Fix nullability warnings and javadoc-triggered package cycles

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

@@ -168,7 +168,7 @@ public class AntPathMatcher implements PathMatcher {
 
 
 	@Override
-	public boolean isPattern(String path) {
+	public boolean isPattern(@Nullable String path) {
 		if (path == null) {
 			return false;
 		}
@@ -207,10 +207,10 @@ public class AntPathMatcher implements PathMatcher {
 	 * as far as the given base path goes is sufficient)
 	 * @return {@code true} if the supplied {@code path} matched, {@code false} if it didn't
 	 */
-	protected boolean doMatch(String pattern, String path, boolean fullMatch,
+	protected boolean doMatch(String pattern, @Nullable String path, boolean fullMatch,
 			@Nullable Map<String, String> uriTemplateVariables) {
 
-		if ((path == null) || (path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator))) {
+		if (path == null || path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
 			return false;
 		}
 
@@ -220,7 +220,6 @@ public class AntPathMatcher implements PathMatcher {
 		}
 
 		String[] pathDirs = tokenizePath(path);
-
 		int pattIdxStart = 0;
 		int pattIdxEnd = pattDirs.length - 1;
 		int pathIdxStart = 0;

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/DestinationVariable.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 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.
@@ -26,13 +26,12 @@ import java.lang.annotation.Target;
  * Annotation that indicates a method parameter should be bound to a template variable
  * in a destination template string. Supported on message handling methods such as
  * {@link MessageMapping @MessageMapping}.
- * <p>
- * A {@code @DestinationVariable} template variable is always required.
+ *
+ * <p>A {@code @DestinationVariable} template variable is always required.
  *
  * @author Brian Clozel
  * @author Rossen Stoyanchev
  * @since 4.0
- *
  * @see org.springframework.messaging.handler.annotation.MessageMapping
  * @see org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler
  */

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/MessageMapping.java

@@ -23,7 +23,6 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 import org.springframework.messaging.Message;
-import org.springframework.messaging.simp.annotation.SendToUser;
 
 /**
  * Annotation for mapping a {@link Message} onto a message-handling method by
@@ -65,11 +64,11 @@ import org.springframework.messaging.simp.annotation.SendToUser;
  * authenticated user.</li>
  * </ul>
  *
- * <p>How the return value is handled depends on the processing scenario.
- * For STOMP over WebSocket, it is turned into a message and sent to a default
- * response destination or to a custom destination specified with an
- * {@link SendTo @SendTo} or {@link SendToUser @SendToUser} annotation.
- * For RSocket, the response is used to reply to the stream request.
+ * <p>How the return value is handled depends on the processing scenario. For
+ * STOMP over WebSocket, it is turned into a message and sent to a default response
+ * destination or to a custom destination specified with an {@link SendTo @SendTo}
+ * or {@link org.springframework.messaging.simp.annotation.SendToUser @SendToUser}
+ * annotation. For RSocket, the response is used to reply to the stream request.
  *
  * <p>Specializations of this annotation including
  * {@link org.springframework.messaging.simp.annotation.SubscribeMapping @SubscribeMapping} or

spring-messaging/src/main/java/org/springframework/messaging/rsocket/annotation/support/DefaultClientResponderFactory.java

@@ -35,6 +35,7 @@ import org.springframework.util.RouteMatcher;
  */
 class DefaultClientResponderFactory implements ClientResponderFactory, ClientResponderFactory.Config {
 
+	@Nullable
 	private List<Object> handlers;
 
 	@Nullable
@@ -52,9 +53,10 @@ class DefaultClientResponderFactory implements ClientResponderFactory, ClientRes
 	@Nullable
 	private ArgumentResolverConfigurer argumentResolverConfigurer;
 
+
 	@Override
 	public ClientResponderFactory handlers(Object... handlers) {
-		Assert.notEmpty(handlers, "handlers should not be empty");
+		Assert.notEmpty(handlers, "Handlers array must not be empty");
 		this.handlers = Arrays.asList(handlers);
 		return this;
 	}
@@ -89,9 +91,10 @@ class DefaultClientResponderFactory implements ClientResponderFactory, ClientRes
 		return this;
 	}
 
+
 	@Override
 	public void accept(RSocketFactory.ClientRSocketFactory clientRSocketFactory) {
-		Assert.notEmpty(this.handlers, "handlers should not be empty");
+		Assert.state(this.handlers != null, "No handlers set");
 		RSocketMessageHandler messageHandler = new RSocketMessageHandler();
 		messageHandler.setHandlers(this.handlers);
 		if (this.strategies != null) {

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletResponse.java

@@ -232,9 +232,9 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @see #getContentAsString()
 	 */
 	public String getContentAsString(Charset fallbackCharset) throws UnsupportedEncodingException {
-		return isCharset() ?
+		return (isCharset() && this.characterEncoding != null ?
 				this.content.toString(this.characterEncoding) :
-				this.content.toString(fallbackCharset.name());
+				this.content.toString(fallbackCharset.name()));
 	}
 
 	@Override

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

@@ -438,7 +438,8 @@ public class FormHttpMessageConverter implements HttpMessageConverter<MultiValue
 		return builder.toString();
 	}
 
-	private void writeMultipart(MultiValueMap<String, Object> parts, MediaType contentType, HttpOutputMessage outputMessage)
+	private void writeMultipart(
+			MultiValueMap<String, Object> parts, @Nullable MediaType contentType, HttpOutputMessage outputMessage)
 			throws IOException {
 
 		// If the supplied content type is null, fall back to multipart/form-data.

spring-web/src/main/java/org/springframework/web/method/ControllerAdviceBean.java

@@ -110,13 +110,13 @@ public class ControllerAdviceBean implements Ordered {
 	public ControllerAdviceBean(String beanName, BeanFactory beanFactory, @Nullable ControllerAdvice controllerAdvice) {
 		Assert.hasText(beanName, "Bean name must contain text");
 		Assert.notNull(beanFactory, "BeanFactory must not be null");
-		Assert.isTrue(beanFactory.containsBean(beanName), () -> "BeanFactory [" + beanFactory
-				+ "] does not contain specified controller advice bean '" + beanName + "'");
+		Assert.isTrue(beanFactory.containsBean(beanName), () -> "BeanFactory [" + beanFactory +
+				"] does not contain specified controller advice bean '" + beanName + "'");
 
 		this.beanOrName = beanName;
 		this.beanType = getBeanType(beanName, beanFactory);
-		this.beanTypePredicate = (controllerAdvice != null ? createBeanTypePredicate(controllerAdvice)
-				: createBeanTypePredicate(this.beanType));
+		this.beanTypePredicate = (controllerAdvice != null ? createBeanTypePredicate(controllerAdvice) :
+				createBeanTypePredicate(this.beanType));
 		this.beanFactory = beanFactory;
 	}
 
@@ -140,8 +140,11 @@ public class ControllerAdviceBean implements Ordered {
 			if (resolvedBean instanceof Ordered) {
 				this.order = ((Ordered) resolvedBean).getOrder();
 			}
+			else if (this.beanType != null) {
+				this.order = OrderUtils.getOrder(this.beanType, Ordered.LOWEST_PRECEDENCE);
+			}
 			else {
-				this.order = OrderUtils.getOrder(getBeanType(), Ordered.LOWEST_PRECEDENCE);
+				this.order = Ordered.LOWEST_PRECEDENCE;
 			}
 		}
 		return this.order;
@@ -236,18 +239,19 @@ public class ControllerAdviceBean implements Ordered {
 		return adviceBeans;
 	}
 
+	@Nullable
 	private static Class<?> getBeanType(String beanName, BeanFactory beanFactory) {
 		Class<?> beanType = beanFactory.getType(beanName);
 		return (beanType != null ? ClassUtils.getUserClass(beanType) : null);
 	}
 
-	private static HandlerTypePredicate createBeanTypePredicate(Class<?> beanType) {
+	private static HandlerTypePredicate createBeanTypePredicate(@Nullable Class<?> beanType) {
 		ControllerAdvice controllerAdvice = (beanType != null ?
 				AnnotatedElementUtils.findMergedAnnotation(beanType, ControllerAdvice.class) : null);
 		return createBeanTypePredicate(controllerAdvice);
 	}
 
-	private static HandlerTypePredicate createBeanTypePredicate(ControllerAdvice controllerAdvice) {
+	private static HandlerTypePredicate createBeanTypePredicate(@Nullable ControllerAdvice controllerAdvice) {
 		if (controllerAdvice != null) {
 			return HandlerTypePredicate.builder()
 					.basePackage(controllerAdvice.basePackages())

spring-web/src/test/java/org/springframework/mock/web/test/MockHttpServletResponse.java

@@ -231,11 +231,10 @@ public class MockHttpServletResponse implements HttpServletResponse {
 	 * @since 5.2
 	 * @see #getContentAsString()
 	 */
-
 	public String getContentAsString(Charset fallbackCharset) throws UnsupportedEncodingException {
-		return isCharset() ?
+		return (isCharset() && this.characterEncoding != null ?
 				this.content.toString(this.characterEncoding) :
-				this.content.toString(fallbackCharset.name());
+				this.content.toString(fallbackCharset.name()));
 	}
 
 	@Override

spring-webflux/src/main/java/org/springframework/web/reactive/result/view/script/ScriptTemplateView.java

@@ -124,6 +124,7 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 
 	/**
 	 * See {@link ScriptTemplateConfigurer#setEngineSupplier(Supplier)} documentation.
+	 * @since 5.2
 	 */
 	public void setEngineSupplier(Supplier<ScriptEngine> engineSupplier) {
 		this.engineSupplier = engineSupplier;
@@ -276,8 +277,9 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 	}
 
 	private ScriptEngine createEngineFromSupplier() {
+		Assert.state(this.engineSupplier != null, "No engine supplier available");
 		ScriptEngine engine = this.engineSupplier.get();
-		if (this.renderFunction != null && engine != null) {
+		if (this.renderFunction != null) {
 			Assert.isInstanceOf(Invocable.class, engine,
 					"ScriptEngine must implement Invocable when 'renderFunction' is specified");
 		}

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

@@ -144,6 +144,7 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 
 	/**
 	 * See {@link ScriptTemplateConfigurer#setEngineSupplier(Supplier)} documentation.
+	 * @since 5.2
 	 */
 	public void setEngineSupplier(Supplier<ScriptEngine> engineSupplier) {
 		this.engineSupplier = engineSupplier;
@@ -286,9 +287,8 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 				engines = new HashMap<>(4);
 				enginesHolder.set(engines);
 			}
-			String name = (this.engineName != null ? this.engineName : this.engineSupplier.getClass().getSimpleName());
-			Object engineKey = (!ObjectUtils.isEmpty(this.scripts) ?
-					new EngineKey(name, this.scripts) : name);
+			String name = (this.engineName != null ? this.engineName : "");
+			Object engineKey = (!ObjectUtils.isEmpty(this.scripts) ? new EngineKey(name, this.scripts) : name);
 			ScriptEngine engine = engines.get(engineKey);
 			if (engine == null) {
 				if (this.engineName != null) {
@@ -308,18 +308,22 @@ public class ScriptTemplateView extends AbstractUrlBasedView {
 		}
 	}
 
-	protected ScriptEngine createEngineFromName(@Nullable String engineName) {
-		if (this.scriptEngineManager == null) {
-			this.scriptEngineManager = new ScriptEngineManager(obtainApplicationContext().getClassLoader());
+	protected ScriptEngine createEngineFromName(String engineName) {
+		ScriptEngineManager scriptEngineManager = this.scriptEngineManager;
+		if (scriptEngineManager == null) {
+			scriptEngineManager = new ScriptEngineManager(obtainApplicationContext().getClassLoader());
+			this.scriptEngineManager = scriptEngineManager;
 		}
-		ScriptEngine engine = StandardScriptUtils.retrieveEngineByName(this.scriptEngineManager, engineName);
+
+		ScriptEngine engine = StandardScriptUtils.retrieveEngineByName(scriptEngineManager, engineName);
 		loadScripts(engine);
 		return engine;
 	}
 
 	private ScriptEngine createEngineFromSupplier() {
+		Assert.state(this.engineSupplier != null, "No engine supplier available");
 		ScriptEngine engine = this.engineSupplier.get();
-		if (this.renderFunction != null && engine != null) {
+		if (this.renderFunction != null) {
 			Assert.isInstanceOf(Invocable.class, engine,
 					"ScriptEngine must implement Invocable when 'renderFunction' is specified");
 		}