Java DocumentBuilder - wrong indentation in XML file -

i try write simple xml file in java using documentbuilder. expected xml file this:

<outer>      <inner>           <element name="web"/>           <element name="web"/>           <element name="web"/>      </inner> </outer> 

but generates this:

<outer>      <inner>           <element name="web"/>           <element name="web"/>      <element name="web"/>      </inner> </outer> 

why third element not have same indentation other 2 elements? note: read xml file again simulate method in project, read xml file, add 1 element , save xml file. here code:

import org.w3c.dom.document; import org.w3c.dom.element; import org.xml.sax.saxexception;  import javax.xml.parsers.documentbuilder; import javax.xml.parsers.documentbuilderfactory; import javax.xml.parsers.parserconfigurationexception; import javax.xml.transform.*; import javax.xml.transform.dom.domsource; import javax.xml.transform.stream.streamresult; import java.io.file; import java.io.ioexception;  public class main {     private static string filepath = "/tmp/xmltest.xml";     private static documentbuilderfactory docfactory;     private static documentbuilder docbuilder;     private static transformerfactory transformerfactory;     private static transformer transformer;      public static void main(string[] args) throws ioexception, saxexception, parserconfigurationexception, transformerconfigurationexception, transformerexception{         docfactory = documentbuilderfactory.newinstance();         docbuilder = docfactory.newdocumentbuilder();         transformerfactory= transformerfactory.newinstance();         transformer = transformerfactory.newtransformer();         transformer.setoutputproperty(outputkeys.encoding, "utf-8");         transformer.setoutputproperty(outputkeys.indent, "yes");         transformer.setoutputproperty("{http://xml.apache.org/xslt}indent-amount", "1");          // creating xml file structure         document document = docbuilder.newdocument();         element rootelement = document.createelement("outer");         document.appendchild(rootelement);          element inner = document.createelement("inner");         rootelement.appendchild(inner);          // write xml file         write(document);          // read xml file         document = docbuilder.parse(filepath);         element root = document.getdocumentelement();         element innerelement = (element)root.getelementsbytagname("inner").item(0);          // add element         element e = document.createelement("element");         e.setattribute("name", "web");         innerelement.appendchild(e);          // add element         e = document.createelement("element");         e.setattribute("name", "web");         innerelement.appendchild(e);          // write xml file         write(document);          // read xml fil         document = docbuilder.parse(filepath);         root = document.getdocumentelement();         innerelement = (element)root.getelementsbytagname("inner").item(0);          // add element         e = document.createelement("element");         e.setattribute("name", "web");         innerelement.appendchild(e);          // write xml file         write(document);     }      private static void write(document document) throws transformerexception {         domsource source = new domsource(document);         streamresult result = new streamresult(new file(filepath));         transformer.transform(source, result);     } } 

the text nodes in xmlfile used indententation treated data. because of indentation going toss. can fix below:

private static void removeemptytext(node node){     node child = node.getfirstchild();     while(child!=null){         node sibling = child.getnextsibling();         if(child.getnodetype()==node.text_node){             if(child.gettextcontent().trim().isempty())                 node.removechild(child);         }else             removeemptytext(child);         child = sibling;     } }  private static void write(document document) throws transformerexception {     removeemptytext(document.getdocumentelement());     domsource source = new domsource(document);     streamresult result = new streamresult(new file(filepath));     transformer.transform(source, result); } 

here removing indentation text nodes dom before writing file.