java - 将 XML 中的元素分成单独的文件

Question

我有一个包含许多嵌套主题元素的 XML 文件。例如:

<?xml version="1.0" encoding="UTF-8"?>
<topic id="topic-1">
    <title>ADBT</title>

    <para>The program executes a database request by using the ADBT
        library. The ADBT library prepares
        the request and calls an ODBC driver
        or a native API.  
    </para>

    <topic id="topic_wom_eqy_ev">
        <title>Establishing a connection</title>
        <para>
            In order to use a database with ADBT, the first step to be taken
            is
            to establish a
            connection.
        </para>

    </topic>
    <topic id="topic_dsw_gqy_ev">
        <title>Querying a database</title>
        <para>Querying a database involves a number of stages.</para>
        <topic id="topic_ljf_isy_ev">
            <title>Stage one: create a query</title>
            <para> A new query (ADBT_Select object) can only be created starting
                from a previously
                established connection. A query is created using
                the CreateSelect method in two
                different
                ways:
            </para>
        </topic>
    </topic>

</topic>

我希望将每个主题分成一个新的 XML 文件，文件名与标题相同。如果一个主题包含另一个主题，则该主题将是一个单独的文件，并且父主题将是一个单独的文件，其内容不包括子主题。例如，在本例中，将有四个文件作为输出，内容如下:

第 1 号:

<topic id="topic-1">
        <title>ADBT</title>

        <para>The program executes a database request by using the ADBT
            library. The ADBT library prepares
            the request and calls an ODBC driver or a native API.  
        </para>
    </topic>

数字 2:

<topic id="topic_wom_eqy_ev">
        <title>Establishing a connection</title>
        <para>
            In order to use a database with ADBT, the first step to be taken is
            to establish a
            connection. 
        </para>     

    </topic>

第三号:

<topic id="topic_dsw_gqy_ev">
        <title>Querying a database</title>
        <para>Querying a database involves a number of stages.</para>
</topic>

第四号:

<topic id="topic_ljf_isy_ev">
            <title>Stage one: create a query</title>
            <para> A new query (ADBT_Select object) can only be created starting
                from a previously
                established connection. A query is created using the CreateSelect method in two
                different
                ways:
            </para>
            </topic>

我编写了一些函数，但我无法弄清楚如何分离多级嵌套主题。

Answer 1

基本上，您想要做的是:

• 使用您选择的 XML 阅读器读取 XML
• 获取所有<topic>递归地遍历文档中的元素
• 对于每个 <topic>元素，创建该元素的副本(可能为每个元素创建一个新文档，其根为 <topic> 元素)，复制原始元素中的所有子元素，但 tagName = topic 的子元素除外。这保证了递归调用不会产生重叠元素
• 对于每个创建的 Document s，使用您选择的 XML 编写器将其序列化为文件

因此，对于示意性代码:

Document document = readXMLDocument(...);
List<Element> topicElements = readTopicElementsRecursively(document);
List<Document> splitTopicDocuments = new ArrayList<>();
for (Element el : topicElements) {
    Document doc = copyElementWithoutTopicChildren(el);
    splitTopicDocuments.add(doc);
}
writeTopicDocuments(splitTopicDocuments);