Question

我正在尝试使用本教程使用RESTful Web Service： Consuming a RESTful Web Service

然而，当调用restTemplate时，我得到以下错误

org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class [cukamart.cvut.fel.cz.dto.Flight;] and content type [text/html;charset=UTF-8]

我不明白为什么内容类型设置为 text / html 。它应该是 application / json ，因为我将 jackson 依赖项添加到我的pom.xml中，而spring-boot应该为我配置它吗？

因为Jackson JSON处理库在类路径中，所以RestTemplate将使用它（通过消息转换器）来转换传入的JSON数据

这是我的restTemplate bean

@Configuration
public class AosClientConfig extends WebMvcConfigurerAdapter{

    @Bean
    public RestTemplate restTemplate(RestTemplateBuilder builder) {
        return builder.build();
    }
}

带有jackson依赖性的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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cukamart.cvut.fel.cz</groupId>
    <artifactId>aosclient</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>aosclient</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.3.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
</dependencies>

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

尝试使用RESTful Web服务的控制器

@Controller
@RequestMapping(value = "/flight")
public class FlightController {

    @Value("${endpoint.url}")
    private String url;

    @Autowired
    private RestTemplate restTemplate;

    @GetMapping(value = "/preview")
    public String showAllFlights() {

        restTemplate.getForObject(url,  Flight[].class); //throw exception

        ....
        return "flights";
    }
}

知道我做错了什么或如何告诉restTemplate使用内容类型的应用程序/ json？

我也试过这个，但我得到了同样的错误

@GetMapping(value = "/preview")
    public String showAllFlights() {
        HttpHeaders headers = new HttpHeaders();
        headers.setAccept(Collections.singletonList(MediaType.APPLICATION_JSON));

        HttpEntity<String> entity = new HttpEntity<String>("parameters", headers);

        restTemplate.exchange(url, HttpMethod.GET, entity, Flight[].class);

        return "flights";
    }

Answer 1

它看起来像＆＃34; Content-Type＆＃34;未设置响应中的标头。您可以使用Postman（Chrome扩展程序）或类似的REST客户端向该网址发送请求吗？这将帮助您查看REST端点是否实际使用＆＃34; Content-Type：application / json＆＃34;响应标题。

http://blog.getpostman.com/2015/06/13/debugging-postman-requests/说明了如何使用Postman检查响应标头。

Answer 2

我认为问题可能出在此行上：

restTemplate.exchange(url, HttpMethod.GET, entity, Flight[].class);

当httpmethod是GET时，resttemplate会忽略主体，因此不会包含您的实体。将httpmethod更改为POST，然后查看目标服务是否接收到有效负载。如果控制它，则可能必须更改目标服务才能使其接受POST。

Spring Boot - 为内容类型application / json配置restTemplate

2 个答案: