How To Write Large Data File In Java

Below program explains how to write large data files in java.

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;

public class FileWriting {

public static void main(String[] args) {

System.out.println(“Before Total Memory = “

+ Runtime.getRuntime().totalMemory());

System.out.println(“Before Free Memory = “

+ Runtime.getRuntime().freeMemory());

BufferedOutputStream fileOutputStream = null;

BufferedInputStream aTypeFileIn = null;

String bTypeFileName = “E:\\Test\\BType.xml”;

int fileread= 1024*1024 ;

byte fileBuffer[] = new byte[1024 * 1024];

int byteOfRead = 0;

int offsetOfFile = 0;

String aTypeFile = “E:\\Test\\AType.xml”;

while(true)

{

try {

fileOutputStream = new BufferedOutputStream( new FileOutputStream( bTypeFileName ) );

if( fileOutputStream == null ) {

fileOutputStream = new BufferedOutputStream( new FileOutputStream( bTypeFileName ) );

}

aTypeFileIn = new BufferedInputStream(

new FileInputStream(aTypeFile));

} catch (FileNotFoundException fileNotFound) {

}

do {

try {

byteOfRead = aTypeFileIn.read(fileBuffer, offsetOfFile,fileread);

} catch (IOException ioError) {

break;

}

if (byteOfRead != -1) {

try {

fileOutputStream

.write(fileBuffer, offsetOfFile, byteOfRead);

} catch (IOException ioError) {

break;

}

}

} while (byteOfRead != -1);

try

{

try {

aTypeFileIn.close() ;

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

finally

{

try {

fileOutputStream.flush();

fileOutputStream.close();

System.out.println(“After Total Memory = “

+ Runtime.getRuntime().totalMemory());

System.out.println(“After Free Memory = “

+ Runtime.getRuntime().freeMemory());

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

}