Heap size increases when writing XML to the File

[batuk chatuk]

I am converting an object (ArrayList) in XML and then storing that XML as a file on local machine. When there are large number of data, the XML takes too long to write in a File or doesnt write at all (gives some exception).

xmlSource = xmlConverter.convert(object); // object here is no.of ArrayLists..

FileWriter fw = new FileWriter(f);
fw.write(xmlConverter.getXML());

fw.write() takes too much time. Is there any other way which doesnt eat up so much memory ???

[David O'Meara]

wrap it in a BufferedWriter is the first step

PrintWriter out
= new PrintWriter(new BufferedWriter(new FileWriter("foo.out")));

[batuk chatuk]

thanks!!!

File f = new File("foo.xml");
PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(f)));
pw.write(xmlConverter.getXML(obj));

Using BW does speed up the process by almost 40%, although the PC remains in a numb state during that time..but it does work..

I m afraid this solution is not gonna be enough as there are around 100k entries on Production env at max.. ( I checked above sol. on 50000 records..)

Is there any possibility that i split the records and then in chunks i add them in "same file". (dont want to create more than 1 XML for one page..)

Thanks again...

[batuk chatuk]

Its Done!!!

File writing is happening totally with all data at a time in above code..
So this is the answer to better and memory friendly code...

xmlSource = xmlConverter.convert(obj);
BufferedReader bufferedReader = new BufferedReader(xmlSource.getReader());
PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(f)));
int count = 0;
int buffer=1024;
char[] c1=new char[buffer];
while((count = bufferedReader.read(c1, 0, buffer)) != -1){
pw.write(c1, 0, count);
}
pw.flush();
pw.close();

[batuk chatuk]

For 100K records or more the above code didnt work on my machine.. ( i had kept JVM Heap size to Max. 1300K.. )
The reason was the XMLConverter was not able to convert that much data into XML So i wrote the code to divide all the ArrayLists in chunks and then convert them and write them into the same file..

FileWriter fw = new FileWriter(new File("foo.xml , true);

the flag in the constructor is for Appending the new data to same file..
and so file can be generated without any trouble..

Best Regards