Spring RestController返回错误的内容类型

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        configurer.defaultContentType(MediaType.APPLICATION_JSON);
    }
}

@RestController
public class ExampleController {

    @GetMapping(value = "/example", produces = MediaType.APPLICATION_JSON_VALUE)
    public ExampleResponse getExample() {
        return new ExampleResponse();
    }
}

@RestController
public class ExampleController {

    @Autowired
    private ExampleService exampleService;

    @GetMapping(value = "/example", produces = MediaType.APPLICATION_JSON_VALUE)
    public ExampleResponse getExample() {
        ExampleResponse response = exampleService.getExample();
        return new ExampleResponseAdapter(response);
    }
}

class ExampleResponseAdapter {
    private ExampleResponse response;

    public ExampleResponseAdapter(ExampleResponse response) {
        this.response = response;
    }

    // 自定义 getter 和 setter 方法
}