防止 Jackson XML 映射器将 wstxns 添加到命名空间

Question

将对象序列化为 XML 并使用 \n @JacksonXmlRootElement(namespace = "http://...")\n指定属性的命名空间时，Jackson 会将 \xc2\xb4wstxns1\xc2\xb4 附加或前置到命名空间。例如，假设我们有这些类：

\n\n

VtexSkuAttributeValues.java

\n\n

@JacksonXmlRootElement(localName = "listStockKeepingUnitName")\npublic class VtexSkuAttributeValues {\n\n    @JacksonXmlProperty(localName = "StockKeepingUnitFieldNameDTO", namespace = "http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts")\n    @JacksonXmlElementWrapper(useWrapping = false)\n    private VtexSkuAttributeValue[] stockKeepingUnitFieldNameDTO;\n\n    public VtexSkuAttributeValue[] getStockKeepingUnitFieldNameDTO() {\n        return stockKeepingUnitFieldNameDTO;\n    }\n\n    public void setValues(VtexSkuAttributeValue[] values) {\n        this.stockKeepingUnitFieldNameDTO = values;\n    }\n}\n

\n\n

VtexSkuAttributeValue.java

\n\n

@JacksonXmlRootElement(localName = "StockKeepingUnitFieldNameDTO", namespace = "http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts")\npublic class VtexSkuAttributeValue {\n\n    private String fieldName;\n    private FieldValues fieldValues;\n    private int idSku;\n\n    public int getIdSku() {\n        return idSku;\n    }\n\n    public String getFieldName() {\n        return fieldName;\n    }\n\n    public FieldValues getFieldValues() {\n        return fieldValues;\n    }\n\n    public void setIdSku(int idSku) {\n        this.idSku = idSku;\n    }\n\n    public void setFieldName(String fieldName) {\n        this.fieldName = fieldName;\n    }\n\n    public void setFieldValues(FieldValues fieldValues) {\n        this.fieldValues = fieldValues;\n    }\n\n    @JacksonXmlRootElement(localName = "fieldValues", namespace = "http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts")\n    public static class FieldValues {\n        @JacksonXmlProperty(namespace = "http://schemas.microsoft.com/2003/10/Serialization/Arrays")\n        @JacksonXmlElementWrapper(useWrapping = false)\n        public String[] string;\n\n        public String[] getString() {\n            return string;\n        }\n\n        public void setValues(String[] values) {\n            this.string = values;\n        }\n    }\n}\n

\n\n

然后我使用XmlMapper来序列化并获取：

\n\n

<listStockKeepingUnitName>\n    <wstxns1:StockKeepingUnitFieldNameDTO xmlns:wstxns1="http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts">\n        <fieldName>talle</fieldName>\n        <fieldValues>\n            <wstxns2:string xmlns:wstxns2="http://schemas.microsoft.com/2003/10/Serialization/Arrays">6184</wstxns2:string>\n        </fieldValues>\n        <idSku>258645</idSku>\n    </wstxns1:StockKeepingUnitFieldNameDTO>\n    <wstxns3:StockKeepingUnitFieldNameDTO xmlns:wstxns3="http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts">\n        <fieldName>color</fieldName>\n        <fieldValues>\n            <wstxns4:string xmlns:wstxns4="http://schemas.microsoft.com/2003/10/Serialization/Arrays">6244</wstxns4:string>\n        </fieldValues>\n        <idSku>258645</idSku>\n    </wstxns3:StockKeepingUnitFieldNameDTO>\n</listStockKeepingUnitName>\n

\n\n

尽管这是有效的 XML，但我正在使用的 Web 服务不接受它。我对其进行了调试，这是由于wstxnsJackson 由于某种原因添加的标签中的属性所致。\n有没有办法阻止 Jackson 将其添加到标签中。我能想到的唯一解决方法是对生成的 XML 执行 string.replaceAll，但这显然并不理想。

\n

Answer 1

编写XML Jackson使用javax.xml.stream.XMLStreamWriter. 您可以配置该类的实例并为命名空间定义自己的前缀，并根据需要设置默认前缀。为此，我们需要扩展com.fasterxml.jackson.dataformat.xml.XmlFactory类并重写创建实例的方法XMLStreamWriter。示例实现如下所示：

class NamespaceXmlFactory extends XmlFactory {

    private final String defaultNamespace;
    private final Map<String, String> prefix2Namespace;

    public NamespaceXmlFactory(String defaultNamespace, Map<String, String> prefix2Namespace) {
        this.defaultNamespace = Objects.requireNonNull(defaultNamespace);
        this.prefix2Namespace = Objects.requireNonNull(prefix2Namespace);
    }

    @Override
    protected XMLStreamWriter _createXmlWriter(IOContext ctxt, Writer w) throws IOException {
        XMLStreamWriter writer = super._createXmlWriter(ctxt, w);
        try {
            writer.setDefaultNamespace(defaultNamespace);
            for (Map.Entry<String, String> e : prefix2Namespace.entrySet()) {
                writer.setPrefix(e.getKey(), e.getValue());
            }
        } catch (XMLStreamException e) {
            StaxUtil.throwAsGenerationException(e, null);
        }
        return writer;
    }
}

您可以按如下方式使用它：

import com.fasterxml.jackson.core.io.IOContext;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.dataformat.xml.XmlFactory;
import com.fasterxml.jackson.dataformat.xml.XmlMapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;
import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
import com.fasterxml.jackson.dataformat.xml.util.StaxUtil;

import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.Collections;
import java.util.Map;
import java.util.Objects;

public class XmlMapperApp {

    public static void main(String[] args) throws Exception {
        String defaultNamespace = "http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts";
        Map<String, String> otherNamespaces = Collections.singletonMap("a", "http://schemas.microsoft.com/2003/10/Serialization/Arrays");

        XmlMapper xmlMapper = new XmlMapper(new NamespaceXmlFactory(defaultNamespace, otherNamespaces));
        xmlMapper.enable(SerializationFeature.INDENT_OUTPUT);

        System.out.println(xmlMapper.writeValueAsString(new VtexSkuAttributeValues()));
    }
}

在VtexSkuAttributeValues课堂上你可以声明：

public static final String DEF_NMS = "http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts";

并将其用于应用作默认命名空间的每个类和字段。例如：

@JacksonXmlProperty(localName = "StockKeepingUnitFieldNameDTO", namespace = DEF_NMS)

对于您不想更改名称的属性，可以使用：

@JacksonXmlProperty(namespace = VtexSkuAttributeValues.DEF_NMS)

上面的代码打印一些随机数据：

<listStockKeepingUnitName>
  <StockKeepingUnitFieldNameDTO xmlns="http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts">
    <fieldName>Name1</fieldName>
    <fieldValues>
      <a:string xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">6184</a:string>
    </fieldValues>
    <idSku>123</idSku>
  </StockKeepingUnitFieldNameDTO>
  <StockKeepingUnitFieldNameDTO xmlns="http://schemas.datacontract.org/2004/07/Vtex.Commerce.WebApps.AdminWcfService.Contracts">
    <fieldName>Name1</fieldName>
    <fieldValues>
      <a:string xmlns:a="http://schemas.microsoft.com/2003/10/Serialization/Arrays">6184</a:string>
    </fieldValues>
    <idSku>123</idSku>
  </StockKeepingUnitFieldNameDTO>
</listStockKeepingUnitName>

如果这不是您想要的，您可以使用该代码并尝试其他可用于配置此实例的方法。

使用Jackson版本来创建此示例。2.9.9