Micronaut 使用 ProxyHttpClient 代理請求

import io.micronaut.core.async.publisher.Publishers;
import io.micronaut.core.util.StringUtils;
import io.micronaut.http.HttpRequest;
import io.micronaut.http.MutableHttpResponse;
import io.micronaut.http.annotation.Filter;
import io.micronaut.http.client.ProxyHttpClient;
import io.micronaut.http.filter.HttpServerFilter;
import io.micronaut.http.filter.ServerFilterChain;
import io.micronaut.runtime.server.EmbeddedServer;
import org.reactivestreams.Publisher;

@Filter("/proxy/**")
public class ProxyFilter implements HttpServerFilter { // (1)

    private final ProxyHttpClient client;
    private final EmbeddedServer embeddedServer;

    public ProxyFilter(ProxyHttpClient client,
                       EmbeddedServer embeddedServer) { // (2)
        this.client = client;
        this.embeddedServer = embeddedServer;
    }

    @Override
    public Publisher<MutableHttpResponse<?>> doFilter(HttpRequest<?> request,
                                                      ServerFilterChain chain) {
        return Publishers.map(client.proxy( // (3)
                request.mutate() // (4)
                        .uri(b -> b // (5)
                                .scheme("http")
                                .host(embeddedServer.getHost())
                                .port(embeddedServer.getPort())
                                .replacePath(StringUtils.prependUri(
                                        "/real",
                                        request.getPath().substring("/proxy".length())
                                ))
                        )
                        .header("X-My-Request-Header", "XXX") // (6)
        ), response -> response.header("X-My-Response-Header", "YYY"));
    }
}

import io.micronaut.core.async.publisher.Publishers
import io.micronaut.core.util.StringUtils
import io.micronaut.http.HttpRequest
import io.micronaut.http.MutableHttpResponse
import io.micronaut.http.annotation.Filter
import io.micronaut.http.client.ProxyHttpClient
import io.micronaut.http.filter.HttpServerFilter
import io.micronaut.http.filter.ServerFilterChain
import io.micronaut.http.uri.UriBuilder
import io.micronaut.runtime.server.EmbeddedServer
import org.reactivestreams.Publisher

@Filter("/proxy/**")
class ProxyFilter implements HttpServerFilter { // (1)

    private final ProxyHttpClient client
    private final EmbeddedServer embeddedServer

    ProxyFilter(ProxyHttpClient client,
                EmbeddedServer embeddedServer) { // (2)
        this.client = client
        this.embeddedServer = embeddedServer
    }

    @Override
    Publisher<MutableHttpResponse<?>> doFilter(HttpRequest<?> request,
                                               ServerFilterChain chain) {
        Publishers.map(client.proxy( // (3)
                request.mutate() // (4)
                        .uri { UriBuilder b -> // (5)
                            b.with {
                                scheme("http")
                                host(embeddedServer.host)
                                port(embeddedServer.port)
                                replacePath(StringUtils.prependUri(
                                        "/real",
                                        request.path.substring("/proxy".length())
                                ))
                            }
                        }
                        .header("X-My-Request-Header", "XXX") // (6)
        ), { it.header("X-My-Response-Header", "YYY") })
    }
}

import io.micronaut.core.async.publisher.Publishers
import io.micronaut.core.util.StringUtils
import io.micronaut.http.HttpRequest
import io.micronaut.http.MutableHttpResponse
import io.micronaut.http.annotation.Filter
import io.micronaut.http.client.ProxyHttpClient
import io.micronaut.http.filter.HttpServerFilter
import io.micronaut.http.filter.ServerFilterChain
import io.micronaut.http.uri.UriBuilder
import io.micronaut.runtime.server.EmbeddedServer
import org.reactivestreams.Publisher

@Filter("/proxy/**")
class ProxyFilter(
    private val client: ProxyHttpClient, // (2)
    private val embeddedServer: EmbeddedServer
) : HttpServerFilter { // (1)

    override fun doFilter(request: HttpRequest<*>,
                          chain: ServerFilterChain): Publisher<MutableHttpResponse<*>> {
        return Publishers.map(client.proxy( // (3)
            request.mutate() // (4)
                .uri { b: UriBuilder -> // (5)
                    b.apply {
                        scheme("http")
                        host(embeddedServer.host)
                        port(embeddedServer.port)
                        replacePath(StringUtils.prependUri(
                            "/real",
                            request.path.substring("/proxy".length))
                        )
                    }
                }
                .header("X-My-Request-Header", "XXX") // (6)
        ), { response: MutableHttpResponse<*> -> response.header("X-My-Response-Header", "YYY") })
    }
}