Java Topics
HubJava Collections FrameworkCollections Practice ProgramsComparable vs ComparatorGenericsIteratorArrayListLinkedListStackVectorHashMapHashtableLinkedHashMapTreeMapArrayDequeDeque Double-Ended QueuePriorityQueueHashSetLinkedHashSetTreeSetAdapter PatternBuilder PatternFactory PatternMVC PatternObserver PatternSingleton PatternDynamic ProgrammingGraphHashingHeapLinked List DSAQueue DSARecursionSearching AlgorithmsSorting AlgorithmsStack DSATime ComplexityTreesException Handling Best PracticesCustom ExceptionException Hierarchyfinally BlockException Handlingthrow aur throwstry-catchBuffered StreamsByte StreamsCharacter StreamsDeserializationFile ClassJava NIO New I/OSerializationArrays in JavaArray OperationsArray Practice ProgramsArray Interview QuestionsJagged ArrayMulti-Dimensional ArraysOne Dimensional Arraybreak aur continuedo-while Loopfor Loopif-else StatementsNested Loopsswitch-case Statementwhile LoopJava Compilation ProcessJava ki FeaturesPehla Java ProgramHistory of JavaJava EditionsJava Program StructureJDK, JRE aur JVMJava Kya Hai?Immutable StringsString Class in JavaString Interview QuestionsString MethodsString Practice ProgramsStringBufferStringBuilderComments in JavaData Types in JavaIdentifiers in JavaInput & Output in JavaJava KeywordsOperators in JavaType Casting in JavaVariables in JavaJava Coding Interview QuestionsCollections Interview QuestionsCore Java Interview QuestionsJDBC Interview QuestionsMultithreading Interview QuestionsOOPs Interview QuestionsSpring Framework Interview QuestionsJava 8 Date/Time APIDefault aur Static Methods in InterfaceFunctional InterfaceLambda ExpressionMethod ReferenceOptional ClassStream APIBatch ProcessingCallableStatementJDBC ArchitectureJDBC — Java Database ConnectivityJDBC Practice ProjectsMySQL ConnectionPreparedStatementResultSetStatement InterfaceTransaction ManagementCreating ThreadsDaemon ThreadExecutor FrameworkInter-Thread CommunicationMultithreading Practice ProgramsRunnable InterfaceSynchronizationThread ClassMultithreading IntroductionThread Life CycleThread PriorityJava Cheat SheetImportant Formulas & Key ConceptsImportant Java ProgramsJava Quick RevisionAbstract ClassAbstractionAnonymous ClassClass and ObjectConstructorEncapsulationInheritanceInner ClassInterfaceMethod OverloadingMethod OverridingObject ClassObject CloningObject-Oriented Programming OOPPolymorphismstatic Keywordsuper Keywordthis KeywordWrapper ClassesArray Practice ProgramsBasic Java Practice ProgramsCollection Practice ProgramsJDBC Practice ProgramsMultithreading Practice ProgramsOOPs Practice ProgramsPlacement Coding QuestionsString Practice ProgramsBanking SystemChat ApplicationE-Commerce Backend — Spring Boot REST APIEmployee Management SystemLibrary Management SystemSpring Boot Fullstack ProjectStudent Management SystemCookies in ServletExpression Language ELGenericServletHttpServletJavaServer Pages JSPJSP TagsMVC ArchitectureHttpServletRequest & HttpServletResponseServlet IntroductionServlet Life CycleSession TrackingDependency InjectionSpring BeansSpring CoreSpring FrameworkAPI GatewaySpring Cloud Config ServerDocker DeploymentEureka Server — Service DiscoverySpring Boot CRUD ApplicationException Handling in Spring BootJWT AuthenticationREST API in Spring BootSpring SecuritySpring BootSpring Data JPAValidation in Spring Boot
API Gateway
Last Updated : 26 May, 2026
title: API Gateway - Spring Cloud Gateway
Spring Framework29 words3 headingsExamples included
title: API Gateway - Spring Cloud Gateway description: Microservices mein API Gateway setup
Single entry point for all microservices. Routing, load balancing, security.
Dependency
xml exampleWoHoTech
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>application.yml
yaml exampleWoHoTech
spring:
cloud:
gateway:
routes:
- id: user-service
uri: lb://USER-SERVICE
predicates:
- Path=/api/users/**
filters:
- StripPrefix=1
- AddRequestHeader=X-Gateway-Source, api-gateway
- id: order-service
uri: lb://ORDER-SERVICE
predicates:
- Path=/api/orders/**
- Method=GET,POST
- id: product-service
uri: http://localhost:8083
predicates:
- Path=/api/products/**Custom Filter
@Component
public class AuthenticationFilter implements GlobalFilter, Ordered {
@Autowired JwtUtils jwtUtils;
@Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
String token = exchange.getRequest().getHeaders().getFirst("Authorization");
if (token == null || !token.startsWith("Bearer ")) {
exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
return exchange.getResponse().setComplete();
}
// Validate token
return chain.filter(exchange);
}
@Override
public int getOrder() { return -1; }
}
Exam Focus
Revise definitions, diagrams, examples, and short-answer points for API Gateway.
Interview Use
Prepare one clear explanation, one practical example, and one common mistake for this Java topic.
Search Terms
java, java programming, core java, java master course, java notes, master, course, spring
Related Java Topics
Continue learning this concept
Spring FrameworkSpring Cloud Config Servertitle: Config Server - Spring Cloud ConfigSpring FrameworkDocker Deploymenttitle: Docker DeploymentSpring FrameworkEureka Server — Service Discoverytitle: Eureka Server - Service DiscoverySpring FrameworkREST API in Spring Boottitle: REST API with Spring BootSpring FrameworkDependency Injectiontitle: Dependency Injection in SpringSpring FrameworkSpring Beanstitle: Spring Beans