gradle Property items not stable when update values - gradle

Question

I am trying to write a gradle code to save file versions to a meta property file. then if version updated, download new version and update the property file to avoid download again if version not updated.
Below code basic function works but two minor issues:
every time run ./gradle demo command, the first line in versions.txt will update a timestamp, I would like to disable it but not sure how.
Sometimes the item no version change will move location (e.g move from line 10 to line 15). That means the sequence of items in property file not stable. I would like only the version changed item get updated each time.
import groovy.json.JsonBuilder
apply plugin: 'java'
public String getDownloadedVersion(verFile,key) {
String value = null;
Properties prop = new Properties();
FileInputStream is = new FileInputStream(verFile);
prop.load(is);
value = prop.getProperty(key);
is.close();
return value
}
public void writeDownloadedVersion(verFile,key,value) {
Properties verProp = new Properties();
FileInputStream verInputStream;
FileOutputStream verOutputStream;
try {
if( verFile.exists() ) {
verInputStream = new FileInputStream(verFile)
verProp.load(verInputStream);
verInputStream.close();
}
verOutputStream = new FileOutputStream(verFile);
verProp.setProperty(key, value);
verProp.store(verOutputStream, null);
verOutputStream.close();
} catch(IOException e) {
System.out.println("exception " + e)
e.printStackTrace();
}
}
public boolean version_changed(verFile,file,version) {
def localVersion = getDownloadedVersion(verFile,file)
def found = false
if (localVersion != version) {
found = true
}
return found
}
tasks.register('demo') {
def fileLst = [
["abc","3.0"],
["def","4.0"],
["ghi","5.0"],
["jkl","2.0"],
["mno","1.0"],
["pqr","2.0"],
["stu","5.0"],
["vwx","2.0"],
]
doLast {
def verFile = new File(".", "versions.txt");
fileLst.each {file, version ->
if (version_changed(verFile,file,version)) {
System.out.println(file + " " + version)
//download version
writeDownloadedVersion(verFile,file,version)
}
}
}
}
Sample version.txt file:
#Thu Apr 28 16:40:02 CDT 2022
jkl=2.0
mno=1.0
pqr=2.0
abc=3.0
stu=5.0
def=4.0
vwx=2.0
ghi=5.0
If any other better solution, please help comment!