Spring Jaxb2RootElementHttpMessageConverter无法使用jaxb注释工作

Question

我已经设置了Spring来使用Jaxb2RootElementHttpMessageConverter作为消息转换器将对象转换为XML。在我的REST服务中，当响应生成时，它不遵循我在模型类上提供的JAXB注释。
:

BaseResponse：

@XmlRootElement(name="response")
@XmlSeeAlso({AddMemberResponse.class,UpdateMemberResponse.class})
public abstract class BaseResponse {


    private int status;
    private String message;
    private String confirmationCode;

    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
    public int getStatus() {
        return status;
    }
    public void setStatus(int httpInternalError) {
        this.status = httpInternalError;
    }
    public String getConfirmationCode() {
        return confirmationCode;
    }
    public void setConfirmationCode(String confirmationCode) {
        this.confirmationCode = confirmationCode;
    }
}

AddMemberResponse:

@XmlRootElement(name = "response")
@XmlAccessorType(XmlAccessType.FIELD)
public class AddMemberResponse extends BaseResponse {

    private Member member;

    public AddMemberResponse() {
        super();
    }

    public Member getMember() {
        return member;
    }

    public void setMember(Member member) {
        this.member = member;
    }
}

我的代码中有一个需要将XML保存到数据库的地方，因此我需要手动将其转换为字符串以便稍后保存，为此我使用JaxbMarshaller类，这个方法很有效：

/**
 * Converts object to xml using jaxb marshaller
 */
private String objectToXML(Object graph) throws IOException {

    String finalstring = null;
    try {

        Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
        marshaller.setPackagesToScan("com.company.ws");
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("jaxb.formatted.output", true);
        marshaller.setMarshallerProperties(map);

        // create a StringWriter for the output
        StringWriter outWriter = new StringWriter();
        StreamResult result = new StreamResult(outWriter);
        marshaller.marshal(graph, result);

        StringBuffer sb = outWriter.getBuffer();
        finalstring = sb.toString();
        log.debug(finalstring);

    } catch(Exception e) {
        e.printStackTrace();
    }
    return finalstring;
}

它使用jaxbmarshaller将此内容存储在数据库中，方法如下：

<response>
    <status>500</status>
</response> 

但是它在POSTMAN中返回这个响应：

<AddMemberResponse>
    <status>500</status>
    <message/>
    <confirmationCode>UVHRWLHB6UMQ</confirmationCode>
    <member/>
</AddMemberResponse>

这里的500是由于无法连接外部服务获取数据而导致的，所以它并不相关，应该按照描述返回最初的方式。

app-servlet.xml已配置消息转换器：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <!-- Enables the Spring4 @Controller  -->
    <mvc:annotation-driven />

    <!-- To  convert JSON to Object and vice versa -->
    <bean id="jsonMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
    </bean> 

     <!-- To  convert XML to Object and vice versa -->
    <bean id="xmlMessageConverter" class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter">
    </bean> 


<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
    <property name="messageConverters">
        <list>
            <ref bean="jsonMessageConverter"/>
            <ref bean="xmlMessageConverter"/>
        </list>
    </property> 
</bean>     
    <!-- Dozer configuration -->
    <bean id="beanMapper" class="org.dozer.DozerBeanMapper">
      <property name="mappingFiles">
        <list>
          <value>dozerMapping.xml</value>
        </list>
      </property>
    </bean>


    <context:component-scan base-package="com.company" />

</beans>

更新1：

as "application/xml" using [org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter@3f767117]

在日志中显示，因此在将其编组为响应时未使用正确的转换器。

- ephemeralCoder

Answer 1

我需要从类路径中删除一个Jackson依赖项：

<dependency>
    <groupId>com.fasterxml.jackson.jaxrs</groupId>
    <artifactId>jackson-jaxrs-xml-provider</artifactId>
    <version>2.4.3</version>
</dependency>

如果classpath中有MappingJackson2XmlHttpMessageConverter@3f767117，则它优先于jaxb转换器，因此映射将由该转换器而不是我的jaxb转换器执行。

- ephemeralCoder

Answer 2

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {

    converters.add(new MappingJackson2HttpMessageConverter());
    converters.add(new Jaxb2RootElementHttpMessageConverter());
}

//在pom中添加以下内容

com.fasterxml.jackson.core jackson-databind 2.13.5

com.fasterxml.jackson.jaxrs jackson-jaxrs-json-provider 2.14.0

- kiarash shamaii