[BAEL-3311] Spring Cloud Gateway Routing Predicate Factories (#8549)

* [BAEL-3311] Spring Cloud Gateway Routing Predicate Factories

* [BAEL-3311] Code formatting

* [BAEL-3311] LiveTests

spring-cloud/spring-cloud-gateway/pom.xml

@@ -68,6 +68,10 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+        	<groupId>org.springframework.boot</groupId>
+        	<artifactId>spring-boot-devtools</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/custompredicates/CustomPredicatesApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.springcloudgateway.custompredicates;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+
+@SpringBootApplication
+public class CustomPredicatesApplication {
+
+    public static void main(String[] args) {
+        new SpringApplicationBuilder(CustomPredicatesApplication.class)
+          .profiles("customroutes")
+          .run(args);
+    }
+
+}

spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/custompredicates/config/CustomPredicatesConfig.java

@@ -0,0 +1,38 @@
+package com.baeldung.springcloudgateway.custompredicates.config;
+
+import org.springframework.cloud.gateway.filter.GatewayFilter;
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.baeldung.springcloudgateway.custompredicates.factories.GoldenCustomerRoutePredicateFactory;
+import com.baeldung.springcloudgateway.custompredicates.factories.GoldenCustomerRoutePredicateFactory.Config;
+import com.baeldung.springcloudgateway.custompredicates.service.GoldenCustomerService;
+
+@Configuration
+public class CustomPredicatesConfig {
+    
+    
+    @Bean
+    public GoldenCustomerRoutePredicateFactory goldenCustomer(GoldenCustomerService goldenCustomerService) {
+        return new GoldenCustomerRoutePredicateFactory(goldenCustomerService);
+    }
+    
+
+    //@Bean
+    public RouteLocator routes(RouteLocatorBuilder builder, GoldenCustomerRoutePredicateFactory gf ) {
+
+        return builder.routes()
+          .route("dsl_golden_route", r -> r.path("/dsl_api/**")
+            .filters(f -> f.stripPrefix(1))
+            .uri("https://httpbin.org")
+            .predicate(gf.apply(new Config(true, "customerId"))))
+          .route("dsl_common_route", r -> r.path("/dsl_api/**")
+            .filters(f -> f.stripPrefix(1))
+            .uri("https://httpbin.org")
+            .predicate(gf.apply(new Config(false, "customerId"))))             
+          .build();
+    }
+    
+}

spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/custompredicates/factories/GoldenCustomerRoutePredicateFactory.java

@@ -0,0 +1,102 @@
+/**
+ * 
+ */
+package com.baeldung.springcloudgateway.custompredicates.factories;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Predicate;
+
+import javax.validation.constraints.NotEmpty;
+
+import org.springframework.cloud.gateway.handler.predicate.AbstractRoutePredicateFactory;
+import org.springframework.http.HttpCookie;
+import org.springframework.validation.annotation.Validated;
+import org.springframework.web.server.ServerWebExchange;
+
+import com.baeldung.springcloudgateway.custompredicates.service.GoldenCustomerService;
+
+/**
+ * @author Philippe
+ *
+ */
+public class GoldenCustomerRoutePredicateFactory extends AbstractRoutePredicateFactory<GoldenCustomerRoutePredicateFactory.Config> {
+
+    private final GoldenCustomerService goldenCustomerService;
+    
+    public GoldenCustomerRoutePredicateFactory(GoldenCustomerService goldenCustomerService ) {
+        super(Config.class);
+        this.goldenCustomerService = goldenCustomerService;
+    }
+
+
+    @Override
+    public List<String> shortcutFieldOrder() {
+        return Arrays.asList("isGolden","customerIdCookie");
+    }
+
+
+    @Override
+    public Predicate<ServerWebExchange> apply(Config config) {
+        
+        return (ServerWebExchange t) -> {
+            List<HttpCookie> cookies = t.getRequest()
+              .getCookies()
+              .get(config.getCustomerIdCookie());
+              
+            boolean isGolden; 
+            if ( cookies == null || cookies.isEmpty()) {
+                isGolden = false;
+            }
+            else {                
+                String customerId = cookies.get(0).getValue();                
+                isGolden = goldenCustomerService.isGoldenCustomer(customerId);
+            }
+              
+            return config.isGolden()?isGolden:!isGolden;           
+        };
+    }
+    
+    
+    @Validated
+    public static class Config {        
+        boolean isGolden = true;
+        
+        @NotEmpty
+        String customerIdCookie = "customerId";
+        
+        
+        public Config() {}
+        
+        public Config( boolean isGolden, String customerIdCookie) {
+            this.isGolden = isGolden;
+            this.customerIdCookie = customerIdCookie;
+        }
+        
+        public boolean isGolden() {
+            return isGolden;
+        }
+        
+        public void setGolden(boolean value) {
+            this.isGolden = value;
+        }
+
+        /**
+         * @return the customerIdCookie
+         */
+        public String getCustomerIdCookie() {
+            return customerIdCookie;
+        }
+
+        /**
+         * @param customerIdCookie the customerIdCookie to set
+         */
+        public void setCustomerIdCookie(String customerIdCookie) {
+            this.customerIdCookie = customerIdCookie;
+        }
+        
+        
+        
+    }
+    
+}

spring-cloud/spring-cloud-gateway/src/main/java/com/baeldung/springcloudgateway/custompredicates/service/GoldenCustomerService.java

@@ -0,0 +1,26 @@
+/**
+ * 
+ */
+package com.baeldung.springcloudgateway.custompredicates.service;
+
+import org.springframework.stereotype.Component;
+
+/**
+ * @author Philippe
+ *
+ */
+@Component
+public class GoldenCustomerService {
+    
+    public boolean isGoldenCustomer(String customerId) {
+        
+        // TODO: Add some AI logic to check is this customer deserves a "golden" status ;^)
+        if ( "baeldung".equalsIgnoreCase(customerId)) {
+            return true;
+        }
+        else {
+            return false;
+        }
+    }
+
+}

spring-cloud/spring-cloud-gateway/src/main/resources/application-customroutes.yml

@@ -0,0 +1,26 @@
+spring:
+  cloud:
+    gateway:
+      routes:
+      - id: golden_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/api/**
+        - GoldenCustomer=true
+        filters:
+        - StripPrefix=1
+        - AddRequestHeader=GoldenCustomer,true
+      - id: common_route
+        uri: https://httpbin.org
+        predicates:
+        - Path=/api/**
+        - name: GoldenCustomer
+          args:
+            golden: false
+            customerIdCookie: customerId
+        filters:
+        - StripPrefix=1
+        - AddRequestHeader=GoldenCustomer,false
+        
+              
+        

spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/customfilters/gatewayapp/CustomFiltersLiveTest.java

@@ -5,6 +5,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 import org.assertj.core.api.Condition;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
 import org.springframework.boot.web.server.LocalServerPort;
@@ -27,6 +28,7 @@ public class CustomFiltersLiveTest {
     @LocalServerPort
     String port;
 
+    @Autowired
     private WebTestClient client;
 
     @BeforeEach

spring-cloud/spring-cloud-gateway/src/test/java/com/baeldung/springcloudgateway/custompredicates/CustomPredicatesApplicationLiveTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.springcloudgateway.custompredicates;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.net.URI;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.json.JSONTokener;
+import org.junit.Before;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.RequestEntity;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ActiveProfiles;
+
+/**
+ * This test requires
+ */
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+@ActiveProfiles("customroutes")
+public class CustomPredicatesApplicationLiveTest {
+
+    @LocalServerPort
+    String serverPort;
+    
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @Test
+    void givenNormalCustomer_whenCallHeadersApi_thenResponseForNormalCustomer() throws JSONException {
+
+        String url = "http://localhost:" + serverPort + "/api/headers";        
+        ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+        
+        JSONObject json = new JSONObject(response.getBody());
+        JSONObject headers = json.getJSONObject("headers");
+        assertThat(headers.getString("Goldencustomer")).isEqualTo("false");
+        
+    }
+
+    @Test
+    void givenGoldenCustomer_whenCallHeadersApi_thenResponseForGoldenCustomer() throws JSONException {
+
+        String url = "http://localhost:" + serverPort + "/api/headers";   
+        RequestEntity<Void> request = RequestEntity
+            .get(URI.create(url))
+            .header("Cookie", "customerId=baeldung")
+            .build();
+            
+        ResponseEntity<String> response = restTemplate.exchange(request, String.class);
+        assertThat(response.getStatusCode()).isEqualTo(HttpStatus.OK);
+        
+        JSONObject json = new JSONObject(response.getBody());
+        JSONObject headers = json.getJSONObject("headers");
+        assertThat(headers.getString("Goldencustomer")).isEqualTo("true");
+        
+    }
+    
+}