestCase;
 import org.springframework.core.codec.CodecException;
 import org.springframework.core.codec.DecodingException;
 import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.http.MediaType;
 import org.springframework.http.codec.Pojo;
 import org.springframework.util.MimeType;
 
@@ -174,6 +175,14 @@ public class Jackson2JsonDecoderTests extends AbstractDecoderTestCase<Jackson2Js
 				.verifyError(DecodingException.class));
 	}
 
+	@Test // #22042
+	public void decodeWithNullLiteral() {
+		Flux<Object> result = this.decoder.decode(Flux.concat(stringBuffer("null")),
+				ResolvableType.forType(Pojo.class), MediaType.APPLICATION_JSON, Collections.emptyMap());
+
+		StepVerifier.create(result).expectComplete().verify();
+	}
+
 	@Test
 	public void noDefaultConstructor() {
 		Flux<DataBuffer> input =

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -25,6 +25,7 @@ import org.apache.commons.logging.LogFactory;
 
 import org.springframework.core.Ordered;
 import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
 import org.springframework.web.servlet.HandlerExceptionResolver;
 import org.springframework.web.servlet.ModelAndView;
 
@@ -99,14 +100,16 @@ public abstract class AbstractHandlerExceptionResolver implements HandlerExcepti
 	/**
 	 * Set the log category for warn logging. The name will be passed to the underlying logger
 	 * implementation through Commons Logging, getting interpreted as a log category according
-	 * to the logger's configuration.
-	 * <p>Default is no warn logging. Specify this setting to activate warn logging into a specific
+	 * to the logger's configuration. If {@code null} is passed, warn logging is turned off.
+	 * <p>By default there is no warn logging although sub-classes like
+	 * {@link org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver}
+	 * can change that default. Specify this setting to activate warn logging into a specific
 	 * category. Alternatively, override the {@link #logException} method for custom logging.
 	 * @see org.apache.commons.logging.LogFactory#getLog(String)
 	 * @see java.util.logging.Logger#getLogger(String)
 	 */
 	public void setWarnLogCategory(String loggerName) {
-		this.warnLogger = LogFactory.getLog(loggerName);
+		this.warnLogger = !StringUtils.isEmpty(loggerName) ? LogFactory.getLog(loggerName) : null;
 	}
 
 	/**

src/docs/asciidoc/web/webflux-webclient.adoc

@@ -541,6 +541,58 @@ WebClient client = webClient.mutate()
 
 
 
+[[webflux-client-synchronous]]
+== Synchronous Use
+
+`WebClient` can be used in synchronous style by blocking at the end for the result:
+
+[source,java,intent=0]
+[subs="verbatim,quotes"]
+----
+Person person = client.get().uri("/person/{id}", i).retrieve()
+	.bodyToMono(Person.class)
+	.block();
+
+List<Person> persons = client.get().uri("/persons").retrieve()
+	.bodyToFlux(Person.class)
+	.collectList()
+	.block();
+----
+
+However if multiple calls need to be made, it's more efficient to avoid blocking on each
+response individually, and instead wait for the combined result:
+
+[source,java,intent=0]
+[subs="verbatim,quotes"]
+----
+Mono<Person> personMono = client.get().uri("/person/{id}", personId)
+		.retrieve().bodyToMono(Person.class);
+
+Mono<List<Hobby>> hobbiesMono = client.get().uri("/person/{id}/hobbies", personId)
+		.retrieve().bodyToFlux(Hobby.class).collectList();
+
+Map<String, Object> data = Mono.zip(personMono, hobbiesMono, (person, hobbies) -> {
+			Map<String, String> map = new LinkedHashMap<>();
+			map.put("person", personName);
+			map.put("hobbies", hobbies);
+			return map;
+		})
+		.block();
+----
+
+The above is merely one example. There are lots of other patterns and operators for putting
+together a reactive pipeline that makes many remote calls, potentially some nested,
+inter-dependent, without ever blocking until the end.
+
+[NOTE]
+====
+You should never have to block in a Spring MVC controller. Simply return the resulting
+`Flux` or `Mono` from the controller method.
+====
+
+
+
+
 [[webflux-client-testing]]
 == Testing
 

src/docs/asciidoc/web/webmvc-client.adoc

@@ -14,9 +14,11 @@ Spring REST client and exposes a simple, template-method API over underlying HTT
 libraries.
 
 NOTE: As of 5.0, the non-blocking, reactive `WebClient` offers a modern alternative to the
-`RestTemplate`, with efficient support for both synchronous and asynchronous, as well as streaming
-scenarios. The `RestTemplate` will be deprecated in a future version and will not have
-major new features added going forward.
+`RestTemplate`, with efficient support for both
+<<web-reactive.adoc#webflux-client-synchronous,synchronous and asynchronous>>, as well as
+streaming scenarios. The `RestTemplate` will be deprecated in a future version and will
+not have major new features added going forward.
+
 
 See <<integration.adoc#rest-client-access,REST Endpoints>> for details.