SpringBoot请求工具http客户端

HTTP客户端请求工具

RestTemplate

在SpringBoot 中最常见的就是RestTemplate了

    public void test() {
    String forObject = restTemplate
            .getForObject("http://127.0.0.1:8999/hello", String.class);
}

简单的方式就可以快速请求工具了

OkHttp

<dependency>
    <groupId>com.squareup.okhttp3</groupId>
    <artifactId>okhttp</artifactId>
    <version>4.9.0</version>
</dependency>

常见的方法也适用

public void test() {
    OkHttpClient client = new OkHttpClient();

    Request request = new Request.Builder()
            .url("http://localhost:8080/api/v1/users")
            .build();
    Response response = client.newCall(request).execute();
}

不过在SpringBoot3新版本中被移除了

RestClient

RestClient是Spring6的产物,操作方式和RestTemplate差不多

public void test() {
    String body = restClient
            .get()
            .uri("http://127.0.0.1:8999/hello")
            .retrieve()
            .body(String.class);
}

WebClient

WebClient是在响应式框架中用到的客户端请求工具

• 需要先导入webflux包

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

public void test() {
    WebClient webClient = WebClient.builder().build();
    webClient
            .get()
            .uri("http://localhost:8080/hello")
            .retrieve().bodyToMono(String.class);
}

SpringBoot客户端请求方式

在新版SpringBoot中可以安装OpenFein的方式封装接口

HttpApiConfig.java

@Configuration
public class HttpApiConfig {
    @Bean
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    @Bean
    public RestClient restClient() {
        return RestClient.builder()
                .build();
    }

    @Bean
    public WebClient webClient() {
        WebClient webClient = WebClient.builder().build();
        webClient.get().uri("http://localhost:8080/hello").retrieve().bodyToMono(String.class);
        return WebClient
                .builder()
                .build();
    }

    @Bean
    public RemoteApi restTemplateRemoteApi(RestTemplate restTemplate) {
        return HttpServiceProxyFactory
                .builderFor(RestTemplateAdapter
                        .create(restTemplate))
                .build()
                .createClient(RemoteApi.class);
    }

    @Bean
    public RemoteApi restClientRemoteApi(RestClient restClient) {
        return HttpServiceProxyFactory
                .builderFor(RestClientAdapter.create(restClient))
                .build()
                .createClient(RemoteApi.class);
    }

    @Bean
    public RemoteApi webClientRemoteApi(WebClient webClient) {
        return HttpServiceProxyFactory
                .builderFor(WebClientAdapter.create(webClient))
                .build()
                .createClient(RemoteApi.class);
    }
}

封装客户端请求接口

@HttpExchange("http://locallhost:8999")
public interface RemoteApi {
    @GetExchange("/hello")
    String hello();

    @PostExchange("/hello")
    String postHello();

    @PutExchange("/hello")
    String putHello();

    @DeleteExchange("/hello")
    String deleteHello();
    // ...
}

@Resource
private RemoteApi restClientRemoteApi;

@Test
public void testRemoteApi() {
    String hello = restClientRemoteApi.hello();
}

这样写起来的客户端请求更加优雅