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);
        }
    .......
}

我试图将简单对象转换为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;
    }   
}

但是当我要求休息时，什么也没发生-没有任何反应。 你知道我错了吗？ 应该返回简单内容。

Answer 1

1. 在@RequestMapping中添加产生=“ application / xml” 。 @RequestMapping(value="/api", method=RequestMethod.GET, produces=application/xml")
2. 您需要在bean类（VisaResponseHeader）中添加一些JAXB批注 ，以将其编组为XML。

@XmlRootElement：此批注在顶级类中用于指示XML文档中的根元素。 批注中的name属性是可选的。 如果未指定，则将类名用作文档中的根XML元素。

@XmlAttribute：此批注用于指示根元素的属性。

@XmlElement：此注释用于类的属性，该属性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.java类。

预期输出（使用邮递员测试）

Answer 2

@XmlRootElement
public class VisaResponseHeader {

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

    public VisaResponseHeader() {
        id = 3;
    }   
}

Answer 3

尝试在@RequestMapping内添加produces = "application/xml" 。 您的注释应类似于@RequestMapping(value = "/api", method = RequestMethod.GET,produces = "application/xml") 。

与此同时，您应该将@XmlRootElement(name = "visa") @XmlAccessorType(XmlAccessType.FIELD)到VisaResponse POJO，并将@XmlElement到XML中所需的每个元素。

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;
    }

}

希望这可以帮助。

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;
}
    }