Ordered WebMvcConfigurer interceptor registrations

Closes gh-22434

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/InterceptorRegistration.java

 /*
- * Copyright 2002-2018 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.
@@ -20,6 +20,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+import org.springframework.core.Ordered;
 import org.springframework.util.Assert;
 import org.springframework.util.PathMatcher;
 import org.springframework.util.StringUtils;
@@ -43,6 +44,8 @@ public class InterceptorRegistration {
 
 	private PathMatcher pathMatcher;
 
+	private int order = 0;
+
 
 	/**
 	 * Create an {@link InterceptorRegistration} instance.
@@ -80,6 +83,15 @@ public class InterceptorRegistration {
 		return this;
 	}
 
+	/**
+	 * Specify an order position to be used. Default is 0.
+	 * @since 4.23
+	 */
+	public InterceptorRegistration order(int order){
+		this.order = order;
+		return this;
+	}
+
 	/**
 	 * Build the underlying interceptor. If URL patterns are provided, the returned
 	 * type is {@link MappedInterceptor}; otherwise {@link HandlerInterceptor}.
@@ -98,4 +110,13 @@ public class InterceptorRegistration {
 		return mappedInterceptor;
 	}
 
+	Ordered toOrdered() {
+		return new Ordered() {
+			@Override
+			public int getOrder() {
+				return order;
+			}
+		};
+	}
+
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/InterceptorRegistry.java

 /*
- * Copyright 2002-2017 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.
@@ -17,8 +17,11 @@
 package org.springframework.web.servlet.config.annotation;
 
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 
+import org.springframework.core.OrderComparator;
 import org.springframework.web.context.request.WebRequestInterceptor;
 import org.springframework.web.servlet.HandlerInterceptor;
 import org.springframework.web.servlet.handler.WebRequestHandlerInterceptorAdapter;
@@ -64,11 +67,25 @@ public class InterceptorRegistry {
 	 * Return all registered interceptors.
 	 */
 	protected List<Object> getInterceptors() {
-		List<Object> interceptors = new ArrayList<Object>(this.registrations.size());
+		Collections.sort(this.registrations, INTERCEPTOR_ORDER_COMPARATOR);
+		List<Object> result = new ArrayList<Object>(this.registrations.size());
 		for (InterceptorRegistration registration : this.registrations) {
-			interceptors.add(registration.getInterceptor());
+			result.add(registration.getInterceptor());
 		}
-		return interceptors ;
+		return result;
 	}
 
+
+	private static final Comparator<Object> INTERCEPTOR_ORDER_COMPARATOR =
+			OrderComparator.INSTANCE.withSourceProvider(new OrderComparator.OrderSourceProvider() {
+				@Override
+				public Object getOrderSource(final Object object) {
+					if (object instanceof InterceptorRegistration) {
+						return ((InterceptorRegistration) object).toOrdered();
+					}
+					return null;
+				}
+			});
+
+
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/InterceptorRegistryTests.java

 /*
- * Copyright 2002-2014 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.
@@ -25,6 +25,7 @@ import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mockito;
 
+import org.springframework.core.Ordered;
 import org.springframework.mock.web.test.MockHttpServletRequest;
 import org.springframework.mock.web.test.MockHttpServletResponse;
 import org.springframework.ui.ModelMap;
@@ -150,6 +151,30 @@ public class InterceptorRegistryTests {
 		assertEquals(Collections.emptyList(), getInterceptorsForPath("/path1/secret"));
 	}
 
+	@Test
+	public void orderedInterceptors() {
+		this.registry.addInterceptor(this.interceptor1).order(Ordered.LOWEST_PRECEDENCE);
+		this.registry.addInterceptor(this.interceptor2).order(Ordered.HIGHEST_PRECEDENCE);
+
+		List<Object> interceptors = this.registry.getInterceptors();
+		assertEquals(2, interceptors.size());
+
+		assertSame(this.interceptor2, interceptors.get(0));
+		assertSame(this.interceptor1, interceptors.get(1));
+	}
+
+	@Test
+	public void nonOrderedInterceptors() {
+		this.registry.addInterceptor(this.interceptor1).order(0);
+		this.registry.addInterceptor(this.interceptor2).order(0);
+
+		List<Object> interceptors = this.registry.getInterceptors();
+		assertEquals(2, interceptors.size());
+
+		assertSame(this.interceptor1, interceptors.get(0));
+		assertSame(this.interceptor2, interceptors.get(1));
+	}
+
 
 	private List<HandlerInterceptor> getInterceptorsForPath(String lookupPath) {
 		PathMatcher pathMatcher = new AntPathMatcher();
@@ -177,6 +202,7 @@ public class InterceptorRegistryTests {
 		assertTrue(webInterceptor.preHandleInvoked);
 	}
 
+
 	private static class TestWebRequestInterceptor implements WebRequestInterceptor {
 
 		private boolean preHandleInvoked = false;