如何使用MOXy将Map编组为{key:value,key:value,...}

时间:2013-09-13 06:53:11

标签: java json jaxb moxy

使用Eclipselink MOXy,我有以下课程:

@XmlAccessorType(XmlAccessType.PUBLIC_MEMBER)
@XmlType(name = "")
public class MyObject {
  private Map<String, String> meta;

  @XmlPath(".")
  @XmlJavaTypeAdapter(MetaMapAdapter.class)
  public Map<String, String> getMeta() {
    return meta;
  }

  public setMeta(Map<String, String> m) {
    meta = m;
  }
}

我的AdaptedMap看起来像这样(归功于JAXB: how to marshall map into <key>value</key>):

import javax.xml.bind.annotation.XmlAnyElement;

public class AdaptedMap {
    private Object value;
    public AdaptedMap() {}
    @XmlAnyElement
    public Object getValue() { return value; }
    public void setValue(final Object value) { this.value = value; }
}

MapAdapter看起来像这样(归功于JAXB: how to marshall map into <key>value</key>):

import java.util.*;
import javax.xml.bind.annotation.adapters.XmlAdapter;
import javax.xml.parsers.*;
import org.eclipse.persistence.oxm.XMLRoot;
import org.w3c.dom.*;

public class MetaMapAdapter extends XmlAdapter<AdaptedMap, Map<String, String>> {
    public MapAdapter() {}

    @Override public AdaptedMap marshal(final Map<String, String> map) throws Exception {
        if (map == null) { return null; }

        final DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        final DocumentBuilder db = dbf.newDocumentBuilder();
        final Document document = db.newDocument();
        final Element rootElement = document.createElement(getTagName());
        document.appendChild(rootElement);

        for (final Entry<String, String> entry : map.entrySet()) {
            final Element mapElement = document.createElement(entry.getKey());
            mapElement.setTextContent(entry.getValue());
            rootElement.appendChild(mapElement);
        }

        final AdaptedMap adaptedMap = new AdaptedMap();
        adaptedMap.setValue(document);

        return adaptedMap;
    }

    @Override public Map<String, String> unmarshal(final AdaptedMap adaptedMap) {
        if (adaptedMap == null) { return null; }

        final Map<String, String> map = new HashMap<String, String>();
        final Element rootElement = (Element) adaptedMap.getValue();
        final NodeList childNodes = rootElement.getChildNodes();

        for (int x = 0, size = childNodes.getLength(); x < size; x++) {
            final Node childNode = childNodes.item(x);

            if (childNode.getNodeType() == Node.ELEMENT_NODE) {
                map.put(childNode.getLocalName(), childNode.getTextContent());
            }
        }

        return map;
    }
}

通过使用Eclipselink MOXy,我可以在XmlPath的帮助下获得此JSON:

{
  "meta": {
    "akey":"avalue",
    "bkey":"bvalue"
  }
}

不幸的是,由于使用XmlPath来折叠外元元素,我无法反向解组MyObject。

另一方面,我也无法在Eclipselink 2.6中使用新的XmlVariableNode,因为我只允许使用API​​的稳定版本:(

任何人都知道如何解决这个问题?

1 个答案:

答案 0 :(得分:3)

  

另一方面,我也无法使用新的XmlVariableNode   Eclipselink 2.6因为我只允许使用API​​的稳定版本   :(

@XmlVariableNode也包含在EclipseLink 2.5.1中,现已发布:

此注释非常适合映射您的用例: