Question

我有从架构创建的JAXB对象。在编组时，xml元素将使用ns2进行注释。我已经尝试过网络上存在的所有选项，但是这些选项都不起作用。我无法修改我的架构或更改package-info.java。请帮忙

Answer 1

经过大量的研究和修补，我终于设法解决了这个问题。请接受我的道歉，因为没有发布原始参考文献的链接 - 有许多我没有做笔记 - 但是this一个肯定是有用的。

我的解决方案使用过滤XMLStreamWriter，它应用空名称空间上下文。

public class NoNamesWriter extends DelegatingXMLStreamWriter {

  private static final NamespaceContext emptyNamespaceContext = new NamespaceContext() {

    @Override
    public String getNamespaceURI(String prefix) {
      return "";
    }

    @Override
    public String getPrefix(String namespaceURI) {
      return "";
    }

    @Override
    public Iterator getPrefixes(String namespaceURI) {
      return null;
    }

  };

  public static XMLStreamWriter filter(Writer writer) throws XMLStreamException {
    return new NoNamesWriter(XMLOutputFactory.newInstance().createXMLStreamWriter(writer));
  }

  public NoNamesWriter(XMLStreamWriter writer) {
    super(writer);
  }

  @Override
  public NamespaceContext getNamespaceContext() {
    return emptyNamespaceContext;
  }

}

您可以找到DelegatingXMLStreamWriter here。

然后，您可以使用以下方法过滤编组xml

  // Filter the output to remove namespaces.
  m.marshal(it, NoNamesWriter.filter(writer));

我确信有更有效的机制，但我知道这个机制有效。

Answer 2

对我来说，只更改package-info.java类就像魅力一样，就像zatziky所说：

package-info.java

 @javax.xml.bind.annotation.XmlSchema
 (namespace = "http://example.com",
 xmlns = {@XmlNs(prefix = "", namespaceURI = "http://example.com")},
 elementFormDefault = javax.xml.bind.annotation.XmlNsForm.QUALIFIED)

package my.package;
import javax.xml.bind.annotation.XmlNs;

Answer 3

您可以只将命名空间写入一次。您将需要XMLStreamWriter的代理类和package-info.java。然后你会在你的代码中做到：

StringWriter stringWriter = new StringWriter();
XMLStreamWriter writer = new Wrapper((XMLStreamWriter) XMLOutputFactory
                                                               .newInstance().createXMLStreamWriter(stringWriter));
JAXBContext jaxbContext = JAXBContext.newInstance(Collection.class);
Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
jaxbMarshaller.marshal(books, writer);
System.out.println(stringWriter.toString());

代理类（重要的方法是“writeNamespace”）：

            class WrapperXMLStreamWriter implements XMLStreamWriter {

                   private final XMLStreamWriter writer;

                   public WrapperXMLStreamWriter(XMLStreamWriter writer) {
                       this.writer = writer;
                   }

                     //keeps track of what namespaces were used so that not to 
                     //write them more than once
                   private List<String> namespaces = new ArrayList<String>();

                   public void init(){
                       namespaces.clear();
                   }

                   public void writeStartElement(String localName) throws XMLStreamException {
                       init();
                       writer.writeStartElement(localName);

                   }

                   public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
                       init();
                       writer.writeStartElement(namespaceURI, localName);
                   }

                   public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
                       init();
                       writer.writeStartElement(prefix, localName, namespaceURI);
                   }

                   public void writeNamespace(String prefix, String namespaceURI) throws XMLStreamException {
                       if(namespaces.contains(namespaceURI)){ 
                           return;
                       }
                       namespaces.add(namespaceURI);
                       writer.writeNamespace(prefix, namespaceURI);
                   }

    // .. other delegation method, always the same pattern: writer.method() ...

}

package-info.java：

@XmlSchema(elementFormDefault=XmlNsForm.QUALIFIED, attributeFormDefault=XmlNsForm.UNQUALIFIED ,
        xmlns = { 
        @XmlNs(namespaceURI = "http://www.w3.org/2001/XMLSchema-instance", prefix = "xsi")})
package your.package;

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

Answer 4

您可以使用NamespacePrefixMapper扩展名来控制用例的名称空间前缀。 JAXB参考实现和EclipseLink JAXB（MOXy）都支持相同的扩展。

http://wiki.eclipse.org/EclipseLink/Release/2.4.0/JAXB_RI_Extensions/Namespace_Prefix_Mapper

Answer 5

每个解决方案都需要复杂的覆盖或注释，这似乎不适用于最新版本。我使用了一种更简单的方法，只需替换烦人的命名空间即可。我希望 Google & Co 使用 JSON 并摆脱 XML。

kml.marshal(file);

String kmlContent = FileUtils.readFileToString(file, "UTF-8");
kmlContent = kmlContent.replaceAll("ns2:","").replace("<kml xmlns:ns2=\"http://www.opengis.net/kml/2.2\" xmlns:ns3=\"http://www.w3.org/2005/Atom\" xmlns:ns4=\"urn:oasis:names:tc:ciq:xsdschema:xAL:2.0\" xmlns:ns5=\"http://www.google.com/kml/ext/2.2\">", "<kml>");
FileUtils.write(file, kmlContent, "UTF-8");

Answer 6

我通过设置属性获得了工作结果：

marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION, "");

在JAXB编组时删除名称空间前缀

6 个答案: