Merge branch '2.2.x'

spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/AddRequestHeaderGatewayFilterFactory.java

@@ -37,7 +37,9 @@ public class AddRequestHeaderGatewayFilterFactory extends AbstractNameValueGatew
 			@Override
 			public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
 				String value = ServerWebExchangeUtils.expand(exchange, config.getValue());
-				ServerHttpRequest request = exchange.getRequest().mutate().header(config.getName(), value).build();
+				ServerHttpRequest request = exchange.getRequest().mutate()
+						.headers(httpHeaders -> httpHeaders.add(config.getName(), value))
+						.build();
 
 				return chain.filter(exchange.mutate().request(request).build());
 			}

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/factory/AddRequestHeaderGatewayFilterFactoryTests.java

@@ -16,6 +16,7 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import java.util.Arrays;
 import java.util.Map;
 
 import org.junit.Test;
@@ -59,6 +60,18 @@ public class AddRequestHeaderGatewayFilterFactoryTests extends BaseWebClientTest
 				});
 	}
 
+	@Test
+	public void addRequestHeaderFilterWorksMultipleValues() {
+		testClient.get().uri("/multivalueheaders")
+				.header("Host", "www.addrequestheader.org").exchange()
+				.expectBody(Map.class).consumeWith(result -> {
+					Map<String, Object> headers = getMap(result.getResponseBody(),
+							"headers");
+					assertThat(headers).containsEntry("X-Request-Example",
+							Arrays.asList("ValueA", "ValueB"));
+				});
+	}
+
 	@Test
 	public void addRequestHeaderFilterWorksJavaDsl() {
 		testClient.get().uri("/headers").header("Host", "www.addrequestheaderjava.org").exchange().expectBody(Map.class)
@@ -68,6 +81,18 @@ public class AddRequestHeaderGatewayFilterFactoryTests extends BaseWebClientTest
 				});
 	}
 
+	@Test
+	public void addRequestHeaderFilterMultipleValuesWorksJavaDsl() {
+		testClient.get().uri("/multivalueheaders")
+				.header("Host", "www.addrequestheaderjava.org").exchange()
+				.expectBody(Map.class).consumeWith(result -> {
+					Map<String, Object> headers = getMap(result.getResponseBody(),
+							"headers");
+					assertThat(headers).containsEntry("X-Request-Acme",
+							Arrays.asList("ValueB-www", "ValueC-www"));
+				});
+	}
+
 	@Test
 	public void toStringFormat() {
 		NameValueConfig config = new NameValueConfig().setName("myname").setValue("myvalue");
@@ -89,6 +114,13 @@ public class AddRequestHeaderGatewayFilterFactoryTests extends BaseWebClientTest
 					r -> r.path("/headers").and().host("{sub}.addrequestheaderjava.org")
 							.filters(f -> f.prefixPath("/httpbin").addRequestHeader("X-Request-Acme", "ValueB-{sub}"))
 							.uri(uri))
+					.route("add_multiple_request_header_java_test", r -> r
+							.path("/multivalueheaders").and()
+							.host("{sub}.addrequestheaderjava.org")
+							.filters(f -> f.prefixPath("/httpbin")
+									.addRequestHeader("X-Request-Acme", "ValueB-{sub}")
+									.addRequestHeader("X-Request-Acme", "ValueC-{sub}"))
+							.uri(uri))
 					.build();
 		}
 

spring-cloud-gateway-server/src/test/resources/application-request-header-web-filter.yml

@@ -5,6 +5,13 @@ spring:
       - id: add_request_header_test
         uri: ${test.uri}
         predicates:
-        - Path=/headers
+          - Path=/headers
         filters:
-        - AddRequestHeader=X-Request-Example, ValueA
+          - AddRequestHeader=X-Request-Example, ValueA
+      - id: add_multiple_request_header_test
+        uri: ${test.uri}
+        predicates:
+          - Path=/multivalueheaders
+        filters:
+          - AddRequestHeader=X-Request-Example, ValueA
+          - AddRequestHeader=X-Request-Example, ValueB