Moves to named Tuple args

Moves WebFilterFactory used to named Tuple arguments rather than a String array.

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteLocator.java

@@ -18,7 +18,6 @@
 package org.springframework.cloud.gateway.discovery;
 
 import java.net.URI;
-import java.util.Collections;
 
 import org.springframework.cloud.client.discovery.DiscoveryClient;
 import org.springframework.cloud.gateway.api.RouteLocator;
@@ -28,6 +27,8 @@ import org.springframework.cloud.gateway.model.FilterDefinition;
 import org.springframework.cloud.gateway.model.PredicateDefinition;
 import org.springframework.cloud.gateway.model.Route;
 
+import static org.springframework.cloud.gateway.filter.factory.RewritePathWebFilterFactory.REGEXP_KEY;
+import static org.springframework.cloud.gateway.filter.factory.RewritePathWebFilterFactory.REPLACEMENT_KEY;
 import static org.springframework.cloud.gateway.handler.predicate.PathRequestPredicateFactory.PATTERN_KEY;
 import static org.springframework.cloud.gateway.support.NameUtils.normalizeFilterName;
 import static org.springframework.cloud.gateway.support.NameUtils.normalizePredicateName;
@@ -59,7 +60,7 @@ public class DiscoveryClientRouteLocator implements RouteLocator {
 					// add a predicate that matches the url at /serviceId/**
 					PredicateDefinition predicate = new PredicateDefinition();
 					predicate.setName(normalizePredicateName(PathRequestPredicateFactory.class));
-					predicate.setArgs(Collections.singletonMap(PATTERN_KEY, "/" + serviceId + "/**"));
+					predicate.addArg(PATTERN_KEY, "/" + serviceId + "/**");
 					route.getPredicates().add(predicate);
 
 					//TODO: support for other default predicates
@@ -69,7 +70,8 @@ public class DiscoveryClientRouteLocator implements RouteLocator {
 					filter.setName(normalizeFilterName(RewritePathWebFilterFactory.class));
 					String regex = "/" + serviceId + "/(?<remaining>.*)";
 					String replacement = "/${remaining}";
-					filter.setArgs(regex, replacement);
+					filter.addArg(REGEXP_KEY, regex);
+					filter.addArg(REPLACEMENT_KEY, replacement);
 					route.getFilters().add(filter);
 
 					//TODO: support for default filters

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/AddRequestHeaderWebFilterFactory.java

@@ -17,21 +17,31 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class AddRequestHeaderWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY, VALUE_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		String name = args.getString(NAME_KEY);
+		String value = args.getString(VALUE_KEY);
 
 		return (exchange, chain) -> {
 			ServerHttpRequest request = exchange.getRequest().mutate()
-					.header(args[0], args[1])
+					.header(name, value)
 					.build();
 
 			return chain.filter(exchange.mutate().request(request).build());

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/AddRequestParameterWebFilterFactory.java

@@ -19,11 +19,14 @@ package org.springframework.cloud.gateway.filter.factory;
 
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.Arrays;
+import java.util.List;
 
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
+import org.springframework.tuple.Tuple;
 import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 import org.springframework.web.server.WebFilter;
@@ -34,10 +37,14 @@ import org.springframework.web.server.WebFilter;
 public class AddRequestParameterWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
-		String parameter = args[0];
-		String value = args[1];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY, VALUE_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		String parameter = args.getString(NAME_KEY);
+		String value = args.getString(VALUE_KEY);
 
 		return (exchange, chain) -> {
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/AddResponseHeaderWebFilterFactory.java

@@ -17,18 +17,26 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class AddResponseHeaderWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
-		final String header = args[0];
-		final String value = args[1];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY, VALUE_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String header = args.getString(NAME_KEY);
+		final String value = args.getString(VALUE_KEY);
 
 		return (exchange, chain) -> {
 			exchange.getResponse().getHeaders().add(header, value);

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixWebFilterFactory.java

@@ -17,6 +17,7 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;
@@ -30,15 +31,22 @@ import rx.Observable;
 import rx.RxReactiveStreams;
 import rx.Subscription;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class HystrixWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		final String commandName = args[0];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String commandName = args.getString(NAME_KEY);
 		final HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey(getClass().getSimpleName());
 		final HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey(commandName);
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/PrefixPathWebFilterFactory.java

@@ -18,18 +18,28 @@
 package org.springframework.cloud.gateway.filter.factory;
 
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class PrefixPathWebFilterFactory implements WebFilterFactory {
 
+	public static final String PREFIX_KEY = "prefix";
+
+	@Override
+	public List<String> argNames() {
+		return Arrays.asList(PREFIX_KEY);
+	}
+
 	@Override
 	@SuppressWarnings("unchecked")
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		final String prefix = args[0];
+	public WebFilter apply(Tuple args) {
+		final String prefix = args.getString(PREFIX_KEY);
 
 		return (exchange, chain) -> {
 			ServerHttpRequest req = exchange.getRequest();

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/RedirectToWebFilterFactory.java

@@ -20,10 +20,13 @@ package org.springframework.cloud.gateway.filter.factory;
 import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URL;
+import java.util.Arrays;
+import java.util.List;
 
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.parse;
@@ -35,18 +38,26 @@ import reactor.core.publisher.Mono;
  * @author Spencer Gibb
  */
 public class RedirectToWebFilterFactory implements WebFilterFactory {
+
+	public static final String STATUS_KEY = "status";
+	public static final String URL_KEY = "url";
+
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
-		final String statusString = args[0];
-		final String uri = args[1];
+	public List<String> argNames() {
+		return Arrays.asList(STATUS_KEY, URL_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		String statusString = args.getRawString(STATUS_KEY);
+		String urlString = args.getString(URL_KEY);
 
 		final HttpStatus httpStatus = parse(statusString);
 		final URL url;
 		try {
-			url = URI.create(uri).toURL();
+			url = URI.create(urlString).toURL();
 		} catch (MalformedURLException e) {
-			throw new IllegalArgumentException("Invalid url " + uri, e);
+			throw new IllegalArgumentException("Invalid url " + urlString, e);
 		}
 
 		return (exchange, chain) ->

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/RemoveNonProxyHeadersWebFilterFactory.java

@@ -19,6 +19,7 @@ package org.springframework.cloud.gateway.filter.factory;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
 import java.util.Arrays;
@@ -61,7 +62,7 @@ public class RemoveNonProxyHeadersWebFilterFactory implements WebFilterFactory {
 	}
 
 	@Override
-	public WebFilter apply(String... args) {
+	public WebFilter apply(Tuple args) {
 		//TODO: support filter args
 
 		return (exchange, chain) -> {

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/RemoveRequestHeaderWebFilterFactory.java

@@ -17,9 +17,13 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
@@ -28,9 +32,13 @@ public class RemoveRequestHeaderWebFilterFactory implements WebFilterFactory {
 	private static final String FAKE_HEADER = "_______force_______";
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		final String header = args[0];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String header = args.getString(NAME_KEY);
 
 		return (exchange, chain) -> {
 			ServerHttpRequest request = exchange.getRequest().mutate()

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/RemoveResponseHeaderWebFilterFactory.java

@@ -17,17 +17,25 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class RemoveResponseHeaderWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		final String header = args[0];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String header = args.getString(NAME_KEY);
 
 		return (exchange, chain) -> {
 			exchange.getResponse().getHeaders().remove(header);

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/RewritePathWebFilterFactory.java

@@ -17,19 +17,30 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class RewritePathWebFilterFactory implements WebFilterFactory {
 
+	public static final String REGEXP_KEY = "regexp";
+	public static final String REPLACEMENT_KEY = "replacement";
+
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
-		final String regex = args[0];
-		String replacement = args[1].replace("$\\", "$");
+	public List<String> argNames() {
+		return Arrays.asList(REGEXP_KEY, REPLACEMENT_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String regex = args.getString(REGEXP_KEY);
+		String replacement = args.getString(REPLACEMENT_KEY).replace("$\\", "$");
 
 		return (exchange, chain) -> {
 			ServerHttpRequest req = exchange.getRequest();

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SecureHeadersWebFilterFactory.java

@@ -18,6 +18,7 @@
 package org.springframework.cloud.gateway.filter.factory;
 
 import org.springframework.http.HttpHeaders;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
 /**
@@ -42,7 +43,7 @@ public class SecureHeadersWebFilterFactory implements WebFilterFactory {
 	}
 
 	@Override
-	public WebFilter apply(String... args) {
+	public WebFilter apply(Tuple args) {
 		//TODO: allow args to override properties
 
 		return (exchange, chain) -> {

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SetPathWebFilterFactory.java

@@ -18,9 +18,12 @@
 package org.springframework.cloud.gateway.filter.factory;
 
 import java.net.URI;
+import java.util.Arrays;
+import java.util.List;
 import java.util.Map;
 
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.util.UriTemplate;
 
@@ -32,11 +35,18 @@ import static org.springframework.web.reactive.function.server.RouterFunctions.U
  */
 public class SetPathWebFilterFactory implements WebFilterFactory {
 
+	public static final String TEMPLATE_KEY = "template";
+
+	@Override
+	public List<String> argNames() {
+		return Arrays.asList(TEMPLATE_KEY);
+	}
+
 	@Override
 	@SuppressWarnings("unchecked")
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		UriTemplate uriTemplate = new UriTemplate(args[0]);
+	public WebFilter apply(Tuple args) {
+		String template = args.getString(TEMPLATE_KEY);
+		UriTemplate uriTemplate = new UriTemplate(template);
 
 		return (exchange, chain) -> {
 			Map<String, String> variables = getAttribute(exchange, URI_TEMPLATE_VARIABLES_ATTRIBUTE, Map.class);

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SetResponseHeaderWebFilterFactory.java

@@ -17,18 +17,26 @@
 
 package org.springframework.cloud.gateway.filter.factory;
 
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class SetResponseHeaderWebFilterFactory implements WebFilterFactory {
 
 	@Override
-	public WebFilter apply(String... args) {
-		validate(2, args);
-		final String header = args[0];
-		final String value = args[1];
+	public List<String> argNames() {
+		return Arrays.asList(NAME_KEY, VALUE_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		final String header = args.getString(NAME_KEY);
+		final String value = args.getString(VALUE_KEY);
 
 		return (exchange, chain) -> {
 			exchange.getResponse().getHeaders().set(header, value);

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SetStatusWebFilterFactory.java

@@ -19,21 +19,32 @@ package org.springframework.cloud.gateway.filter.factory;
 
 import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
 import org.springframework.http.HttpStatus;
+import org.springframework.tuple.Tuple;
 import org.springframework.web.server.WebFilter;
 
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.setResponseStatus;
 
 import reactor.core.publisher.Mono;
 
+import java.util.Arrays;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 public class SetStatusWebFilterFactory implements WebFilterFactory {
 
+	public static final String STATUS_KEY = "status";
+
 	@Override
-	public WebFilter apply(String... args) {
-		validate(1, args);
-		final HttpStatus httpStatus = ServerWebExchangeUtils.parse(args[0]);
+	public List<String> argNames() {
+		return Arrays.asList(STATUS_KEY);
+	}
+
+	@Override
+	public WebFilter apply(Tuple args) {
+		String status = args.getRawString(STATUS_KEY);
+		final HttpStatus httpStatus = ServerWebExchangeUtils.parse(status);
 
 		return (exchange, chain) -> {
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/WebFilterFactory.java

@@ -18,24 +18,48 @@
 package org.springframework.cloud.gateway.filter.factory;
 
 import org.springframework.cloud.gateway.support.NameUtils;
+import org.springframework.tuple.Tuple;
 import org.springframework.util.Assert;
 import org.springframework.web.server.WebFilter;
 
+import java.util.Collections;
+import java.util.List;
+
 /**
  * @author Spencer Gibb
  */
 @FunctionalInterface
 public interface WebFilterFactory {
 
+	String NAME_KEY = "name";
+	String VALUE_KEY = "value";
+
 	//TODO: move from String... to Tuple
-	WebFilter apply(String... args);
+	WebFilter apply(Tuple args);
 
 	default String name() {
 		return NameUtils.normalizeFilterName(getClass());
 	}
 
-	default void validate(int requiredSize, String... args) {
-		Assert.isTrue(args != null && args.length == requiredSize,
+	/**
+	 * Returns hints about the number of args and the order for shortcut parsing.
+	 * @return
+	 */
+	default List<String> argNames() {
+		return Collections.emptyList();
+	}
+
+	/**
+	 * Validate supplied argument size against {@see #argNames} size.
+	 * Useful for variable arg predicates.
+	 * @return
+	 */
+	default boolean validateArgs() {
+		return true;
+	}
+
+	default void validate(int requiredSize, Tuple args) {
+		Assert.isTrue(args != null && args.size() == requiredSize,
 				"args must have "+ requiredSize +" entry(s)");
 	}
 }

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/handler/FilteringWebHandler.java

@@ -18,7 +18,6 @@
 package org.springframework.cloud.gateway.handler;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -36,10 +35,13 @@ import org.springframework.cloud.gateway.model.FilterDefinition;
 import org.springframework.cloud.gateway.model.Route;
 import org.springframework.cloud.gateway.config.GatewayProperties;
 import org.springframework.cloud.gateway.filter.GlobalFilter;
+import org.springframework.cloud.gateway.support.NameUtils;
 import org.springframework.cloud.gateway.support.RefreshRoutesEvent;
 import org.springframework.context.event.EventListener;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
+import org.springframework.tuple.Tuple;
+import org.springframework.tuple.TupleBuilder;
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;
@@ -153,16 +155,49 @@ public class FilteringWebHandler extends WebHandlerDecorator {
 					if (filter == null) {
 						throw new IllegalArgumentException("Unable to find WebFilterFactory with name " + definition.getName());
 					}
+					Map<String, String> args = definition.getArgs();
 					if (logger.isDebugEnabled()) {
-						List<String> args;
-						if (definition.getArgs() != null) {
-							args = Arrays.asList(definition.getArgs());
-						} else {
-							args = Collections.emptyList();
-						}
 						logger.debug("Route " + id + " applying filter " + args + " to " + definition.getName());
 					}
-					return filter.apply(definition.getArgs());
+
+					//TODO: move Tuple building to common class, see RequestPredicateFactory.lookup
+					TupleBuilder builder = TupleBuilder.tuple();
+
+					List<String> argNames = filter.argNames();
+					if (!argNames.isEmpty()) {
+						// ensure size is the same for key replacement later
+						if (filter.validateArgs() && args.size() != argNames.size()) {
+							throw new IllegalArgumentException("Wrong number of arguments. Expected " + argNames
+									+ " " + argNames + ". Found " + args.size() + " " + args + "'");
+						}
+					}
+
+					int entryIdx = 0;
+					for (Map.Entry<String, String> entry : args.entrySet()) {
+						String key = entry.getKey();
+
+						// RequestPredicateFactory has name hints and this has a fake key name
+						// replace with the matching key hint
+						if (key.startsWith(NameUtils.GENERATED_NAME_PREFIX) && !argNames.isEmpty()
+								&& entryIdx < args.size()) {
+							key = argNames.get(entryIdx);
+						}
+
+						builder.put(key, entry.getValue());
+						entryIdx++;
+					}
+
+					Tuple tuple = builder.build();
+
+					if (filter.validateArgs()) {
+						for (String name : argNames) {
+							if (!tuple.hasFieldName(name)) {
+								throw new IllegalArgumentException("Missing argument '" + name + "'. Given " + tuple);
+							}
+						}
+					}
+
+					return filter.apply(tuple);
 				})
 				.collect(Collectors.toList());
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/handler/RequestPredicateHandlerMapping.java

@@ -170,10 +170,12 @@ public class RequestPredicateHandlerMapping extends AbstractHandlerMapping {
 
 		List<String> argNames = found.argNames();
 		if (!argNames.isEmpty()) {
-			// ensure size is the same for key replacement later
-			if (found.validateArgSize() && args.size() != argNames.size()) {
-				throw new IllegalArgumentException("Wrong number of arguments. Expected " + argNames
-						+ " " + argNames + ". Found "+ args.size() +" " + args +"'");
+			if (!argNames.isEmpty()) {
+				// ensure size is the same for key replacement later
+				if (found.validateArgs() && args.size() != argNames.size()) {
+					throw new IllegalArgumentException("Wrong number of arguments. Expected " + argNames
+							+ " " + argNames + ". Found " + args.size() + " " + args + "'");
+				}
 			}
 		}
 
@@ -193,6 +195,15 @@ public class RequestPredicateHandlerMapping extends AbstractHandlerMapping {
 		}
 
 		Tuple tuple = builder.build();
+
+		if (found.validateArgs()) {
+			for (String name : argNames) {
+				if (!tuple.hasFieldName(name)) {
+					throw new IllegalArgumentException("Missing argument '" + name + "'. Given " + tuple);
+				}
+			}
+		}
+
 		return found.apply(tuple);
 	}
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/handler/predicate/QueryRequestPredicateFactory.java

@@ -39,7 +39,7 @@ public class QueryRequestPredicateFactory implements RequestPredicateFactory {
 	}
 
 	@Override
-	public boolean validateArgSize() {
+	public boolean validateArgs() {
 		return false;
 	}
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/handler/predicate/RequestPredicateFactory.java

@@ -46,11 +46,11 @@ public interface RequestPredicateFactory {
 	}
 
 	/**
-	 * Validate supplied argument size against {@see #argNames} size.
+	 * Auto validate supplied argument size against {@see #argNames} size and that an arg for each key exists.
 	 * Useful for variable arg predicates.
 	 * @return
 	 */
-	default boolean validateArgSize() {
+	default boolean validateArgs() {
 		return true;
 	}
 

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/model/FilterDefinition.java

@@ -17,11 +17,14 @@
 
 package org.springframework.cloud.gateway.model;
 
-import java.util.Arrays;
+import java.util.LinkedHashMap;
+import java.util.Map;
 import java.util.Objects;
 
 import javax.validation.constraints.NotNull;
 
+import org.springframework.cloud.gateway.support.NameUtils;
+
 import static org.springframework.util.StringUtils.tokenizeToStringArray;
 
 /**
@@ -30,7 +33,7 @@ import static org.springframework.util.StringUtils.tokenizeToStringArray;
 public class FilterDefinition {
 	@NotNull
 	private String name;
-	private String[] args;
+	private Map<String, String> args = new LinkedHashMap<>();
 
 	public FilterDefinition() {
 	}
@@ -45,7 +48,9 @@ public class FilterDefinition {
 
 		String[] args = tokenizeToStringArray(text.substring(eqIdx+1), ",");
 
-		setArgs(args);
+		for (int i=0; i < args.length; i++) {
+			this.args.put(NameUtils.generateName(i), args[i]);
+		}
 	}
 
 	public String getName() {
@@ -56,21 +61,25 @@ public class FilterDefinition {
 		this.name = name;
 	}
 
-	public String[] getArgs() {
+	public Map<String, String> getArgs() {
 		return args;
 	}
 
-	public void setArgs(String... args) {
+	public void setArgs(Map<String, String> args) {
 		this.args = args;
 	}
 
+	public void addArg(String key, String value) {
+		this.args.put(key, value);
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) return true;
 		if (o == null || getClass() != o.getClass()) return false;
 		FilterDefinition that = (FilterDefinition) o;
 		return Objects.equals(name, that.name) &&
-				Arrays.equals(args, that.args);
+				Objects.equals(args, that.args);
 	}
 
 	@Override
@@ -82,7 +91,7 @@ public class FilterDefinition {
 	public String toString() {
 		final StringBuilder sb = new StringBuilder("FilterDefinition{");
 		sb.append("name='").append(name).append('\'');
-		sb.append(", args=").append(Arrays.toString(args));
+		sb.append(", args=").append(args);
 		sb.append('}');
 		return sb.toString();
 	}

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/model/PredicateDefinition.java

@@ -70,6 +70,10 @@ public class PredicateDefinition {
 		this.args = args;
 	}
 
+	public void addArg(String key, String value) {
+		this.args.put(key, value);
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) return true;

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/RewritePathWebFilterFactoryTests.java

@@ -20,16 +20,20 @@ package org.springframework.cloud.gateway.filter.factory;
 import org.assertj.core.api.Assertions;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
-import org.springframework.web.server.WebFilter;
 import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
 import org.springframework.mock.http.server.reactive.MockServerHttpResponse;
 import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.server.WebFilter;
 import org.springframework.web.server.WebFilterChain;
 import org.springframework.web.server.adapter.DefaultServerWebExchange;
-import reactor.core.publisher.Mono;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
+import static org.springframework.cloud.gateway.filter.factory.RewritePathWebFilterFactory.REGEXP_KEY;
+import static org.springframework.cloud.gateway.filter.factory.RewritePathWebFilterFactory.REPLACEMENT_KEY;
+import static org.springframework.tuple.TupleBuilder.tuple;
+
+import reactor.core.publisher.Mono;
 
 /**
  * @author Spencer Gibb
@@ -47,7 +51,7 @@ public class RewritePathWebFilterFactoryTests {
 	}
 
 	private void testRewriteFilter(String regex, String replacement, String actualPath, String expectedPath) {
-		WebFilter filter = new RewritePathWebFilterFactory().apply(regex, replacement);
+		WebFilter filter = new RewritePathWebFilterFactory().apply(tuple().of(REGEXP_KEY, regex, REPLACEMENT_KEY, replacement));
 
 		MockServerHttpRequest request = MockServerHttpRequest
 				.get("http://localhost"+ actualPath)

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/SetPathWebFilterFactoryTests.java

@@ -32,6 +32,8 @@ import org.springframework.web.server.adapter.DefaultServerWebExchange;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
+import static org.springframework.cloud.gateway.filter.factory.SetPathWebFilterFactory.TEMPLATE_KEY;
+import static org.springframework.tuple.TupleBuilder.tuple;
 
 import reactor.core.publisher.Mono;
 
@@ -54,7 +56,7 @@ public class SetPathWebFilterFactoryTests {
 	}
 
 	private void testRewriteFilter(String template, String actualPath, String expectedPath, HashMap<String, String> variables) {
-		WebFilter filter = new SetPathWebFilterFactory().apply(new String[]{template});
+		WebFilter filter = new SetPathWebFilterFactory().apply(tuple().of(TEMPLATE_KEY, template));
 
 		MockServerHttpRequest request = MockServerHttpRequest
 				.get("http://localhost"+ actualPath)

spring-cloud-gateway-core/src/test/resources/application.yml

@@ -151,7 +151,8 @@ spring:
         - Path=/headers
         filters:
         - name: SetStatus
-          args: 401
+          args:
+            status: 401
 
       # =====================================
       - id: set_status_string_test