Read/Write

[Siva Kannan]

Is there anyway to read and write the file without loading the file into memory. I have to read and append the data to a large file (more than 2gb). When I try to use BufferedReader/BufferedWriter it loads the file into the memory (I believe) and I am facing some out of memory error. Please advice.

Thanks
Siva.

[Wouter Oet]

I believe that this can be done with a RandomAccessFile.

[Rob Spoor]

Siva Kannan wrote:When I try to use BufferedReader/BufferedWriter it loads the file into the memory (I believe)

No it doesn't. It stores a little portion, but definitely not the entire file. Are you sure it's not you that stores the entire file? You shouldn't, as you will only need a few (usually one) lines at a time.

Wouter: RandomAccessFile can be used for binary files, but for text files it's not really good (ASCII files can be handled but I wouldn't go any further).

[Siva Kannan]

Thanks for the reply Rob and Wouter.

I have a small clarification in the below code Rob.

Consider I have a 2gb text file and I need to append something at the end of the file.

FileOutputStream fis = new FileOutputStream(file);
OutputStreamWriter osw = new OutputStreamWriter(fis);
BufferedWriter bw = new BufferedWriter(osw);
bw.append("Lots there to learn");
bw.close();

For the above code when I create file output stream, don't the JVM load the whole file into the memory atleast temporarily? Please correct me if i am wrong.

Thanks Again.

[Rob Spoor]

FileOutputStream and FileWriter have constructors that allow you to append to the file instead of overwriting it.