最简WebClient 同步、异步调用示例

目录

一，序言

WebClient是Spring WebFlux模块提供的一个非阻塞的基于响应式编程的进行Http请求的客户端工具，从Spring5.0开始WebClient作为RestTemplete的替代品，有更好的响应式能力，支持异步调用，可以在Spring项目中实现网络请求。

二，简单示例

1. 引入依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?><projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.fly</groupId><artifactId>web-client</artifactId><version>0.0.1</version><name>base</name><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><java.version>1.8</java.version><skipTests>true</skipTests></properties><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-webflux</artifactId><version>5.2.3.RELEASE</version></dependency><dependency><groupId>io.projectreactor.netty</groupId><artifactId>reactor-netty</artifactId><version>0.9.4.RELEASE</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.12.1</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.10</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version><scope>provided</scope></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.10.1</version><configuration><source>1.8</source><target>1.8</target><encoding>UTF-8</encoding></configuration></plugin></plugins></build></project>

2. 日志配置

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?><configurationstatus="off"monitorInterval="0"><appenders><consolename="Console"target="system_out"><patternLayoutpattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/></console></appenders><loggers><rootlevel="INFO"><appender-refref="Console"/></root></loggers></configuration>

3. 调用代码

FluxWebClient.java

importjava.nio.charset.StandardCharsets;importjava.util.ArrayList;importjava.util.Arrays;importjava.util.List;importjava.util.concurrent.atomic.AtomicInteger;importorg.apache.commons.lang3.RandomUtils;importorg.apache.commons.lang3.StringUtils;importorg.springframework.http.MediaType;importorg.springframework.web.reactive.function.client.WebClient;importlombok.extern.slf4j.Slf4j;/**
 * WebClient是RestTemplete的替代品，有更好的响应式能力，支持异步调用<br>
 * 
 * https://blog.csdn.net/zzhongcy/article/details/105412842
 * 
 */@Slf4jpublicclassFluxWebClient{privateList<String> urls =newArrayList<>();// 缓冲区默认256k，设为-1以解决报错Exceeded limit on max bytes to buffer : 262144privateWebClient webClient =WebClient.builder().codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)).build();publicvoidvisitAll(){// block转换为同步调用if(urls.isEmpty()){String resp = webClient.get().uri("https://00fly.online/upload/urls.txt").acceptCharset(StandardCharsets.UTF_8).accept(MediaType.TEXT_HTML).retrieve().bodyToMono(String.class).block();
            urls =Arrays.asList(StringUtils.split(resp,"\r\n"));
            log.info("★★★★★★★★ urls:");
            urls.stream().forEach(log::info);}// 异步访问AtomicInteger count =newAtomicInteger(0);
        urls.stream().filter(url ->RandomUtils.nextBoolean()).forEach(url -> webClient.get().uri(url).acceptCharset(StandardCharsets.UTF_8).accept(MediaType.TEXT_HTML).retrieve().bodyToMono(String.class).subscribe(r -> log.info("process complted: {}. {}", count.incrementAndGet(), url), e -> log.error(e.getMessage())));
        log.info("total:{} ==> ############## 异步请求已提交 ##############", urls.size());}}

RunMain.java

importjava.util.Timer;importjava.util.TimerTask;importlombok.extern.slf4j.Slf4j;@Slf4jpublicclassRunMain{/**
     * 程序运行入口
     * 
     * @param args
     */publicstaticvoidmain(String[] args){// Timer线程安全, 但单线程执行, 抛出异常时, task会终止FluxWebClient webClient =newFluxWebClient();newTimer().scheduleAtFixedRate(newTimerTask(){@Overridepublicvoidrun(){
                webClient.visitAll();}},0L,30*1000L);
        log.info("======== Timer started!");}}

4. 运行结果

三，完整代码

如何使用下面的备份文件恢复成原始的项目代码，请移步查阅：神奇代码恢复工具

//goto pom.xml<?xml version="1.0" encoding="UTF-8"?><project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.fly</groupId><artifactId>web-client</artifactId><version>0.0.1</version><name>web-client</name><packaging>jar</packaging><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding><java.version>1.8</java.version><skipTests>true</skipTests></properties><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-webflux</artifactId><version>5.2.3.RELEASE</version></dependency><dependency><groupId>io.projectreactor.netty</groupId><artifactId>reactor-netty</artifactId><version>0.9.4.RELEASE</version></dependency><dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-slf4j-impl</artifactId><version>2.12.1</version></dependency><dependency><groupId>org.apache.commons</groupId><artifactId>commons-lang3</artifactId><version>3.10</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version><scope>provided</scope></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.10.1</version><configuration><source>1.8</source><target>1.8</target><encoding>UTF-8</encoding></configuration></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-shade-plugin</artifactId><version>3.4.0</version><configuration><createDependencyReducedPom>false</createDependencyReducedPom></configuration><executions><execution><phase>package</phase><goals><goal>shade</goal></goals><configuration><minimizeJar>false</minimizeJar><filters><filter><artifact>*:*</artifact></filter></filters><transformers><!--
                                往MANIFEST文件中写入Main-Class是可执行包的必要条件。ManifestResourceTransformer可以轻松实现。 --><transformer
                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"><mainClass>com.fly.http.RunWebClient</mainClass></transformer></transformers></configuration></execution></executions></plugin></plugins></build></project>//goto src\main\java\com\fly\http\FluxWebClient.javapackagecom.fly.http;importjava.nio.charset.StandardCharsets;importjava.util.ArrayList;importjava.util.Arrays;importjava.util.List;importjava.util.concurrent.atomic.AtomicInteger;importorg.apache.commons.lang3.RandomUtils;importorg.apache.commons.lang3.StringUtils;importorg.springframework.http.MediaType;importorg.springframework.web.reactive.function.client.WebClient;importlombok.extern.slf4j.Slf4j;/**
 * WebClient是RestTemplete的替代品，有更好的响应式能力，支持异步调用<br>
 * 
 * https://blog.csdn.net/zzhongcy/article/details/105412842
 * 
 */@Slf4jpublicclassFluxWebClient{privateList<String> urls =newArrayList<>();// 缓冲区默认256k，设为-1以解决报错Exceeded limit on max bytes to buffer : 262144privateWebClient webClient =WebClient.builder().codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(-1)).build();publicvoidvisitAll(){// block转换为同步调用if(urls.isEmpty()){String resp = webClient.get().uri("https://00fly.online/upload/urls.txt").acceptCharset(StandardCharsets.UTF_8).accept(MediaType.TEXT_HTML).retrieve().bodyToMono(String.class).block();
            urls =Arrays.asList(StringUtils.split(resp,"\r\n"));
            log.info("★★★★★★★★ urls:");
            urls.stream().forEach(log::info);}// 异步访问AtomicInteger count =newAtomicInteger(0);
        urls.stream().filter(url ->RandomUtils.nextBoolean()).forEach(url -> webClient.get().uri(url).acceptCharset(StandardCharsets.UTF_8).accept(MediaType.TEXT_HTML).retrieve().bodyToMono(String.class).subscribe(r -> log.info("process complted: {}. {}", count.incrementAndGet(), url), e -> log.error(e.getMessage())));
        log.info("total:{} ==> ############## 异步请求已提交 ##############", urls.size());}}//goto src\main\java\com\fly\http\RunMain.javapackagecom.fly.http;importjava.util.Timer;importjava.util.TimerTask;importlombok.extern.slf4j.Slf4j;@Slf4jpublicclassRunMain{/**
     * 程序运行入口
     * 
     * @param args
     */publicstaticvoidmain(String[] args){// Timer线程安全, 但单线程执行, 抛出异常时, task会终止FluxWebClient webClient =newFluxWebClient();newTimer().scheduleAtFixedRate(newTimerTask(){@Overridepublicvoidrun(){
                webClient.visitAll();}},0L,30*1000L);
        log.info("======== Timer started!");}}//goto src\main\resources\log4j2.xml<?xml version="1.0" encoding="UTF-8"?><configuration status="off" monitorInterval="0"><appenders><console name="Console" target="system_out"><patternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/></console></appenders><loggers><root level="INFO"><appender-ref ref="Console"/></root></loggers></configuration>

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有任何问题和建议，都可以向我提问讨论,大家一起进步，谢谢!

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