Jaxb:xsi 在根元素中被替换为 ns2

Question

我使用了以下代码片段

 marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,
            Boolean.TRUE);
        marshaller.setSchema(getSchema(xsdSchema));
        marshaller.setProperty("com.sun.xml.internal.bind.namespacePrefixMapper",
            new NamespacePrefixMapper() {
                @Override
                public String getPreferredPrefix(String arg0, String arg1,
                    boolean arg2) {
                    return "tf";
                }
            });
        marshaller.setProperty(Marshaller.JAXB_SCHEMA_LOCATION,
            "http://www.xyz.com/tf " + xsdSchema);
        marshaller.marshal(obj, new StreamResult(xml));

输出 xml：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<tf:abc xmlns:tf="http://www.xyz.com/tf" xmlns:ns2="http://www.w3.org/2001/XMLSchema-instance" ns2:schemaLocation="http://www.xyz.com/tf schema/myxsd.xsd">

如您所见，我得到"ns2"代替了"xsi"。

我需要的是 ns2 位置上的 xsi。

提前谢谢。

Answer 1

命名空间前缀映射器应返回声明的每个命名空间的值：

package mapdemo;
import com.sun.xml.internal.bind.marshaller.NamespacePrefixMapper;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.Marshaller;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
public class JAXBMarshallerExample {
    public static NamespacePrefixMapper val = new NamespacePrefixMapper() {
        private static final String XSI_URI = "http://www.w3.org/2001/XMLSchema-instance";
        private static final String TF_URI = "http://www.xyz.com/tf/whatever.xsd";
        @Override
        public String getPreferredPrefix(String namespaceUri, String suggestion, boolean requirePrefix) {
            if(XSI_URI.equals(namespaceUri)) {
                return "xsi";
            } else if(TF_URI.equals(namespaceUri)) {
                return "tf";
            }
            return suggestion;
        }
        @Override
        public String[] getPreDeclaredNamespaceUris() {
            return new String[] { XSI_URI, TF_URI};
        }
    };
    public static void main(String[] args) throws Exception {
        JAXBContext context = JAXBContext.newInstance(Output.class);
        Marshaller marshaller = context.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        marshaller.setProperty("com.sun.xml.internal.bind.namespacePrefixMapper", val);
        Output output = new Output();
        output.setId("1");
        marshaller.marshal(output, System.out);
    }
    @XmlRootElement(namespace="http://www.xyz.com/tf/whatever.xsd")
    public static class Output {
        String id;
        public String getId() {
            return id;
        }
        @XmlElement
        public void setId(String id) {
            this.id = id;
        }
    }
}

Answer 2

您可以扩展NamespacePrefixMapper的实现来执行此操作，而不是总是从getPreferredPrefix返回tf