Spring WebClient使用

如下为一个使用了线程池，SSL，出现指定异常后充实，超时配置的demo

SSL配置

package com.demo.client;

import java.io.FileInputStream;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.PublicKey;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.function.Consumer;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SNIMatcher;
import javax.net.ssl.SNIServerName;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLParameters;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import reactor.netty.tcp.SslProvider.SslContextSpec;

public class SslConsumer implements Consumer<SslContextSpec> {

    private Logger logger = LoggerFactory.getLogger(SslConsumer.class);

    private String keyStorePath;
    private String password = "123456";
    private boolean trustServer = true;// 测试，默认为true
    private String serverCaPath = "";

    public SslConsumer(String keyStorePath) {
        this.keyStorePath = keyStorePath;
    }

    @Override
    public void accept(SslContextSpec t) {
        try {
            t.sslContext(createSslContext(loadKeyStore(keyStorePath))).handlerConfigurator(handler -> {

                SSLEngine engine = handler.engine();
                List<SNIMatcher> matchers = new LinkedList<SNIMatcher>();
                SNIMatcher matcher = new SNIMatcher(0) {
                    @Override
                    public boolean matches(SNIServerName serverName) {
                        // 返回true，不验证主机名
                        return true;
                    }
                };
                matchers.add(matcher);
                SSLParameters params = new SSLParameters();
                params.setSNIMatchers(matchers);
                engine.setSSLParameters(params);

            });
        } catch (Exception e) {

        }
    }

    private SslContext createSslContext(KeyStore keyStore) throws Exception {
        SslContextBuilder builder = SslContextBuilder.forClient();
        KeyManagerFactory keyMgrFactory = KeyManagerFactory.getInstance("SunX509");
        keyMgrFactory.init(keyStore, password.toCharArray());
        builder.keyManager(keyMgrFactory);

        SSLX509TrustMgr trustMgr = null;
        if (trustServer) {
            trustMgr = new SSLX509TrustMgr();
        } else {
            trustMgr = new SSLX509TrustMgr(getSeverPublicKey(serverCaPath));
        }
        builder.trustManager(trustMgr);

        List<String> ciper = new ArrayList<String>();
        ciper.add("TLS_RSA_WITH_AES_128_GCM_SHA256");
        ciper.add("TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256");
        ciper.add("TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256");

        builder.ciphers(ciper);
        return builder.build();
    }

    private KeyStore loadKeyStore(String keyStorePath) {
        KeyStore keyStore = null;
        InputStream in = null;
        try {
            in = new FileInputStream(keyStorePath);
            keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
            keyStore.load(in, password.toCharArray());

        } catch (Exception e) {
            logger.error("", e);
        }

        return keyStore;
    }

    private PublicKey getSeverPublicKey(String serverCaPath) {
        PublicKey key = null;
        InputStream in = null;
        try {
            in = new FileInputStream(serverCaPath);
            X509Certificate cert = (X509Certificate) CertificateFactory.getInstance("X.509").generateCertificate(in);
            key = cert.getPublicKey();
        } catch (Exception e) {
            logger.error("", e);
        }
        return key;
    }

}

验证服务器整数实现类

目前没有做任何处理，有需要验证服务器证书时，可以在对应的重写方法中进行处理

package com.demo.client;

import java.security.PublicKey;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

import javax.net.ssl.X509TrustManager;

public class SSLX509TrustMgr implements X509TrustManager {

    private PublicKey serverPublicKey;

    public SSLX509TrustMgr() {
        
    }
    public SSLX509TrustMgr(PublicKey serverPublicKey) {
        this.serverPublicKey = serverPublicKey;
    }

    @Override
    public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        // TODO Auto-generated method stub
        
    }

    @Override
    public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        // TODO Auto-generated method stub

    }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
        // TODO Auto-generated method stub
        return null;
    }

}

WebClient工具类

package com.demo.utils;


import java.net.ConnectException;
import java.net.NoRouteToHostException;
import java.time.Duration;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.MediaType;
import org.springframework.http.client.reactive.ReactorClientHttpConnector;
import org.springframework.web.reactive.function.client.WebClient;

import com.demo.entity.SslConsumer;

import io.netty.channel.ChannelOption;
import io.netty.channel.ConnectTimeoutException;
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.handler.timeout.WriteTimeoutHandler;
import reactor.core.publisher.Mono;
import reactor.netty.http.client.HttpClient;
import reactor.netty.resources.ConnectionProvider;
import reactor.netty.resources.LoopResources;
import reactor.netty.tcp.TcpClient;
import reactor.retry.Backoff;
import reactor.retry.Retry;

public class WebClientUtil {

    private static Logger logger = LoggerFactory.getLogger(WebClientUtil.class);
    private static Map<String, WebClient> webClientMap = new ConcurrentHashMap<String, WebClient>();

    public static WebClient createWebClient(String keyStorePath) {
        ConnectionProvider provider = ConnectionProvider.builder("wc-").maxConnections(30)
                .maxIdleTime(Duration.ofSeconds(30)).maxLifeTime(Duration.ofSeconds(30))
                .pendingAcquireTimeout(Duration.ofSeconds(30)).build();

        LoopResources loop = LoopResources.create("loop-", 20, 20, true);
        TcpClient tcpClient = TcpClient.create(provider).secure(new SslConsumer(keyStorePath)).runOn(loop)
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 2000).doOnConnected(conn -> conn
                        .addHandlerLast(new ReadTimeoutHandler(30)).addHandlerLast(new WriteTimeoutHandler(20)));
        return WebClient.builder().clientConnector(new ReactorClientHttpConnector(HttpClient.from(tcpClient))).build();

        // 如下方式可能会一直循环生成loop线程，直到程序僵死
//        HttpClient httpClient = HttpClient.create(provider).secure(new SslConsumer(keyStorePath))
//                .tcpConfiguration(client -> client.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000)
//                        .doOnConnected(con -> con.addHandlerLast(new ReadTimeoutHandler(20))
//                                .addHandlerLast(new WriteTimeoutHandler(10)))
//                        .runOn(LoopResources.create("loop-", 20, 20, true)));
//
//        return WebClient.builder().clientConnector(new ReactorClientHttpConnector(httpClient)).build();
    }

    public static Mono<String> doPost(String url, String data, String keyStorePath) {
        WebClient webClient = webClientMap.get(url);
        if (webClient == null) {
            webClient = createWebClient(keyStorePath);
            WebClient putIfAbsent = webClientMap.putIfAbsent(url, webClient);
            if (putIfAbsent != null) {
                webClient = putIfAbsent;
            }
        }

        Retry<?> retry = Retry.anyOf(ConnectTimeoutException.class, NoRouteToHostException.class).retryMax(3)
                .backoff(Backoff.fixed(Duration.ofMillis(100)));

        Mono<String> mono = webClient.post().uri(url).contentType(MediaType.APPLICATION_JSON).bodyValue(data).retrieve()
                .bodyToMono(String.class).timeout(Duration.ofSeconds(30)).doOnError(ConnectException.class, e -> {
                    logger.error("", e);
                }).doOnError(NoRouteToHostException.class, e -> {
                    logger.error("", e);
                }).retryWhen(retry);
        return mono;
    }

}

1、demo使用的springboot版本为2.3.3

2、HttpClient的create方法与secure方法不能分开，否则secure方法可能不生效

3、 ConnectionProvider中有很多方法已经过时，比如fixed，elastic，不建议使用，在过时的方法上，源码中也给出了对应替换使用的方法，比如fixed可以使用create方法替代，elastic方法可以用builder方法替代，但create方法直接创建的就为ConnectionProvider，重载的方法可以设置maxConnections，但不能设置连接最大空闲时间，连接最大生命周期等，builder方法可以对线程更精细的管理，故本例使用的builder方法和build来创建ConnectionProvider，如果使用默认的provider，线程数默认500，且maxIdleTime和maxLifeTime为-1

4、LoopResources为处理响应消息的线程数，2.3.3版本最小值为4

 

 5、ReactorClientHttpConnector存在一个重构方法

在该方法中，factory可以设置ConnectionProvider和LoopResources，mapper可以设置HttpClient，但在使用时可能是使用方式不正确，一直都是要么线程池配置上了，但SSL不可用，或者是SSL可用，但线程池不可用，后在ReactorClientHttpConnector两个参数的构造方法中看到initHttpClient方法，该方法中，使用了runOn配置LoopResources，故本例中也是用了runOn来配置。

测试：

@Override
    public void run(String... args) throws Exception {
        int count = 6;
        for (int i = 0; i < count; i++) {
            logger.info("start: {}", i);
            JsonObject obj = new JsonObject();
            obj.addProperty("name", "name"+i);
            obj.addProperty("age", i);
            Mono<String> mono = WebClientUtil.doPost(url, obj.toString(), keyStorePath);
            mono.subscribe(new MainConsumer(i));
            logger.info("end: {}", i);
        }
    }

    class MainConsumer implements Consumer<String> {
        private int i;

        public MainConsumer(int i) {
            this.i = i;
        }

        @Override
        public void accept(String t) {
            logger.info("receive: {}, loop: {}", t, i);
        }

    }

 结果：

[INFO] main 14:44:30 WebclientdemoApplication:61(logStarted) Started WebclientdemoApplication in 3.453 seconds (JVM running for 4.137)
[INFO] main 14:44:30 MainBusiStart:29(run) start: 0
[INFO] main 14:44:31 MainBusiStart:35(run) end: 0
[INFO] main 14:44:31 MainBusiStart:29(run) start: 1
[INFO] main 14:44:31 MainBusiStart:35(run) end: 1
[INFO] main 14:44:31 MainBusiStart:29(run) start: 2
[INFO] main 14:44:31 MainBusiStart:35(run) end: 2
[INFO] main 14:44:31 MainBusiStart:29(run) start: 3
[INFO] main 14:44:31 MainBusiStart:35(run) end: 3
[INFO] main 14:44:31 MainBusiStart:29(run) start: 4
[INFO] main 14:44:31 MainBusiStart:35(run) end: 4
[INFO] main 14:44:31 MainBusiStart:29(run) start: 5
[INFO] main 14:44:31 MainBusiStart:35(run) end: 5
[INFO] loop--nio-4 14:44:31 MainBusiStart:48(accept) receive: {"name":"name3","age":3.0}, loop: 3
[INFO] loop--nio-5 14:44:31 MainBusiStart:48(accept) receive: {"name":"name4","age":4.0}, loop: 4
[INFO] loop--nio-1 14:44:31 MainBusiStart:48(accept) receive: {"name":"name0","age":0.0}, loop: 0
[INFO] loop--nio-2 14:44:31 MainBusiStart:48(accept) receive: {"name":"name1","age":1.0}, loop: 1
[INFO] loop--nio-3 14:44:31 MainBusiStart:48(accept) receive: {"name":"name2","age":2.0}, loop: 2
[INFO] loop--nio-6 14:44:31 MainBusiStart:48(accept) receive: {"name":"name5","age":5.0}, loop: 5

 6、本例中，使用了一个reactor-extra进行重试处理

<dependency>
       <groupId>io.projectreactor.addons</groupId>
       <artifactId>reactor-extra</artifactId>
 </dependency>

但这种重试的方法虽然比较简单好用，但已经被标记为过时

应该使用传递一个reactor.util.retry.Retry类型参数的方法

 7、如果使用springclloud，则需要考虑springboot和springcloud的兼容问题，以及当前程序的springboot和springcloud版本与其他需要远程调用的版本的兼容