SpringBoot：远程调用异步化

超、凢脫俗 2022-12-31 03:24 115阅读 0赞

*  AsyncRestTemplate

想使用AsyncRestTemplate，首先得对其进行注入

@Bean
    public AsyncRestTemplate asyncRestTemplate(){ 
        return new AsyncRestTemplate();
    }

然后我们新建一个controller进行测试

@Autowired
    private AsyncRestTemplate asyncRestTemplate;
    
    @GetMapping("/test-async-rest-template")
    public String testAsyncRestTemplate() { 
    
    	// 这里使用了一个本地请求，模拟远程请求
        ListenableFuture<ResponseEntity<ResponseModel>> future = this.asyncRestTemplate.getForEntity(
            "http://localhost:8088/path",
                ResponseModel.class,
            1
        );
        
        // 会阻塞的回调方式
        // ResponseEntity<ResponseModel> entity = future.get();
        // ResponseModel body = entity.getBody();
    
        // 不会阻塞的回调方式
        future.addCallback(new ListenableFutureCallback<ResponseEntity<ResponseModel>>() { 
            @Override
            public void onFailure(Throwable ex) { 
                log.error("请求失败", ex);
            }
    
            @Override
            public void onSuccess(ResponseEntity<ResponseModel> result) { 
                log.info("调用成功,body = {}", result.getBody().getData());
            }
        });
        return "success";
    }

上面的demo使用了get请求，如果想使用post请求，使用以下方式即可：

this.asyncRestTemplate.postForEntity(
                "http://localhost:8088/path",
                new HttpEntity<>(RequestModel),
                ResponseModel.class
            );

`AsyncRestTemplate`的使用还是比较简单的，但是spring 5.0后已经弃用了，官方文档中写明了在5.0之后建议使用`WebClient`

*  WebClient

使用WebClient要先添加两个依赖

<dependency>
    	<groupId>org.springframework</groupId>
    	<artifactId>spring-webflux</artifactId>
    </dependency>
    
    <dependency>
    	<groupId>io.projectreactor.netty</groupId>
    	<artifactId>reactor-netty</artifactId>
    </dependency>

也需要先注入

@Bean
    public WebClient webClient(){ 
        return WebClient.create();
    }

它的使用与AsyncRestTemplate类似

@Autowired
    privateWebClient webClient;
    
    @GetMapping("/test-web-client")
    public ResponseModel testWebClient() { 
        Mono<ResponseModel> mono = this.webClient.get()
            .uri("http://localhost:8088/path", 1)
            .retrieve()
            .bodyToMono(ResponseModel.class);
    
        return mono.block();
    }
    
    
    @GetMapping("/test-web-client-post")
    public ResponseModel testWebClientPost() { 
    
        return this.webClient.post()
            .uri("http://localhost:8088/path")
            // 指定发送请求时候的content-type 这个header的值
            .contentType(MediaType.APPLICATION_JSON)
            .body(BodyInserters.fromObject(RequestModel))
            .retrieve()
            .bodyToMono(ResponseModel.class)
            .block();
    }

更多使用方法可参考[《WebClient官方文档》][WebClient]

[WebClient]: https://docs.spring.io/spring-framework/docs/current/reference/html/web-reactive.html#webflux-client