How to specify where to save string in file - file

Question

How to save string to file to specify place ? I use path << 'string' to save, but it give it on end of file. In destination to xml(path) file have </databaseChangeLog>. I want to save to file before that word occurs.
There is java solution click, but it is static line. My file will be dynamic, I don't know with line it will be.
def add_to_version() {
def path = new File('C:/groovy/version-1.xml')
def branchId = "Promt"
def lineCount = 0
def count = path.eachLine { line ->
if(line.contains('<include file="' + branchId + '/' + branchId + '.xml" ')){
wordCount++
}else if(lineCount == 1 ){
println "package is there"
}
}
if(lineCount == 0){
path << '<include file="' + branchId + '/' + branchId + '.xml" ' + 'relativeToChangelogFile="true"/>'
}
}
code above do that :
and I want to get xml like that :

Answer 1

you can use xml parser like this:
def add_to_version(String branchId) {
def path = new File('C:/groovy/version-1.xml')
def xml = new XmlParser().parse(path)
xml.appendNode("include", [
file:"${branchId}/${branchId}.xml",
relativeToChangelogFile:"true"
])
groovy.xml.XmlUtil.serialize(xml, path.newOutputStream())
}
this variant will not keep the xml formatting and comments
however xml will be valid