指定名称空间JAXB的前缀

Question

面临使用JAXB解组的问题。我需要使用多个名称空间。Java类是为第三方提供的XSD生成的。因此，我不想在Java类中的XMLRootElement指定名称空间，也不想手动更改多个类。

编组逻辑如下：

private <R extends BasicResponseType, T extends BasicRequestType> R doPost(T request, String requestname) throws Exception {
    if (jaxbContext == null)
        jaxbContext = JAXBContext.newInstance(TokenRequest.class, TokenResponse.class,
                BasicResponseType.class, GeneralErrorResponse.class);
    Marshaller marshaller = jaxbContext.createMarshaller();
    marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
    marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
    Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
    logXML(marshaller, request);
    // POST to baseURL/requestname and show response
    HttpURLConnection conn = openConnection("/" + requestname);

    OutputStream os = conn.getOutputStream();
    marshaller.marshal(request, os);
    os.flush();
    // Normaler Output oder Error liefern, je nach HTTP Response
    InputStream is = null;
    boolean ok = true;
    if (conn.getResponseCode() != HttpURLConnection.HTTP_OK) {
        is = conn.getErrorStream();
        ok = false;
    } else {
        is = conn.getInputStream();
    }
    R response = (R) unmarshaller.unmarshal(new StreamSource(is));
    is.close();
    conn.disconnect();
    logXML(marshaller, response);
    if (ok) {
        return response;
    } else {
        throw new Exception(getMessages((GeneralErrorResponse) response));
    }
}

xmlelement类TokenRequest.java

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "")
@XmlRootElement(name = "TokenRequest")
public class TokenRequest
extends BasicInRequestType{ }

BasicInRequestType.java

package exp._3_0.api;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlSeeAlso;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "BasicInRequestType", propOrder = {
"software"
})
@XmlSeeAlso({
TokenRequest.class    
})
public class BasicInRequestType
extends BasicRequestType {

@XmlElement(required = true)
protected SoftwareType software;

/**
 * Gets the value of the software property.
 * 
 * @return
 *     possible object is
 *     {@link SoftwareType }
 *     
 */
public SoftwareType getSoftware() {
    return software;
}

/**
 * Sets the value of the software property.
 * 
 * @param value
 *     allowed object is
 *     {@link SoftwareType }
 *     
 */
public void setSoftware(SoftwareType value) {
    this.software = value;
}}

package exp._3_0.api;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlSeeAlso;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
propOrder = {
"header",
"user"
})
@XmlSeeAlso({
    BasicInRequestType.class
})
public class BasicRequestType {

@XmlElement(required = true)
protected BasicHeaderType header;
@XmlElement(required = true)
protected UserHeaderType user;
@XmlType(name = "BasicRequestType", namespace = "http://foo/1.0/common", 
/**
 * Gets the value of the header property.
 * 
 * @return
 *     possible object is
 *     {@link BasicHeaderType }
 *     
 */
public BasicHeaderType getHeader() {
    return header;
}

/**
 * Sets the value of the header property.
 * 
 * @param value
 *     allowed object is
 *     {@link BasicHeaderType }
 *     
 */
public void setHeader(BasicHeaderType value) {
    this.header = value;
}

/**
 * Gets the value of the user property.
 * 
 * @return
 *     possible object is
 *     {@link UserHeaderType }
 *     
 */
public UserHeaderType getUser() {
    return user;
}

/**
 * Sets the value of the user property.
 * 
 * @param value
 *     allowed object is
 *     {@link UserHeaderType }
 *     
 */
public void setUser(UserHeaderType value) {
    this.user = value;
}}

<TokenRequest xmlns:common="http://foo/1.0/common" xmlns:ns4="http://foo/3.0/api" xmlns:base="http://foo/3.0/base">
    <common:header>
        <common:requestId></common:requestId>
        <common:timestamp></common:timestamp>
    </common:header>
    <common:user>
        <common:login></common:login>
        <common:passwordHash></common:passwordHash>
    </common:user>
    <software>
        <softwareId></softwareId>
        <softwareName></softwareName>
    </software>
</TokenRequest>

我在package-info.java中指定了前缀

@javax.xml.bind.annotation.XmlSchema(elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED, xmlns = {
@javax.xml.bind.annotation.XmlNs(namespaceURI = "http://foo/3.0/api", prefix = ""),
@javax.xml.bind.annotation.XmlNs(namespaceURI = "http://foo/3.0/base", prefix = "base"), 
@javax.xml.bind.annotation.XmlNs(namespaceURI = "http://foo/1.0/common", prefix = "common") })
package exp._3_0.api;

TokenRequest元素实际上引用了名称空间=“http://foo/3.0/API”。在xml输出中，TokenRequest没有正确的any前缀，但是xmlns被设置为ns4，这导致了下面的错误。

请求正文包含行[1]和列[182]错误：[意外的元素（URI：“”，本地：“TokenRequest”）。需要的元素为<{http：//foo/3.0/API}TokenRequest>]

即使在package-info中为namespace“http：//foo/3.0/api”指定了前缀=“”之后，在输出中它仍然附加为NS4。请帮助如何修复删除NS4。

Answer 1

如注释中所述，@xmlschema缺少namespace属性，因此，除非显式限定，否则所有@xmlrootelement和@xmltype都被认为没有命名空间。您的java-package.info应该如下所示：

@XmlSchema(elementFormDefault = XmlNsForm.QUALIFIED, namespace = "http://foo/3.0/api", xmlns = {
      @XmlNs(namespaceURI = "http://foo/3.0/api", prefix = ""),
      @XmlNs(namespaceURI = "http://foo/3.0/base", prefix = "base"),
      @XmlNs(namespaceURI = "http://foo/1.0/common", prefix = "common")})
package exp._3_0.api;

import javax.xml.bind.annotation.XmlNs;
import javax.xml.bind.annotation.XmlNsForm;
import javax.xml.bind.annotation.XmlSchema;

@xmlns注释不指定Java包中使用的默认名称空间。它们只向JAXB实现提供一个建议，说明要为那些名称空间分配什么前缀。在您的示例中，标记 、 和 不属于任何名称空间，因此，JAXB为这些元素使用了一个空前缀，并且必须为http://foo/3.0/api名称空间中的元素使用另一个前缀(ns4)（没有任何名称空间）。