Fix LegacyCookieProcessor configuration example and test it

Closes gh-6827

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

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2012-2016 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.context.embedded;
+
+import org.apache.catalina.Context;
+import org.apache.tomcat.util.http.LegacyCookieProcessor;
+
+import org.springframework.boot.context.embedded.tomcat.TomcatContextCustomizer;
+import org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Example configuration for configuring Tomcat with to use {@link LegacyCookieProcessor}.
+ *
+ * @author Andy Wilkinson
+ */
+public class TomcatLegacyCookieProcessorExample {
+
+	/**
+	 * Configuration class that declares the required
+	 * {@link EmbeddedServletContainerCustomizer}.
+	 */
+	@Configuration
+	static class LegacyCookieProcessorConfiguration {
+
+		// tag::customizer[]
+		@Bean
+		public EmbeddedServletContainerCustomizer cookieProcessorCustomizer() {
+			return new EmbeddedServletContainerCustomizer() {
+
+				@Override
+				public void customize(ConfigurableEmbeddedServletContainer container) {
+					if (container instanceof TomcatEmbeddedServletContainerFactory) {
+						((TomcatEmbeddedServletContainerFactory) container)
+								.addContextCustomizers(new TomcatContextCustomizer() {
+
+							@Override
+							public void customize(Context context) {
+								context.setCookieProcessor(new LegacyCookieProcessor());
+							}
+
+						});
+					}
+				}
+
+			};
+		}
+		// end::customizer[]
+
+	}
+
+}