Java中的XML：打印每个节点一次（而不是多次）

Question

我有以下xml结构（在我的XML文件中有更多的节点，但我认为这足以进行演示）：

<log>
    <published>2014-03-28T15:28:36.646Z</published>
    <actor>
        <objectType>person</objectType>
        <id>e1b8948f-321e-78ca-d883-80500aae71b5</id>
        <displayName>anonymized</displayName>
    </actor>
    <verb>update</verb>
    <object>
        <objectType>concept</objectType>
        <id>a1ad6ace-c722-ffa9-f58e-b4169acdb4e3</id>
        <content>time</content>
    </object>
</log>

以下方法打印所有节点：

public static void parseRecursive(Node node, Node parent) {

    NodeList childs = node.getChildNodes();
    if (parent != null) {
        toXes.createString(parent.getNodeName(), "");
    }
    for (int i = 0; i < childs.getLength(); i++) {
        if (childs.getLength() > 1) {
            parseRecursive(childs.item(i), node);
        } else {
            toXes.createNestedString(node.getNodeName(), childs.item(i).getNodeValue(), "string");
            System.out.println("PARENT: " + parent.getNodeName());

            System.out.println("CHILD-KEY: " + node.getNodeName());

            System.out.println("CHILD-VALUE: " + childs.item(i).getNodeValue());
            System.out.println("--------------------------------------------");
        }
    }
}

输出看起来像这样（再次缩短，它是我的输出＆＃34; createString / createNestedString＆＃34; -methods）：

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<log xes.features="" xes.version="2.0">
  <trace>
    <event>
      <string key="log" value=""/>
      <string key="log" value="">
        <string key="published" value="2014-03-28T15:28:36.646Z"/>
      </string>
      <string key="log" value=""/>
      <string key="log" value=""/>
      <string key="actor" value=""/>
      <string key="actor" value="">
        <string key="objectType" value="person"/>
      </string>
      <string key="actor" value=""/>
      <string key="actor" value="">
        <string key="id" value="e1b8948f-321e-78ca-d883-80500aae71b5"/>
      </string>
      <string key="actor" value=""/>
      <string key="actor" value="">
        <string key="displayName" value="anonymized"/>
      </string>
      <string key="actor" value=""/>
      ...

我的问题是我不知道为什么有些节点被多次打印。我希望例如＆＃34; log＆＃34;和＆＃34;演员＆＃34;只出现一次 - 它们的子节点也被附加一次（实际上它们只会在输出中看到一次附加...但父节点经常打印）。我怎么能做到这一点？

CreateString只是将一个String-Node附加到log元素，而createNestedString只是将一个子节点附加到父节点元素。

修改

//Appends the <string>-element to the <log>-element.
public static void createString(String key, String value) {
    stringElement = doc.createElement("string");
    eventElement.appendChild(stringElement);

    // attributes of "string"-element in .xes - key
    attr = doc.createAttribute("key");
    attr.setValue(key);
    stringElement.setAttributeNode(attr);

    // attributes of "string"-element in .xes - value
    attr = doc.createAttribute("value");
    attr.setValue(value);
    stringElement.setAttributeNode(attr);
}

//Asks whether the attribute is nested.
//Valid params: log, event, ...
public static void createNestedString(String key, String value, String nested) {
    Element stringElement2 = doc.createElement("string");
    if (nested.equals("log")) {
        logElement.appendChild(stringElement2);
    } else if (nested.equals("global")) {
        globalElement.appendChild(stringElement2);
    } else if (nested.equals("trace")) {
        traceElement.appendChild(stringElement2);
    } else if (nested.equals("event")) {
        eventElement.appendChild(stringElement2);
    } else if (nested.equals("int")) {
        intElement.appendChild(stringElement2);
    } else if (nested.equals("date")) {
        dateElement.appendChild(stringElement2);
    } else if (nested.equals("string")) {
        stringElement.appendChild(stringElement2);
    } else if (nested.equals("float")) {
        floatElement.appendChild(stringElement2);
    } else if (nested.equals("boolean")) {
        booleanElement.appendChild(stringElement2);
    } else if (nested.equals("id")) {
        idElement.appendChild(stringElement2);
    } else if (nested.equals("list")) {
        listElement.appendChild(stringElement2);
    } else if (nested.equals("container")) {
        containerElement.appendChild(stringElement2);
    } else {
        System.err.println("ERROR: Could not append nested <string> to another element.");
    }

    // attributes of "string"-element in .xes - key
    attr = doc.createAttribute("key");
    attr.setValue(key);
    stringElement2.setAttributeNode(attr);

    // attributes of "string"-element in .xes - value
    attr = doc.createAttribute("value");
    attr.setValue(value);
    stringElement2.setAttributeNode(attr);
}