Is there a way to seek a specific location in an xml by knowing the index relative to the text nodes in java?

I have a xml document. I know the index where i need to insert the new node. The index that i have is the position considering only the text nodes and ignoring the element tags. Is there a java api to seek the index in a xml knowing the position relative to the text nod开发者_如何学Pythones alone and insert a new node in that position?

---

Here is an XSLT 2.0 stylesheet that takes two parameters, the index at which you want to insert (using XSLT/XPath indexing scheme where the index starts with one, not with zero), and the node(s) to insert:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xsd"
  version="2.0">

  <!-- XPath/XSLT index starts with 1 -->
  <xsl:param name="index" as="xsd:integer" select="11"/>
  <xsl:param name="new" as="node()+"><e/></xsl:param>

  <xsl:variable name="text-to-split" as="text()?"
     select="descendant::text()[sum((preceding::text(), .)/string-length(.)) ge $index][1]"/>

  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="text()[. is $text-to-split]">
    <xsl:variable name="split-index" as="xsd:integer"
      select="$index - sum(preceding::text()/string-length(.))"/>
    <xsl:value-of select="substring(., 1, $split-index - 1)"/>
    <xsl:copy-of select="$new"/>
    <xsl:value-of select="substring(., $split-index)"/>
  </xsl:template>

</xsl:stylesheet>

You can use Saxon 9 to run XSLT 2.0 stylesheets with Java. [edit] Here is an attempt to solve this with XSLT 1.0:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="1.0">

  <!-- XPath/XSLT index starts with 1 -->
  <xsl:param name="index" select="11"/>
  <xsl:param name="new"><e/></xsl:param>

  <xsl:template name="find-text-to-split">
    <xsl:param name="text-nodes"/>
    <xsl:variable name="sum">
      <xsl:call-template name="make-sum">
        <xsl:with-param name="nodes" select="$text-nodes[1]/preceding::text() | $text-nodes[1]"/>
      </xsl:call-template>
    </xsl:variable>
    <xsl:choose>
      <xsl:when test="$sum &gt;= $index">
        <xsl:value-of select="generate-id($text-nodes[1])"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="find-text-to-split">
          <xsl:with-param name="text-nodes" select="$text-nodes[position() &gt; 1]"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <xsl:template name="make-sum">
    <xsl:param name="nodes"/>
    <xsl:param name="length" select="0"/>
    <xsl:choose>
      <xsl:when test="not($nodes)">
        <xsl:value-of select="$length"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="make-sum">
          <xsl:with-param name="nodes" select="$nodes[position() &gt; 1]"/>
          <xsl:with-param name="length" select="$length + string-length($nodes[1])"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <xsl:variable name="text-to-split-id">
    <xsl:call-template name="find-text-to-split">
      <xsl:with-param name="text-nodes" select="descendant::text()"/>
    </xsl:call-template>
  </xsl:variable>

  <xsl:template match="*">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="@* | comment() | processing-instruction()">
    <xsl:copy/>
  </xsl:template>

  <xsl:template match="text()">
    <xsl:choose>
      <xsl:when test="generate-id() = $text-to-split-id">
        <xsl:variable name="sum">
          <xsl:call-template name="make-sum">
            <xsl:with-param name="nodes" select="preceding::text()"/>
          </xsl:call-template>
        </xsl:variable>
        <xsl:variable name="split-index"
          select="$index - $sum"/>
        <xsl:value-of select="substring(., 1, $split-index - 1)"/>
        <xsl:copy-of select="$new"/>
        <xsl:value-of select="substring(., $split-index)"/>
      </xsl:when>
      <xsl:otherwise>
        <xsl:copy/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

</xsl:stylesheet>

Note that the XSLT 1.0 solution is not quite complete, it might recurse to a stack overflow if the index passed in is greater than any existing text index in the document.

---

The following XSLT 2.0 stylesheet is an attempt to extend the solution in the original XSLT 2.0 stylesheet to receive a list of index positions and nodes to be inserted with one transformation:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="xsd"
  version="2.0">

  <xsl:param name="insert-file" as="xsd:string" select="'insert-data.xml'"/>

  <xsl:variable name="main-root" as="document-node()" select="/"/>

  <xsl:variable name="insert-data" as="element(data)*">
    <xsl:for-each-group select="doc($insert-file)/insert-data/data" group-by="xsd:integer(@index)">
      <xsl:sort select="current-grouping-key()"/>
      <data index="{current-grouping-key()}" text-id="{generate-id($main-root/descendant::text()[sum((preceding::text(), .)/string-length(.)) ge current-grouping-key()][1])}">
        <xsl:copy-of select="current-group()/node()"/>
      </data>
    </xsl:for-each-group>
  </xsl:variable>

  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@*, node()"/>
    </xsl:copy>
  </xsl:template>

  <xsl:template match="text()[generate-id() = $insert-data/@text-id]">
    <xsl:variable name="preceding-text" as="xsd:integer" select="sum(preceding::text()/string-length(.))"/>
    <xsl:variable name="this" as="text()" select="."/>
    <xsl:variable name="insert-here" as="element(data)+">
      <xsl:for-each select="$insert-data[@text-id = generate-id(current())]">
        <data split-index="{@index - $preceding-text}">
          <xsl:copy-of select="node()"/>
        </data>
      </xsl:for-each>
    </xsl:variable>

    <xsl:for-each select="$insert-here">
      <xsl:variable name="pos" as="xsd:integer" select="position()"/>
      <xsl:value-of select="substring(
        $this, 
        if ($pos eq 1) then 1 else xsd:integer($insert-here[$pos - 1]/@split-index), 
        if ($pos ne 1) then xsd:integer(@split-index) - xsd:integer($insert-here[$pos - 1]/@split-index) else xsd:integer(@split-index) - 1)"/>
      <xsl:copy-of select="node()"/>
    </xsl:for-each>

    <xsl:value-of select="substring($this, $insert-here[last()]/@split-index)"/>  
  </xsl:template>

</xsl:stylesheet>

This stylesheet expects a file insert-data.xml to contain the data in the following format:

<insert-data>
  <data index="2"><e/></data>
  <data index="4"><f/></data>
  <data index="6"><g/></data>
  <data index="6"><h/></data>
  <data index="18"><i/></data>
</insert-data>

So each 'data' element contains the nodes to be inserted at the position given by the 'index' attribute.

---

As such there is no direct API in Java to achieve this. But there is XPATH library and DOM parsing techniques where by using little programing you can achieve this easily