基于SpringCloudGateway实现微服务网关的方式

@Configuration
public class GatewayConfiguration {
    private final ServerProperties serverProperties;
    private final ApplicationContext applicationContext;
    private final ResourceProperties resourceProperties;
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;
 
    public GatewayConfiguration(ServerProperties serverProperties, ApplicationContext applicationContext, ResourceProperties resourceProperties, ObjectProvider<List<ViewResolver>> viewResolversProvider, ServerCodecConfigurer serverCodecConfigurer) {
        this.serverProperties = serverProperties;
        this.applicationContext = applicationContext;
        this.resourceProperties = resourceProperties;
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }
 
    @Bean("myErrorWebExceptionHandler")
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public ErrorWebExceptionHandler myErrorWebExceptionHandler(ErrorAttributes errorAttributes){
        MyErrorWebExceptionHandler exceptionHandler=new MyErrorWebExceptionHandler(
                errorAttributes,
                this.resourceProperties,
                this.serverProperties.getError(),
                this.applicationContext
        );
        exceptionHandler.setViewResolvers(this.viewResolvers);
        exceptionHandler.setMessageWriters(this.serverCodecConfigurer.getWriters());
        exceptionHandler.setMessageReaders(this.serverCodecConfigurer.getReaders());
        return exceptionHandler;
    }
}

spring:
  cloud:
    gateway:
      routes:
      - id: add_request_header_route
        uri: https://example.org
        filters:
        - AddRequestHeader=X-Request-red, blue

@Component
public class GatewayFilter implements GlobalFilter, Ordered {
    //在里面写过滤器的逻辑
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        System.out.println("进入了过滤器");
        //表示继续向下执行
        return chain.filter(exchange);
    }
    //过滤器的优先级，数值越小，优先级越高
    @Override
    public int getOrder() {
        return 0;
    }
}

@Component
public class GatewayFilter implements GlobalFilter, Ordered {
    //在里面写过滤器的逻辑
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        System.out.println("进入了过滤器");
        String token = exchange.getRequest().getQueryParams().getFirst("access-token");
        if (token==null){
            //如果不存在，认证失败
            System.out.println("没有登陆");
            exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);
            return exchange.getResponse().setComplete();
        }
        return chain.filter(exchange);
    }
    //过滤器的优先级，数值越小，优先级越高
    @Override
    public int getOrder() {
        return 0;
    }
}

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-spring-cloud-gateway-adapter</artifactId>
    <version>1.7.2</version>
</dependency>

spring:
  cloud:
    sentinel:
      eager: true
      transport:
        dashboard: localhost:8080

@Bean
@Order(-1)
public GlobalFilter sentinelGatewayFilter(){
    return new SentinelGatewayFilter();
}

@Configuration
public class GatewayConfiguration {
    private final ServerProperties serverProperties;
    private final ApplicationContext applicationContext;
    private final ResourceProperties resourceProperties;
    private final List<ViewResolver> viewResolvers;
    private final ServerCodecConfigurer serverCodecConfigurer;
 
    public GatewayConfiguration(ServerProperties serverProperties, ApplicationContext applicationContext, ResourceProperties resourceProperties, ObjectProvider<List<ViewResolver>> viewResolversProvider, ServerCodecConfigurer serverCodecConfigurer) {
        this.serverProperties = serverProperties;
        this.applicationContext = applicationContext;
        this.resourceProperties = resourceProperties;
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }
 
    //自定义一个错误处理
    @Bean(name = "myBlockRequestHandler")
    public BlockRequestHandler myBlockRequestHandler(){
        BlockRequestHandler blockRequestHandler=new BlockRequestHandler() {
            @Override
            public Mono<ServerResponse> handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
                return ServerResponse.status(HttpStatus.BAD_GATEWAY)
                        .contentType(MediaType.APPLICATION_jsON)
                        .body(BodyInserters.fromValue("服务被限流了"));
            }
        };
        return blockRequestHandler;
    }
 
    //用自定义的handler替换掉默认的，或者重定向
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler(BlockRequestHandler myBlockRequestHandler){
        //自定义Block处理
        GatewayCallbackManager.setBlockHandler(myBlockRequestHandler);
 
        //重定向block处理
        //GatewayCallbackManager.setBlockHandler(new RedirectBlockRequestHandler("http://www.baidu.com"));
        return new SentinelGatewayBlockExceptionHandler(viewResolvers,serverCodecConfigurer);
    }
 
    @Bean
    @Order(-1)
    public GlobalFilter sentinelGatewayFilter(){
        return new SentinelGatewayFilter();
    }
}

@Configuration
public class CorsConfig {
 
    @Bean
    public CorsWebFilter corsWebFilter(){
        CorsConfiguration configuration=new CorsConfiguration();
        configuration.addAllowedHeader("*");
        configuration.addAllowedMethod("*");
        configuration.addAllowedOrigin("*");
 
        UrlBasedCorsConfigurationSource source=new UrlBasedCorsConfigurationSource(new PathPatternParser());
        source.reGISterCorsConfiguration("/*",configuration);
        return new CorsWebFilter(source);
    }
}