Create DynamicRegistrationBean

Extract functionality from the `RegistrationBean` into a new class
designed to work with dynamic registration. Servet and Filter
registration beans now extend from `DynaimcRegistrationBean`, where as
`ServletListenerRegistrationBean` extends directly from
`RegistrationBean`.

This refactor allows the removal of `ServletListenerRegistrationBean`
deprecated methods.

Fixes gh-11344

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jersey/JerseyAutoConfiguration.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -56,8 +56,8 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplicat
 import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.boot.web.servlet.DynaimcRegistrationBean;
 import org.springframework.boot.web.servlet.FilterRegistrationBean;
-import org.springframework.boot.web.servlet.RegistrationBean;
 import org.springframework.boot.web.servlet.ServletRegistrationBean;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -181,7 +181,7 @@ public class JerseyAutoConfiguration implements ServletContextAware {
 		return ClassUtils.getUserClass(this.config.getClass()).getName();
 	}
 
-	private void addInitParameters(RegistrationBean registration) {
+	private void addInitParameters(DynaimcRegistrationBean<?> registration) {
 		for (Entry<String, String> entry : this.jersey.getInit().entrySet()) {
 			registration.addInitParameter(entry.getKey(), entry.getValue());
 		}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/AbstractFilterRegistrationBean.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -26,8 +26,8 @@ import java.util.Set;
 import javax.servlet.DispatcherType;
 import javax.servlet.Filter;
 import javax.servlet.FilterRegistration;
+import javax.servlet.FilterRegistration.Dynamic;
 import javax.servlet.ServletContext;
-import javax.servlet.ServletException;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -41,7 +41,8 @@ import org.springframework.util.Assert;
  * @param <T> the type of {@link Filter} to register
  * @author Phillip Webb
  */
-abstract class AbstractFilterRegistrationBean<T extends Filter> extends RegistrationBean {
+abstract class AbstractFilterRegistrationBean<T extends Filter>
+		extends DynaimcRegistrationBean<FilterRegistration.Dynamic> {
 
 	/**
 	 * Filters that wrap the servlet request should be ordered less than or equal to this.
@@ -208,34 +209,24 @@ abstract class AbstractFilterRegistrationBean<T extends Filter> extends Registra
 	}
 
 	@Override
-	public void onStartup(ServletContext servletContext) throws ServletException {
+	protected String getDescription() {
 		Filter filter = getFilter();
 		Assert.notNull(filter, "Filter must not be null");
-		String name = getOrDeduceName(filter);
-		if (!isEnabled()) {
-			this.logger.info("Filter " + name + " was not registered (disabled)");
-			return;
-		}
-		FilterRegistration.Dynamic added = servletContext.addFilter(name, filter);
-		if (added == null) {
-			this.logger.info("Filter " + name + " was not registered "
-					+ "(possibly already registered?)");
-			return;
-		}
-		configure(added);
+		return "filter " + getOrDeduceName(filter);
 	}
 
-	/**
-	 * Return the {@link Filter} to be registered.
-	 * @return the filter
-	 */
-	public abstract T getFilter();
+	@Override
+	protected Dynamic addRegistration(String description, ServletContext servletContext) {
+		Filter filter = getFilter();
+		return servletContext.addFilter(getOrDeduceName(filter), filter);
+	}
 
 	/**
 	 * Configure registration settings. Subclasses can override this method to perform
 	 * additional configuration if required.
 	 * @param registration the registration
 	 */
+	@Override
 	protected void configure(FilterRegistration.Dynamic registration) {
 		super.configure(registration);
 		EnumSet<DispatcherType> dispatcherTypes = this.dispatcherTypes;
@@ -269,4 +260,10 @@ abstract class AbstractFilterRegistrationBean<T extends Filter> extends Registra
 		}
 	}
 
+	/**
+	 * Return the {@link Filter} to be registered.
+	 * @return the filter
+	 */
+	public abstract T getFilter();
+
 }

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/DynaimcRegistrationBean.java

+/*
+ * Copyright 2012-2018 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.web.servlet;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+import javax.servlet.Registration;
+import javax.servlet.ServletContext;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.core.Conventions;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Base class for Servlet 3.0+ {@link javax.servlet.Registration.Dynamic dynamic} based
+ * registration beans.
+ *
+ * @param <D> The dynamic registration result
+ * @author Phillip Webb
+ * @since 2.0.0
+ */
+public abstract class DynaimcRegistrationBean<D extends Registration.Dynamic>
+		extends RegistrationBean {
+
+	private static final Log logger = LogFactory.getLog(RegistrationBean.class);
+
+	private String name;
+
+	private boolean asyncSupported = true;
+
+	private Map<String, String> initParameters = new LinkedHashMap<>();
+
+	/**
+	 * Set the name of this registration. If not specified the bean name will be used.
+	 * @param name the name of the registration
+	 */
+	public void setName(String name) {
+		Assert.hasLength(name, "Name must not be empty");
+		this.name = name;
+	}
+
+	/**
+	 * Sets if asynchronous operations are support for this registration. If not specified
+	 * defaults to {@code true}.
+	 * @param asyncSupported if async is supported
+	 */
+	public void setAsyncSupported(boolean asyncSupported) {
+		this.asyncSupported = asyncSupported;
+	}
+
+	/**
+	 * Returns if asynchronous operations are support for this registration.
+	 * @return if async is supported
+	 */
+	public boolean isAsyncSupported() {
+		return this.asyncSupported;
+	}
+
+	/**
+	 * Set init-parameters for this registration. Calling this method will replace any
+	 * existing init-parameters.
+	 * @param initParameters the init parameters
+	 * @see #getInitParameters
+	 * @see #addInitParameter
+	 */
+	public void setInitParameters(Map<String, String> initParameters) {
+		Assert.notNull(initParameters, "InitParameters must not be null");
+		this.initParameters = new LinkedHashMap<>(initParameters);
+	}
+
+	/**
+	 * Returns a mutable Map of the registration init-parameters.
+	 * @return the init parameters
+	 */
+	public Map<String, String> getInitParameters() {
+		return this.initParameters;
+	}
+
+	/**
+	 * Add a single init-parameter, replacing any existing parameter with the same name.
+	 * @param name the init-parameter name
+	 * @param value the init-parameter value
+	 */
+	public void addInitParameter(String name, String value) {
+		Assert.notNull(name, "Name must not be null");
+		this.initParameters.put(name, value);
+	}
+
+	@Override
+	protected final void register(String description, ServletContext servletContext) {
+		D registration = addRegistration(description, servletContext);
+		if (registration == null) {
+			logger.info(StringUtils.capitalize(description) + " was not registered "
+					+ "(possibly already registered?)");
+			return;
+		}
+		Assert.state(registration != null,
+				() -> "Registration is null. Was something already registered for "
+						+ description + "?");
+		configure(registration);
+	}
+
+	protected abstract D addRegistration(String description,
+			ServletContext servletContext);
+
+	protected void configure(D registration) {
+		registration.setAsyncSupported(this.asyncSupported);
+		if (!this.initParameters.isEmpty()) {
+			registration.setInitParameters(this.initParameters);
+		}
+	}
+
+	/**
+	 * Deduces the name for this registration. Will return user specified name or fallback
+	 * to convention based naming.
+	 * @param value the object used for convention based names
+	 * @return the deduced name
+	 */
+	protected final String getOrDeduceName(Object value) {
+		return (this.name != null ? this.name : Conventions.getVariableName(value));
+	}
+
+}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/RegistrationBean.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -16,14 +16,14 @@
 
 package org.springframework.boot.web.servlet;
 
-import java.util.LinkedHashMap;
-import java.util.Map;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
 
-import javax.servlet.Registration;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 
-import org.springframework.core.Conventions;
 import org.springframework.core.Ordered;
-import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * Base class for Servlet 3.0+ based registration beans.
@@ -37,41 +37,35 @@ import org.springframework.util.Assert;
  */
 public abstract class RegistrationBean implements ServletContextInitializer, Ordered {
 
-	private String name;
+	private static final Log logger = LogFactory.getLog(RegistrationBean.class);
 
 	private int order = Ordered.LOWEST_PRECEDENCE;
 
-	private boolean asyncSupported = true;
-
 	private boolean enabled = true;
 
-	private Map<String, String> initParameters = new LinkedHashMap<>();
-
-	/**
-	 * Set the name of this registration. If not specified the bean name will be used.
-	 * @param name the name of the registration
-	 */
-	public void setName(String name) {
-		Assert.hasLength(name, "Name must not be empty");
-		this.name = name;
+	@Override
+	public final void onStartup(ServletContext servletContext) throws ServletException {
+		String description = getDescription();
+		if (!isEnabled()) {
+			logger.info(StringUtils.capitalize(description)
+					+ " was not registered (disabled)");
+			return;
+		}
+		register(description, servletContext);
 	}
 
 	/**
-	 * Sets if asynchronous operations are support for this registration. If not specified
-	 * defaults to {@code true}.
-	 * @param asyncSupported if async is supported
+	 * Return a description of the registration. For example "Servlet resourceServlet"
+	 * @return a description of the registration
 	 */
-	public void setAsyncSupported(boolean asyncSupported) {
-		this.asyncSupported = asyncSupported;
-	}
+	protected abstract String getDescription();
 
 	/**
-	 * Returns if asynchronous operations are support for this registration.
-	 * @return if async is supported
+	 * Register this bean with the servlet context.
+	 * @param description a description of the item being registered
+	 * @param servletContext the servlet context
 	 */
-	public boolean isAsyncSupported() {
-		return this.asyncSupported;
-	}
+	protected abstract void register(String description, ServletContext servletContext);
 
 	/**
 	 * Flag to indicate that the registration is enabled.
@@ -89,60 +83,6 @@ public abstract class RegistrationBean implements ServletContextInitializer, Ord
 		return this.enabled;
 	}
 
-	/**
-	 * Set init-parameters for this registration. Calling this method will replace any
-	 * existing init-parameters.
-	 * @param initParameters the init parameters
-	 * @see #getInitParameters
-	 * @see #addInitParameter
-	 */
-	public void setInitParameters(Map<String, String> initParameters) {
-		Assert.notNull(initParameters, "InitParameters must not be null");
-		this.initParameters = new LinkedHashMap<>(initParameters);
-	}
-
-	/**
-	 * Returns a mutable Map of the registration init-parameters.
-	 * @return the init parameters
-	 */
-	public Map<String, String> getInitParameters() {
-		return this.initParameters;
-	}
-
-	/**
-	 * Add a single init-parameter, replacing any existing parameter with the same name.
-	 * @param name the init-parameter name
-	 * @param value the init-parameter value
-	 */
-	public void addInitParameter(String name, String value) {
-		Assert.notNull(name, "Name must not be null");
-		this.initParameters.put(name, value);
-	}
-
-	/**
-	 * Deduces the name for this registration. Will return user specified name or fallback
-	 * to convention based naming.
-	 * @param value the object used for convention based names
-	 * @return the deduced name
-	 */
-	protected final String getOrDeduceName(Object value) {
-		return (this.name != null ? this.name : Conventions.getVariableName(value));
-	}
-
-	/**
-	 * Configure registration base settings.
-	 * @param registration the registration
-	 */
-	protected void configure(Registration.Dynamic registration) {
-		Assert.state(registration != null,
-				() -> "Registration is null. Was something already registered for name=["
-						+ this.name + "]?");
-		registration.setAsyncSupported(this.asyncSupported);
-		if (!this.initParameters.isEmpty()) {
-			registration.setInitParameters(this.initParameters);
-		}
-	}
-
 	/**
 	 * Set the order of the registration bean.
 	 * @param order the order

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/ServletContextInitializerBeans.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -188,7 +188,6 @@ public class ServletContextInitializerBeans
 				// One that we haven't already seen
 				RegistrationBean registration = adapter.createRegistrationBean(beanName,
 						bean.getValue(), beans.size());
-				registration.setName(beanName);
 				registration.setOrder(order);
 				this.initializers.add(type, registration);
 				if (ServletContextInitializerBeans.logger.isDebugEnabled()) {
@@ -247,8 +246,8 @@ public class ServletContextInitializerBeans
 	}
 
 	/**
-	 * Adapter to convert a given Bean type into a {@link RegistrationBean} (and hence a
-	 * {@link ServletContextInitializer}.
+	 * Adapter to convert a given Bean type into a {@link DynaimcRegistrationBean} (and
+	 * hence a {@link ServletContextInitializer}.
 	 */
 	private interface RegistrationBeanAdapter<T> {
 
@@ -278,6 +277,7 @@ public class ServletContextInitializerBeans
 			}
 			ServletRegistrationBean<Servlet> bean = new ServletRegistrationBean<>(source,
 					url);
+			bean.setName(name);
 			bean.setMultipartConfig(this.multipartConfig);
 			return bean;
 		}
@@ -293,7 +293,9 @@ public class ServletContextInitializerBeans
 		@Override
 		public RegistrationBean createRegistrationBean(String name, Filter source,
 				int totalNumberOfSourceBeans) {
-			return new FilterRegistrationBean<>(source);
+			FilterRegistrationBean<Filter> bean = new FilterRegistrationBean<>(source);
+			bean.setName(name);
+			return bean;
 		}
 
 	}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/ServletListenerRegistrationBean.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -19,21 +19,16 @@ package org.springframework.boot.web.servlet;
 import java.util.Collections;
 import java.util.EventListener;
 import java.util.HashSet;
-import java.util.Map;
 import java.util.Set;
 
 import javax.servlet.ServletContext;
 import javax.servlet.ServletContextAttributeListener;
 import javax.servlet.ServletContextListener;
-import javax.servlet.ServletException;
 import javax.servlet.ServletRequestAttributeListener;
 import javax.servlet.ServletRequestListener;
 import javax.servlet.http.HttpSessionAttributeListener;
 import javax.servlet.http.HttpSessionListener;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
@@ -61,9 +56,6 @@ import org.springframework.util.ClassUtils;
 public class ServletListenerRegistrationBean<T extends EventListener>
 		extends RegistrationBean {
 
-	private static final Log logger = LogFactory
-			.getLog(ServletListenerRegistrationBean.class);
-
 	private static final Set<Class<?>> SUPPORTED_TYPES;
 
 	static {
@@ -106,80 +98,21 @@ public class ServletListenerRegistrationBean<T extends EventListener>
 	}
 
 	/**
-	 * Set the name of this registration. If not specified the bean name will be used.
-	 * @param name the name of the registration
-	 * @deprecated as of 1.5 since not applicable to listeners
-	 */
-	@Override
-	@Deprecated
-	public void setName(String name) {
-		super.setName(name);
-	}
-
-	/**
-	 * Sets if asynchronous operations are support for this registration. If not specified
-	 * defaults to {@code true}.
-	 * @param asyncSupported if async is supported
-	 * @deprecated as of 1.5 since not applicable to listeners
-	 */
-	@Override
-	@Deprecated
-	public void setAsyncSupported(boolean asyncSupported) {
-		super.setAsyncSupported(asyncSupported);
-	}
-
-	/**
-	 * Returns if asynchronous operations are support for this registration.
-	 * @return if async is supported
-	 * @deprecated as of 1.5 since not applicable to listeners
-	 */
-	@Override
-	@Deprecated
-	public boolean isAsyncSupported() {
-		return super.isAsyncSupported();
-	}
-
-	/**
-	 * Set init-parameters for this registration. Calling this method will replace any
-	 * existing init-parameters.
-	 * @param initParameters the init parameters
-	 * @deprecated as of 1.5 since not applicable to listeners
-	 */
-	@Override
-	@Deprecated
-	public void setInitParameters(Map<String, String> initParameters) {
-		super.setInitParameters(initParameters);
-	}
-
-	/**
-	 * Returns a mutable Map of the registration init-parameters.
-	 * @return the init parameters
-	 * @deprecated as of 1.5 since not applicable to listeners
+	 * Return the listener to be registered.
+	 * @return the listener to be registered
 	 */
-	@Override
-	@Deprecated
-	public Map<String, String> getInitParameters() {
-		return super.getInitParameters();
+	public T getListener() {
+		return this.listener;
 	}
 
-	/**
-	 * Add a single init-parameter, replacing any existing parameter with the same name.
-	 * @param name the init-parameter name
-	 * @param value the init-parameter value
-	 * @deprecated as of 1.5 since not applicable to listeners
-	 */
 	@Override
-	@Deprecated
-	public void addInitParameter(String name, String value) {
-		super.addInitParameter(name, value);
+	protected String getDescription() {
+		Assert.notNull(this.listener, "Listener must not be null");
+		return "listener " + this.listener;
 	}
 
 	@Override
-	public void onStartup(ServletContext servletContext) throws ServletException {
-		if (!isEnabled()) {
-			logger.info("Listener " + this.listener + " was not registered (disabled)");
-			return;
-		}
+	protected void register(String description, ServletContext servletContext) {
 		try {
 			servletContext.addListener(this.listener);
 		}
@@ -190,10 +123,6 @@ public class ServletListenerRegistrationBean<T extends EventListener>
 		}
 	}
 
-	public T getListener() {
-		return this.listener;
-	}
-
 	/**
 	 * Returns {@code true} if the specified listener is one of the supported types.
 	 * @param listener the listener to test

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/servlet/ServletRegistrationBean.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.
@@ -24,9 +24,7 @@ import java.util.Set;
 import javax.servlet.MultipartConfigElement;
 import javax.servlet.Servlet;
 import javax.servlet.ServletContext;
-import javax.servlet.ServletException;
 import javax.servlet.ServletRegistration;
-import javax.servlet.ServletRegistration.Dynamic;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -52,7 +50,8 @@ import org.springframework.util.ObjectUtils;
  * @see ServletContextInitializer
  * @see ServletContext#addServlet(String, Servlet)
  */
-public class ServletRegistrationBean<T extends Servlet> extends RegistrationBean {
+public class ServletRegistrationBean<T extends Servlet>
+		extends DynaimcRegistrationBean<ServletRegistration.Dynamic> {
 
 	private static final Log logger = LogFactory.getLog(ServletRegistrationBean.class);
 
@@ -172,30 +171,18 @@ public class ServletRegistrationBean<T extends Servlet> extends RegistrationBean
 		return this.multipartConfig;
 	}
 
-	/**
-	 * Returns the servlet name that will be registered.
-	 * @return the servlet name
-	 */
-	public String getServletName() {
-		return getOrDeduceName(this.servlet);
+	@Override
+	protected String getDescription() {
+		Assert.notNull(this.servlet, "Servlet must not be null");
+		return "servlet " + getServletName();
 	}
 
 	@Override
-	public void onStartup(ServletContext servletContext) throws ServletException {
-		Assert.notNull(this.servlet, "Servlet must not be null");
+	protected ServletRegistration.Dynamic addRegistration(String description,
+			ServletContext servletContext) {
 		String name = getServletName();
-		if (!isEnabled()) {
-			logger.info("Servlet " + name + " was not registered (disabled)");
-			return;
-		}
-		logger.info("Mapping servlet: '" + name + "' to " + this.urlMappings);
-		Dynamic added = servletContext.addServlet(name, this.servlet);
-		if (added == null) {
-			logger.info("Servlet " + name + " was not registered "
-					+ "(possibly already registered?)");
-			return;
-		}
-		configure(added);
+		logger.info("Servlet " + name + " mapped to " + this.urlMappings);
+		return servletContext.addServlet(name, this.servlet);
 	}
 
 	/**
@@ -203,6 +190,7 @@ public class ServletRegistrationBean<T extends Servlet> extends RegistrationBean
 	 * additional configuration if required.
 	 * @param registration the registration
 	 */
+	@Override
 	protected void configure(ServletRegistration.Dynamic registration) {
 		super.configure(registration);
 		String[] urlMapping = this.urlMappings
@@ -219,4 +207,11 @@ public class ServletRegistrationBean<T extends Servlet> extends RegistrationBean
 		}
 	}
 
+	/**
+	 * Returns the servlet name that will be registered.
+	 * @return the servlet name
+	 */
+	public String getServletName() {
+		return getOrDeduceName(this.servlet);
+	}
 }

spring-boot-samples/spring-boot-sample-actuator-ui/src/main/java/sample/actuator/ui/SampleActuatorUiApplication.java

 /*
- * Copyright 2012-2017 the original author or authors.
+ * Copyright 2012-2018 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.