java - 将 java 对象转换为 XML REST 响应

Question

我想在 API REST 调用后返回 XML 响应消息。我尝试了这个简单的测试:

@RestController
public class HelloWorldRestController {

    @Autowired
    ApiService apiService;
    @RequestMapping(value = "/api", method = RequestMethod.GET)
        public ResponseEntity<VisaResponse> listAllUsers() {
            VisaResponse obj = apiService.visaresponse();
            return new ResponseEntity<VisaResponse>(obj, HttpStatus.OK);
        }
    .......
}

我尝试将简单对象转换为 XML

public class VisaResponse {

    public VisaResponse() {
        jaxbObjectToXML(new VisaResponseHeader());
    }

    private static String jaxbObjectToXML(VisaResponseHeader customer) {
        String xmlString = "";
        try {
            JAXBContext context = JAXBContext.newInstance(VisaResponseHeader.class);
            Marshaller m = context.createMarshaller();

            m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE); // To format XML

            StringWriter sw = new StringWriter();
            m.marshal(customer, sw);
            xmlString = sw.toString();

        } catch (JAXBException e) {
            e.printStackTrace();
        }
        return xmlString;
    }
}

public class VisaResponseHeader {

    private int id;

    public VisaResponseHeader() {
        id = 3;
    }   
}

但是当我发出休息请求时，没有任何反应 - 没有任何响应。你知道我错在哪里吗？应返回简单内容。

Answer 1

1. 在@RequestMapping 中添加 Produces = "application/xml"。 @RequestMapping(value="/api", method=RequestMethod.GET, Produce=application/xml")
2. 您需要向您的 Bean 类 (VisaResponseHeader) 添加一些 JAXB 注释，以允许将其编码到 XML 中。

@XmlRootElement:此注释在顶级类中使用，用于指示 XML 文档中的根元素。注释中的 name 属性是可选的。如果未指定，则类名将用作文档中的根 XML 元素。

@XmlAttribute:该注解用于指示根元素的属性。

@XmlElement:此注释用于将成为根元素的子元素的类的属性。

HelloWorldRestController.java

@RestController
public class HelloWorldRestController {

    @Autowired
    ApiService apiService;

    @RequestMapping(value = "/api", method = RequestMethod.GET)
    public ResponseEntity<String> listAllUsers() {
        // get data from database
        VisaResponse visaResponse = apiService.visaresponse();

        // convert bean to XML
        String xmlResponse = jaxbObjectToXML(visaResponse);

        return new ResponseEntity<>(xmlResponse, HttpStatus.OK);
    }

    private static String jaxbObjectToXML(VisaResponse customer) {
        String xmlString = "";
        try {
            JAXBContext context = JAXBContext.newInstance(VisaResponse.class);
            Marshaller m = context.createMarshaller();

            m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
            StringWriter sw = new StringWriter();
            m.marshal(customer, sw);
            xmlString = sw.toString();
        } catch (JAXBException e) {
            e.printStackTrace();
        }
        return xmlString;
    }
}

VisaResponse.java

    @XmlRootElement
    @XmlAccessorType(XmlAccessType.FIELD)
    public class VisaResponse {

        @XmlElement
        private int id;

        // for testing purpose. Remove once database integration is done and data is received via service and repository.
        public VisaResponse() {
            id = 3;
        }
    }

不需要 VisaResponseHeader.java 类。

预期输出(使用Postman测试)