Spring HATEOS：考虑在您的配置中定义类型为 'org.springframework.hateoas.config.HypermediaRestTemplateConfigurer' 的 bean

Question

我正在尝试使用 Spring HATEOS 库构建一个简单的 REST 客户端。

我在尝试使用 HypermediaRestTemplateConfigurer

注册我的 RestTemplate 时遇到以下异常

**************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of method hypermediaRestTemplateCustomizer in com.rest.client.config.RestClientConfiguraiton required a bean of type 'org.springframework.hateoas.config.HypermediaRestTemplateConfigurer' that could not be found.


Action:

Consider defining a bean of type 'org.springframework.hateoas.config.HypermediaRestTemplateConfigurer' in your configuration.

问题： 如何自己创建一个HypermediaRestTemplateConfigurer实例？我假设这个 class 会根据示例文档由 spring 引导自动配置？

我的代码：

主要class

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

    @SpringBootApplication
    public class RestClientApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(RestClientApplication .class, args);
        }
    
        @Bean
        public CommandLineRunner run(RestTemplate restTemplate) throws Exception {
            return args -> {
                String taskExecutionResources = restTemplate.getForObject(
                        "http://mydataflow-server.myhost.net/tasks/executions?name=task1225",
                        String.class);
                System.out.println(taskExecutionResources);
            };
        }
    
    }

配置class

import java.time.Duration;

import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.boot.web.client.RestTemplateCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.hateoas.config.HypermediaRestTemplateConfigurer;
import org.springframework.web.client.RestTemplate;

    @Configuration
    public class RestClientConfiguraiton {
    
        @Bean
        public RestTemplate restTemplate(RestTemplateBuilder builder) {
            return builder.setConnectTimeout(Duration.ofMinutes(5)).build();
        }
    
        @Bean
        public RestTemplateCustomizer hypermediaRestTemplateCustomizer(HypermediaRestTemplateConfigurer configurer) {
            return restTemplate -> {
                configurer.registerHypermediaTypes(restTemplate);
            };
        }
    
    }

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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.2</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.myapp</groupId>
    <artifactId>rest-client</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>rest-client</name>
    <description>Rest client for SCDF server</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-hateoas</artifactId>
            <exclusions>
                <exclusion>
                    <artifactId>tomcat-embed-el</artifactId>
                    <groupId>org.apache.tomcat.embed</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>tomcat-embed-core</artifactId>
                    <groupId>org.apache.tomcat.embed</groupId>
                </exclusion>
                <exclusion>
                    <artifactId>tomcat-embed-websocket</artifactId>
                    <groupId>org.apache.tomcat.embed</groupId>
                </exclusion>
            </exclusions>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Answer 1

解决方案是在我的 @Configuration 注释 class 上方使用 @EnableHypermediaSupport(type = HypermediaType.HAL)。（即 RestClientConfiguraiton class 在我的问题中显示）

幸运的是 HypermediaAutoConfiguration Java 文档中提到了这一点：

Auto-configuration for Spring HATEOAS's @EnableHypermediaSupport.

Spring HATEOS：考虑在您的配置中定义类型为 'org.springframework.hateoas.config.HypermediaRestTemplateConfigurer' 的 bean

Spring HATEOS : Consider defining a bean of type 'org.springframework.hateoas.config.HypermediaRestTemplateConfigurer' in your configuration

java

rest

resttemplate

spring-hateoas

spring-boot