server:
  server-name: gatewaymvcdemo
  port: 8888
spring:
  profiles:
    active: javaconfig

package com.mrhan.config;
import com.mrhan.service.GatewayHandler;
import com.mrhan.service.UserHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.web.servlet.function.*;
import java.time.ZonedDateTime;
import java.util.function.BiFunction;
import java.util.function.Function;
import static org.springframework.cloud.gateway.server.mvc.filter.BeforeFilterFunctions.*;
import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;
import static org.springframework.cloud.gateway.server.mvc.predicate.GatewayRequestPredicates.*;
import static org.springframework.web.servlet.function.RequestPredicates.accept;
/**
 * @author Mr han
 * @date 2025/12/6
 * @description 路由配置，此處配置了路由后，application.yml中配置的路由將無(wú)效，兩種配置只能存在一種，不能并存
 * 同等效果配置文件方式配置@see application.yml,自定義的filter和predicate在兩種配置方式都能夠生效
 *
 *
*/
@Configuration(proxyBeanMethods = false)
@Profile("javaconfig")
public class ApplicationRoutingConfig {
    private static final Logger log = LoggerFactory.getLogger(ApplicationRoutingConfig.class);
    /**
     *
     * @return
     * @date 2025/12/17
     * @description 使用java代碼方式配置路由，等價(jià)于@see application.yml文件配置方式
     *
     */
    @Bean
    public RouterFunction<ServerResponse> customRoutes(GatewayHandler gatewayHandler) {
        // @formatter:off
        return route("path_route")
                .GET("/gateway/getRole", accept(MediaType.TEXT_HTML),gatewayHandler::getRole)
                .POST("/gateway/updateRole/{roleId}", accept(MediaType.APPLICATION_JSON), gatewayHandler::updateRole)
                .before(request -> {
                    String path = request.requestPath().value();
                    log.error("=========開(kāi)始進(jìn)入本服務(wù)請(qǐng)求：{}=========",path);
                    return request;
                })
                // 添加請(qǐng)求之后的函數(shù)處理器
                .after((request,response) -> {
                    log.error("==========本服務(wù)請(qǐng)求處理完畢：{}，響應(yīng)的狀態(tài)碼：",request.requestPath().value(),response.statusCode());
                    return response;
                })
                .build().and(route("entitle_route")
                    .route(path("/entitleservice/**").and(SampleRequestPredicates.predicateHeaderExists("entitle_header")), http())
                    .before(uri("http://localhost:8081"))
                    .before(addRequestParameter("code","Java gateway for entitlementservice"))
                    .before(addRequestHeader("java_config_header","java config value"))
                    .filter(SampleHandlerFilterFunctions.instrumentForFilter("req_header","rep_header"))
                .build().and(route("function_demo_route")
                    .route(path("/functionservletpath/**").and(SampleRequestPredicates.predicateHeaderExists("function_header")), http())
                    .before(uri("http://localhost:8082"))
                    .before(addRequestParameter("code","Java config gateway for functiondemo"))
                    .before(addRequestHeader("function-Request-Id","function_header_value"))
                .build()));
    }
    /**
     * @author Mr han
     * @date 2025/12/15
     * @description 自定義的predicate 是否包含某個(gè)固定的請(qǐng)求頭，此類(lèi)的實(shí)現(xiàn)等等同于方法 @see {@link SampleRequestPredicates#predicateHeaderExists(String)}
     *
    */
    private static class CustomHeaderExists implements RequestPredicate {
        // 請(qǐng)求頭名稱(chēng)
        private static final String HEADER_NAME = "custom_header";
        /**
         *
         * @return
         * @date 2025/12/15
         * @description 需要包含custom_header請(qǐng)求頭
         *
         */
        @Override
        public boolean test(ServerRequest request) {
            return request.headers().asHttpHeaders().containsKey(HEADER_NAME);
        }
    }
    /**
     *
     * @return
     * @date 2025/12/15
     * @description 使用函數(shù)式的方法，自定義過(guò)濾器，使用函數(shù)式方法實(shí)現(xiàn)過(guò)濾器
     * 在自定義的過(guò)濾器中可以實(shí)現(xiàn)日志的打印，已經(jīng)權(quán)限的認(rèn)證等邏輯，這里僅僅是增加請(qǐng)求頭及響應(yīng)頭
     * 此方法等同于@see {@link SampleHandlerFilterFunctions#instrumentForFilter(String, String)}
     *
     */
    private static HandlerFilterFunction<ServerResponse, ServerResponse> instrumentWithFilter(String requestHeader,String responseHeader){
        return (request,next) -> {
            ServerRequest modifier = ServerRequest.from(request).header(requestHeader, "hello").build();
            ServerResponse responseHandler = next.handle(modifier);
            responseHandler.headers().add(responseHeader, "world");
            return responseHandler;
        };
    }
    /**
     *
     * @return
     * @date 2025/12/15
     * @description 使用函數(shù)式的方法，定義before方式的過(guò)濾器
     *
     */
    private static Function<ServerRequest, ServerRequest> instrumentWithBefore(String requestHeader){
        return request -> {
            return ServerRequest.from(request).header(requestHeader, "before_header_value").build();
        };
    }
    /**
     *
     * @return
     * @date 2025/12/15
     * @description 使用函數(shù)式的方法，定義after方式的過(guò)濾器
     *
     */
    private static BiFunction<ServerRequest, ServerResponse, ServerResponse> instrumentWithAfter(String header){
        return (request,response) -> {
            response.headers().add(header, "after_header_value");
            return response;
        };
    }
}

package com.mrhan.config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.server.mvc.common.Configurable;
import org.springframework.cloud.gateway.server.mvc.common.Shortcut;
import org.springframework.util.StringUtils;
import org.springframework.web.servlet.function.HandlerFilterFunction;
import org.springframework.web.servlet.function.ServerRequest;
import org.springframework.web.servlet.function.ServerResponse;
import java.util.Objects;
import java.util.function.Function;
/**
 * @author Mr han
 * @date 2025/12/15
 * @description 定義包含所有自定義filter的函數(shù)式過(guò)濾器類(lèi),供filtersupplier類(lèi)使用暴露到項(xiàng)目中
 * 一個(gè)類(lèi)只能定義一個(gè)靜態(tài)方法，spring cloud gateway只注冊(cè)一個(gè)靜態(tài)方法
 */
public class SampleHandlerFilterFunctions {
    private static final Logger log = LoggerFactory.getLogger(SampleHandlerFilterFunctions.class);
    @Shortcut
    public static HandlerFilterFunction<ServerResponse, ServerResponse> instrumentForFilter(String reqHeaderName,String repHeaderName) {
        return (request, next) -> {
            log.error("==========進(jìn)入自定義filter處理邏輯，請(qǐng)求頭：{},響應(yīng)頭{}===========",reqHeaderName,repHeaderName);
            ServerRequest modified = ServerRequest.from(request)
                    .header(reqHeaderName, "request header for filter").build();
            ServerResponse response = next.handle(modified);
            response.headers().add(repHeaderName,"response header for filter" );
            return response;
        };
    }

package com.mrhan.config;
import org.springframework.cloud.gateway.server.mvc.filter.SimpleFilterSupplier;
/**
 * @author Mr han
 * @date 2025/12/15
 * @description 創(chuàng)建字對(duì)應(yīng)的filterSupplier，用于注冊(cè)提供自定義的filter
 */
public class CustomFilterSupplier extends SimpleFilterSupplier {
    public CustomFilterSupplier() {
        super(SampleHandlerFilterFunctions.class);
    }
}

package com.mrhan.config;
import jakarta.annotation.PostConstruct;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
/**
 * @author Mr han
 * @date 2025/12/17
 * @description 注冊(cè)自定義的過(guò)濾器，用于配置在application.yml文件中，目前使用此配置方式無(wú)實(shí)際效果 TODO
*/
@Configuration
@Profile("fileconfig")
public class FilterConfiguration {
    private static final Logger log = LoggerFactory.getLogger(FilterConfiguration.class);
    @PostConstruct
    public void init(){
        log.error("========開(kāi)始加載FilterConfiguration配置============");
    }
    @Bean
    public CustomFilterSupplier customFilterSupplier() {
        return new CustomFilterSupplier();
    }
}

package com.mrhan.config;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.server.mvc.common.Configurable;
import org.springframework.cloud.gateway.server.mvc.common.Shortcut;
import org.springframework.web.servlet.function.RequestPredicate;
/**
 * @author Mr han
 * @date 2025/12/15
 * @description 定義包含自定義Predicate的所有實(shí)現(xiàn)的類(lèi)
 */
public class SampleRequestPredicates {
    private static final Logger log = LoggerFactory.getLogger(SampleRequestPredicates.class);
    /**
     *
     * @return
     * @date 2025/12/15
     * @description 請(qǐng)求頭的判斷（是否包含某個(gè)名稱(chēng)的請(qǐng)求頭）,必須添加@Configurable注解且只能有一個(gè)參數(shù)，不然無(wú)法生效
     *
     */
    @Shortcut
    public static RequestPredicate predicateHeaderExists(String name) {
        log.error("======進(jìn)入了自定義predicate的處理邏輯所需請(qǐng)求頭：{}==========",name);
        return request -> {
            return request.headers().asHttpHeaders().containsKey(name);
        };
    }
}

package com.mrhan.config;
import org.springframework.cloud.gateway.server.mvc.predicate.PredicateSupplier;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collection;
public class CustomPredicateSupplier implements PredicateSupplier {
    @Override
    public Collection<Method> get() {
        return Arrays.asList(SampleRequestPredicates.class.getMethods());
    }
}

package com.mrhan.config;
import jakarta.annotation.PostConstruct;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.cloud.gateway.server.mvc.predicate.PredicateSupplier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Profile;
/**
 * @author Mr han
 * @date 2025/12/17
 * @description 注冊(cè)自定義的predicate，用在application.yml中
*/
@Configuration
@Profile("fileconfig")
public class PredicateConfiguration {
    private static final Logger log = LoggerFactory.getLogger(PredicateConfiguration.class);
    @PostConstruct
    public void init(){
        log.error("========開(kāi)始加載PredicateConfiguration配置============");
    }
    @Bean
    public CustomPredicateSupplier customPredicateSupplier() {
        return new CustomPredicateSupplier();
    }
}