java - Append an element in a XML using DOM keeping the format -

i have xml this

<?xml version="1.0" encoding="utf-8" standalone="no"?> <empleado>   <consultortecnico>     <nombre>pablo</nombre>     <legajo antiguedad="4 meses">7778</legajo>   </consultortecnico>   <cnc>     <nombre>brian</nombre>     <legajo antiguedad="1 año, 7 meses">2134</legajo>   <sueldo>4268.0</sueldo>   </cnc> </empleado> 

what want read xml , append "sueldo" @ same level "nombre" , "legajo" in element "cnc". "sueldo" must "legajo" x 2

the code have appends "sueldo" can see in xml above not indent should, im using propierties indent (this xml created same way, using dom)

public class main {     public static void main(string[] args)     {         try         {           file xml = new file("c:\\empleado.xml");           if (xml.exists() == true)           {             documentbuilderfactory dbf = documentbuilderfactory.newinstance();             documentbuilder db = dbf.newdocumentbuilder();             document doc = db.parse(xml);              string legajo = doc.getelementsbytagname("legajo").item(1).getfirstchild().getnodevalue();          element sueldo = doc.createelement("sueldo");         node valorsueldo = doc.createtextnode(string.valueof(float.valueof(legajo)*2));         sueldo.appendchild(valorsueldo);          node cnc = doc.getelementsbytagname("cnc").item(0);          cnc.appendchild(sueldo);          domsource source = new domsource(doc);         transformerfactory tf = transformerfactory.newinstance();         transformer t = tf.newtransformer();          t.setoutputproperty(outputkeys.indent, "yes");         t.setoutputproperty("{http://xml.apache.org/xslt}indent-amount","2");           fileoutputstream fos = new fileoutputstream("c:\\empleado.xml");         streamresult sr = new streamresult(fos);          t.transform(source,sr);              }       else           throw new exception("no hay archivo xml con ese nombre en el directorio");     }     catch (exception e)      {       system.out.println(e.getmessage());     } } 

}

thank in advance guys, i'll appreciate here!

assuming input file same output you've shown without sueldo element, initial cnc element has five child nodes far dom concerned

• the whitespace text node (newline , 4 spaces) between <cnc> , <nombre>
• the nombre element node
• the whitespace text node (newline , 4 spaces) between </nombre> , <legajo
• the legajo element node
• the whitespace text node (newline , two spaces) between </legajo> , </cnc>

you inserting sueldo element after final text node, produces

  <cnc>     <nombre>brian</nombre>     <legajo antiguedad="1 año, 7 meses">2134</legajo>   <sueldo>4268.0</sueldo></cnc> 

and indent output property moves closing </cnc> tag next line, aligned opening one. auto indentation right thing need remove all whitespace-only text nodes initial tree.

alternatively, forget auto-indentation , - instead of adding sueldo last child of cnc (after final text node), instead add newline-and-four-spaces text node after legajo (i.e. before last text node) , add sueldo element after that.

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as alternative approach entirely, consider doing transformation in xslt rather using dom apis

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/xsl/transform" version="1.0">   <!-- ignore whitespace-only text nodes in input -->   <xsl:strip-space elements="*"/>   <!-- , re-indent output -->   <xsl:output method="xml" indent="yes" />    <!-- copy verbatim except otherwise specified -->   <xsl:template match="@*|node()">     <xsl:copy><xsl:apply-templates select="@*|node()" /></xsl:copy>   </xsl:template>    <!-- cnc elements, add sueldo last child -->   <xsl:template match="cnc">     <xsl:copy>       <xsl:apply-templates select="@*|node()" />       <sueldo><xsl:value-of select="legajo * 2" /></sueldo>     </xsl:copy>   </xsl:template> </xsl:stylesheet> 

which either run using transformerfactory api java code or using standalone command-line xslt processor.