Avoid java.util.Optional signatures for simple field access

Issue: SPR-15576

Author: jhoeller

spring-core/src/main/java/org/springframework/core/ReactiveAdapter.java

@@ -16,7 +16,6 @@
 
 package org.springframework.core;
 
-import java.util.Optional;
 import java.util.function.Function;
 
 import org.reactivestreams.Publisher;
@@ -106,7 +105,6 @@ public boolean isNoValue() {
 	 */
 	@SuppressWarnings("unchecked")
 	public <T> Publisher<T> toPublisher(Object source) {
-		source = (source instanceof Optional ? ((Optional<?>) source).orElse(null) : source);
 		if (source == null) {
 			source = getDescriptor().getEmptyValue();
 		}

spring-test/src/main/java/org/springframework/mock/http/server/reactive/MockServerHttpRequest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.mock.http.server.reactive;
 
 import java.net.InetSocketAddress;
@@ -22,7 +23,6 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Optional;
 
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
@@ -89,8 +89,8 @@ public String getContextPath() {
 	}
 
 	@Override
-	public Optional<InetSocketAddress> getRemoteAddress() {
-		return Optional.ofNullable(this.remoteAddress);
+	public InetSocketAddress getRemoteAddress() {
+		return this.remoteAddress;
 	}
 
 	@Override

spring-test/src/main/java/org/springframework/test/web/reactive/server/DefaultControllerSpec.java

@@ -19,7 +19,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Optional;
 import java.util.function.Consumer;
 
 import org.springframework.context.ApplicationContext;
@@ -199,8 +198,8 @@ public void addFormatters(FormatterRegistry registry) {
 		}
 
 		@Override
-		public Optional<Validator> getValidator() {
-			return Optional.ofNullable(this.validator);
+		public Validator getValidator() {
+			return this.validator;
 		}
 
 		@Override

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

@@ -17,13 +17,12 @@
 package org.springframework.http;
 
 import java.time.Duration;
-import java.util.Optional;
 
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 
 /**
- * An {@code HttpCookie} sub-class with the additional attributes allowed in
+ * An {@code HttpCookie} subclass with the additional attributes allowed in
  * the "Set-Cookie" response header. To build an instance use the {@link #from}
  * static method.
  *
@@ -35,9 +34,9 @@ public final class ResponseCookie extends HttpCookie {
 
 	private final Duration maxAge;
 
-	private final Optional<String> domain;
+	private final String domain;
 
-	private final Optional<String> path;
+	private final String path;
 
 	private final boolean secure;
 
@@ -53,8 +52,8 @@ private ResponseCookie(String name, String value, Duration maxAge, String domain
 		super(name, value);
 		Assert.notNull(maxAge, "Max age must not be null");
 		this.maxAge = maxAge;
-		this.domain = Optional.ofNullable(domain);
-		this.path = Optional.ofNullable(path);
+		this.domain = domain;
+		this.path = path;
 		this.secure = secure;
 		this.httpOnly = httpOnly;
 	}
@@ -72,16 +71,16 @@ public Duration getMaxAge() {
 	}
 
 	/**
-	 * Return the cookie "Domain" attribute.
+	 * Return the cookie "Domain" attribute, or {@code null} if not set.
 	 */
-	public Optional<String> getDomain() {
+	public String getDomain() {
 		return this.domain;
 	}
 
 	/**
-	 * Return the cookie "Path" attribute.
+	 * Return the cookie "Path" attribute, or {@code null} if not set.
 	 */
-	public Optional<String> getPath() {
+	public String getPath() {
 		return this.path;
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -17,21 +17,21 @@
 package org.springframework.http.codec;
 
 import java.time.Duration;
-import java.util.Optional;
 
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 
 /**
- * Representation for a Server-Sent Event for use with Spring's reactive Web
- * support. {@code Flux<ServerSentEvent>} or {@code Observable<ServerSentEvent>} is the
+ * Representation for a Server-Sent Event for use with Spring's reactive Web support.
+ * {@code Flux<ServerSentEvent>} or {@code Observable<ServerSentEvent>} is the
  * reactive equivalent to Spring MVC's {@code SseEmitter}.
  *
  * @param <T> the type of data that this event contains
+ *
  * @author Sebastien Deleuze
  * @author Arjen Poutsma
+ * @since 5.0
  * @see ServerSentEventHttpMessageWriter
  * @see <a href="https://www.w3.org/TR/eventsource/">Server-Sent Events W3C recommendation</a>
- * @since 5.0
  */
 public class ServerSentEvent<T> {
 
@@ -54,68 +54,69 @@ private ServerSentEvent(String id, String event, T data, Duration retry, String
         this.comment = comment;
     }
 
-    /**
-     * Return a builder for a {@code SseEvent}.
-     *
-     * @param <T> the type of data that this event contains
-     * @return the builder
-     */
-    public static <T> Builder<T> builder() {
-        return new BuilderImpl<>();
-    }
-
-    /**
-     * Return a builder for a {@code SseEvent}, populated with the give {@linkplain #data() data}.
-     *
-     * @param <T> the type of data that this event contains
-     * @return the builder
-     */
-    public static <T> Builder<T> builder(T data) {
-        return new BuilderImpl<>(data);
-    }
 
     /**
      * Return the {@code id} field of this event, if available.
      */
-    public Optional<String> id() {
-        return Optional.ofNullable(this.id);
+    public String id() {
+        return this.id;
     }
 
     /**
      * Return the {@code event} field of this event, if available.
      */
-    public Optional<String> event() {
-        return Optional.ofNullable(this.event);
+    public String event() {
+        return this.event;
     }
 
     /**
      * Return the {@code data} field of this event, if available.
      */
-    public Optional<T> data() {
-        return Optional.ofNullable(this.data);
+    public T data() {
+        return this.data;
     }
 
     /**
      * Return the {@code retry} field of this event, if available.
      */
-    public Optional<Duration> retry() {
-        return Optional.ofNullable(this.retry);
+    public Duration retry() {
+        return this.retry;
     }
 
     /**
      * Return the comment of this event, if available.
      */
-    public Optional<String> comment() {
-        return Optional.ofNullable(this.comment);
+    public String comment() {
+        return this.comment;
     }
 
+
     @Override
     public String toString() {
-        return "ServerSentEvent [id = '" + id + '\'' + ", event='" + event + '\'' +
-                ", data=" + data + ", retry=" + retry + ", comment='" + comment + '\'' +
-                ']';
+        return ("ServerSentEvent [id = '" + this.id + '\'' + ", event='" + this.event + '\'' +
+                ", data=" + this.data + ", retry=" + this.retry + ", comment='" + this.comment + '\'' + ']');
     }
 
+
+	/**
+	 * Return a builder for a {@code SseEvent}.
+	 * @param <T> the type of data that this event contains
+	 * @return the builder
+	 */
+	public static <T> Builder<T> builder() {
+		return new BuilderImpl<>();
+	}
+
+	/**
+	 * Return a builder for a {@code SseEvent}, populated with the give {@linkplain #data() data}.
+	 * @param <T> the type of data that this event contains
+	 * @return the builder
+	 */
+	public static <T> Builder<T> builder(T data) {
+		return new BuilderImpl<>(data);
+	}
+
+
     /**
      * A mutable builder for a {@code SseEvent}.
      *

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -62,16 +62,17 @@ public ServerSentEventHttpMessageWriter() {
 	}
 
 	/**
-	 * Constructor with JSON {@code Encoder} for encoding objects. Support for
-	 * {@code String} event data is built-in.
+	 * Constructor with JSON {@code Encoder} for encoding objects.
+	 * Support for {@code String} event data is built-in.
+	 * @param encoder the Encoder to use (may be {@code null})
 	 */
 	public ServerSentEventHttpMessageWriter(Encoder<?> encoder) {
 		this.encoder = encoder;
 	}
 
 
 	/**
-	 * Return the configured {@code Encoder}, possibly {@code null}.
+	 * Return the configured {@code Encoder}, if any.
 	 */
 	public Encoder<?> getEncoder() {
 		return this.encoder;
@@ -85,8 +86,8 @@ public List<MediaType> getWritableMediaTypes() {
 
 	@Override
 	public boolean canWrite(ResolvableType elementType, MediaType mediaType) {
-		return mediaType == null || MediaType.TEXT_EVENT_STREAM.includes(mediaType) ||
-				ServerSentEvent.class.isAssignableFrom(elementType.resolve(Object.class));
+		return (mediaType == null || MediaType.TEXT_EVENT_STREAM.includes(mediaType) ||
+				ServerSentEvent.class.isAssignableFrom(elementType.resolve(Object.class)));
 	}
 
 	@Override
@@ -100,23 +101,33 @@ public Mono<Void> write(Publisher<?> input, ResolvableType elementType, MediaTyp
 	private Flux<Publisher<DataBuffer>> encode(Publisher<?> input, DataBufferFactory factory,
 			ResolvableType elementType, Map<String, Object> hints) {
 
-		ResolvableType valueType = ServerSentEvent.class.isAssignableFrom(elementType.getRawClass()) ?
-				elementType.getGeneric(0) : elementType;
+		ResolvableType valueType = (ServerSentEvent.class.isAssignableFrom(elementType.getRawClass()) ?
+				elementType.getGeneric() : elementType);
 
 		return Flux.from(input).map(element -> {
 
-			ServerSentEvent<?> sse = element instanceof ServerSentEvent ?
-					(ServerSentEvent<?>) element : ServerSentEvent.builder().data(element).build();
+			ServerSentEvent<?> sse = (element instanceof ServerSentEvent ?
+					(ServerSentEvent<?>) element : ServerSentEvent.builder().data(element).build());
 
 			StringBuilder sb = new StringBuilder();
-			sse.id().ifPresent(v -> writeField("id", v, sb));
-			sse.event().ifPresent(v -> writeField("event", v, sb));
-			sse.retry().ifPresent(v -> writeField("retry", v.toMillis(), sb));
-			sse.comment().ifPresent(v -> sb.append(':').append(v.replaceAll("\\n", "\n:")).append("\n"));
-			sse.data().ifPresent(v -> sb.append("data:"));
+			if (sse.id() != null) {
+				writeField("id", sse.id(), sb);
+			}
+			if (sse.event() != null) {
+				writeField("event", sse.event(), sb);
+			}
+			if (sse.retry() != null) {
+				writeField("retry", sse.retry().toMillis(), sb);
+			}
+			if (sse.comment() != null) {
+				sb.append(':').append(sse.comment().replaceAll("\\n", "\n:")).append("\n");
+			}
+			if (sse.data() != null) {
+				sb.append("data:");
+			}
 
 			return Flux.concat(encodeText(sb, factory),
-					encodeData(sse, valueType, factory, hints),
+					encodeData(sse.data(), valueType, factory, hints),
 					encodeText("\n", factory));
 		});
 	}
@@ -129,10 +140,9 @@ private void writeField(String fieldName, Object fieldValue, StringBuilder strin
 	}
 
 	@SuppressWarnings("unchecked")
-	private <T> Flux<DataBuffer> encodeData(ServerSentEvent<?> event, ResolvableType valueType,
+	private <T> Flux<DataBuffer> encodeData(T data, ResolvableType valueType,
 			DataBufferFactory factory, Map<String, Object> hints) {
 
-		Object data = event.data().orElse(null);
 		if (data == null) {
 			return Flux.empty();
 		}
@@ -147,7 +157,7 @@ private <T> Flux<DataBuffer> encodeData(ServerSentEvent<?> event, ResolvableType
 		}
 
 		return ((Encoder<T>) this.encoder)
-				.encode(Mono.just((T) data), factory, valueType, MediaType.TEXT_EVENT_STREAM, hints)
+				.encode(Mono.just(data), factory, valueType, MediaType.TEXT_EVENT_STREAM, hints)
 				.concatWith(encodeText("\n", factory));
 	}
 

spring-web/src/main/java/org/springframework/http/server/reactive/ReactorServerHttpRequest.java

@@ -19,7 +19,6 @@
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.util.Optional;
 
 import io.netty.handler.codec.http.cookie.Cookie;
 import reactor.core.publisher.Flux;
@@ -100,8 +99,8 @@ protected MultiValueMap<String, HttpCookie> initCookies() {
 	}
 
 	@Override
-	public Optional<InetSocketAddress> getRemoteAddress() {
-		return Optional.ofNullable(this.request.remoteAddress());
+	public InetSocketAddress getRemoteAddress() {
+		return this.request.remoteAddress();
 	}
 
 	@Override