将 java 对象转换为 XML REST 响应

Question

我想在 API REST 调用后 return 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;
    }   
}

但是当我提出休息请求时没有任何反应 - 没有任何回应。你知道我哪里错了吗？简单的内容应该 returned.

Answer 1

在@RequestMapping 中添加produces = "application/xml"。 @RequestMapping(value="/api", method=RequestMethod.GET, produces=application/xml")
您需要将 JAXB 注释 添加到您的 bean class (VisaResponseHeader) 以允许它被编组进入 XML。

@XmlRootElement: 这个注解用在顶层 class 表示 XML 文档中的根元素。注释中的名称属性是可选的。如果未指定，class 名称将用作文档中的根 XML 元素。

@XmlAttribute:这个注解用来表示根元素的属性。

@XmlElement: 此注释用于 class 的属性，它将成为根元素的子元素。

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.javaclass。

预期输出（使用 Postman 测试）

Answer 2

@XmlRootElement
public class VisaResponseHeader {

    @XmlElement(name = "id")
    private int id;

    public VisaResponseHeader() {
        id = 3;
    }   
}

Answer 3

尝试在 @RequestMapping 中添加 produces = "application/xml"。你的注释应该是这样的 @RequestMapping(value = "/api", method = RequestMethod.GET,produces = "application/xml").

除此之外，您还应该将 @XmlRootElement(name = "visa") @XmlAccessorType(XmlAccessType.FIELD) 添加到 VisaResponse POJO 并将 @XmlElement 添加到 XML.

中您想要的每个元素

已编辑：

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

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

    @XmlElement
    private int visaNumber;

    public int getVisaNumber() {
        return visaNumber;
    }

    public void setVisaNumber(int visaNumber) {
        this.visaNumber = visaNumber;
    }

}

希望这对您有所帮助。

Answer 4

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



    @XmlRootElement
    public class VisaResponse implements Serializable{

        private int id;

        public VisaResponse() {
            id = 3;
        } 
public getId(){
return id;
}  
public setId(int id) {
this.id = id;
}
    }

将 java 对象转换为 XML REST 响应

Convert java object to XML REST response

java

rest

jaxb

spring-rest