Add enabled flag to RegistrationBean

Default to true but allow user to switch off a @Bean of type
Filter (for example) by wrapping it in a disabled registration.

Fixes gh-655

spring-boot/src/main/java/org/springframework/boot/context/embedded/FilterRegistrationBean.java

@@ -231,6 +231,10 @@ public class FilterRegistrationBean extends RegistrationBean {
 	public void onStartup(ServletContext servletContext) throws ServletException {
 		Assert.notNull(this.filter, "Filter must not be null");
 		String name = getOrDeduceName(this.filter);
+		if (!isEnabled()) {
+			logger.info("Filter " + name + " was not registered (disabled)");
+			return;
+		}
 		FilterRegistration.Dynamic added = servletContext.addFilter(name, this.filter);
 		if (added == null) {
 			logger.info("Filter " + name + " was not registered "

spring-boot/src/main/java/org/springframework/boot/context/embedded/RegistrationBean.java

@@ -41,6 +41,8 @@ public abstract class RegistrationBean implements ServletContextInitializer, Ord
 
 	private boolean asyncSupported = true;
 
+	private boolean enabled = true;
+
 	private Map<String, String> initParameters = new LinkedHashMap<String, String>();
 
 	/**
@@ -66,6 +68,22 @@ public abstract class RegistrationBean implements ServletContextInitializer, Ord
 		return this.asyncSupported;
 	}
 
+	/**
+	 * Flag to indicate that the registration is enabled.
+	 * 
+	 * @param enabled the enabled to set
+	 */
+	public void setEnabled(boolean enabled) {
+		this.enabled = enabled;
+	}
+
+	/**
+	 * @return the enabled flag (default true)
+	 */
+	public boolean isEnabled() {
+		return this.enabled;
+	}
+
 	/**
 	 * Set init-parameters for this registration. Calling this method will replace any
 	 * existing init-parameters.

spring-boot/src/main/java/org/springframework/boot/context/embedded/ServletListenerRegistrationBean.java

@@ -30,6 +30,8 @@ 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;
 
@@ -55,6 +57,8 @@ import org.springframework.util.ClassUtils;
 public class ServletListenerRegistrationBean<T extends EventListener> extends
 		RegistrationBean {
 
+	private static Log logger = LogFactory.getLog(ServletListenerRegistrationBean.class);
+
 	private static final Set<Class<?>> SUPPORTED_TYPES;
 	static {
 		Set<Class<?>> types = new HashSet<Class<?>>();
@@ -97,6 +101,10 @@ public class ServletListenerRegistrationBean<T extends EventListener> extends
 
 	@Override
 	public void onStartup(ServletContext servletContext) throws ServletException {
+		if (!isEnabled()) {
+			logger.info("Listener " + this.listener + " was not registered (disabled)");
+			return;
+		}
 		servletContext.addListener(this.listener);
 	}
 

spring-boot/src/main/java/org/springframework/boot/context/embedded/ServletRegistrationBean.java

@@ -158,6 +158,10 @@ public class ServletRegistrationBean extends RegistrationBean {
 	public void onStartup(ServletContext servletContext) throws ServletException {
 		Assert.notNull(this.servlet, "Servlet must not be null");
 		String name = getServletName();
+		if (!isEnabled()) {
+			logger.info("Filter " + name + " was not registered (disabled)");
+			return;
+		}
 		logger.info("Mapping servlet: '" + name + "' to " + this.urlMappings);
 		Dynamic added = servletContext.addServlet(name, this.servlet);
 		if (added == null) {

spring-boot/src/test/java/org/springframework/boot/context/embedded/FilterRegistrationBeanTests.java

@@ -36,6 +36,7 @@ import org.mockito.MockitoAnnotations;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Matchers.anyObject;
 import static org.mockito.Matchers.anyString;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
 /**
@@ -122,6 +123,15 @@ public class FilterRegistrationBeanTests {
 		verify(this.servletContext).addFilter("mockFilter", this.filter);
 	}
 
+	@Test
+	public void disable() throws Exception {
+		FilterRegistrationBean bean = new FilterRegistrationBean();
+		bean.setFilter(this.filter);
+		bean.setEnabled(false);
+		bean.onStartup(this.servletContext);
+		verify(this.servletContext, times(0)).addFilter("mockFilter", this.filter);
+	}
+
 	@Test
 	public void setFilterMustNotBeNull() throws Exception {
 		FilterRegistrationBean bean = new FilterRegistrationBean();

spring-boot/src/test/java/org/springframework/boot/context/embedded/ServletListenerRegistrationBeanTests.java

@@ -29,6 +29,8 @@ import org.mockito.Mock;
 import org.mockito.Mockito;
 import org.mockito.MockitoAnnotations;
 
+import static org.mockito.Matchers.any;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
 /**
@@ -60,6 +62,16 @@ public class ServletListenerRegistrationBeanTests {
 		verify(this.servletContext).addListener(this.listener);
 	}
 
+	@Test
+	public void disable() throws Exception {
+		ServletListenerRegistrationBean<ServletContextListener> bean = new ServletListenerRegistrationBean<ServletContextListener>(
+				this.listener);
+		bean.setEnabled(false);
+		bean.onStartup(this.servletContext);
+		verify(this.servletContext, times(0)).addListener(
+				any(ServletContextListener.class));
+	}
+
 	@Test
 	public void cannotRegisterUnsupportedType() throws Exception {
 		this.thrown.expect(IllegalArgumentException.class);

spring-boot/src/test/java/org/springframework/boot/context/embedded/ServletRegistrationBeanTests.java

@@ -39,6 +39,7 @@ import static org.mockito.BDDMockito.given;
 import static org.mockito.Matchers.anyObject;
 import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 
 /**
@@ -129,6 +130,15 @@ public class ServletRegistrationBeanTests {
 		verify(this.servletContext).addServlet("mockServlet", this.servlet);
 	}
 
+	@Test
+	public void disable() throws Exception {
+		ServletRegistrationBean bean = new ServletRegistrationBean();
+		bean.setServlet(this.servlet);
+		bean.setEnabled(false);
+		bean.onStartup(this.servletContext);
+		verify(this.servletContext, times(0)).addServlet("mockServlet", this.servlet);
+	}
+
 	@Test
 	public void setServletMustNotBeNull() throws Exception {
 		ServletRegistrationBean bean = new ServletRegistrationBean();