FileStreams

Question

Hello,
the following class can inflate and deflate files. The in/deflated file overrides the old one. But I've encountered a problem. This class first writes a file into a byteArray. Next it is being in/deflated and written to the disk. But with large files(>30mb on my computer), I get a memory overload. Does anyone have any suggestions?
Thanks in advance,
Wouter
This is the code:
package koepelFileCompressor;
import java.io.*;
import java.util.zip.*;
public class koepelFileHandler {
     static final int BUFFER = 4096;
     public koepelFileHandler(){
          //lege constructor
     public byte[] makeByteArray(File file){
          byte data[] = new byte[BUFFER];
          try{
               BufferedInputStream fileNaarByte = null;
               FileInputStream fi = new FileInputStream(file);
               fileNaarByte = new BufferedInputStream(fi, BUFFER);
               ByteArrayOutputStream out = new ByteArrayOutputStream();
               int count;
               while((count = fileNaarByte.read(data, 0, BUFFER)) != -1) {
               out.write(data, 0, count);
               fileNaarByte.close();
               return out.toByteArray();
          catch(Exception e){
               e.printStackTrace();
               return data;
     public void pakIn(String fileName){
          try{
               Deflater compressor = new Deflater();
          compressor.setLevel(Deflater.BEST_COMPRESSION);
               compressor.setInput(makeByteArray(new File(fileName)));
               BufferedOutputStream inflateTo = new BufferedOutputStream(new FileOutputStream(new File(fileName)));
          compressor.finish();
               byte[] buf = new byte[BUFFER];
               while (!compressor.finished()) {
          int countIt = compressor.deflate(buf);
          inflateTo.write(buf, 0, countIt);
               inflateTo.close();
          catch(Exception e){
               e.printStackTrace();
     public void pakUit(String fileName){
          try {
               Inflater decompressor = new Inflater();
          decompressor.setInput(makeByteArray(new File(fileName)));
          BufferedOutputStream deflateTo = new BufferedOutputStream(new FileOutputStream(new File(fileName)));
          byte[] buf = new byte[BUFFER];
          while (!decompressor.finished()) {
     int count = decompressor.inflate(buf);
     deflateTo.write(buf, 0, count);
          deflateTo.close();
     catch(Exception e) {
          e.printStackTrace();
}

Answer 1

One option is to increase the Java heap size by doing
java -XmxBIGGERNUMBER yourRunnableClassName
Also, you could analyze your code to see if you can set to null some large data structures
after you're done using them, before you build some other large data structures. Call System.gc() a few times in succession after you've set the structure(s) to null, and it will clean up the memory soon afterwards. Though this will slow down the performance of the program somewhat.
Hope this helps,
Corrine
Hello,
the following class can inflate and deflate files. The
in/deflated file overrides the old one. But I've
encountered a problem. This class first writes a file
into a byteArray. Next it is being in/deflated and
written to the disk. But with large files(>30mb on my
computer), I get a memory overload. Does anyone have
any suggestions?
Thanks in advance,
Wouter
This is the code:
package koepelFileCompressor;
import java.io.*;
import java.util.zip.*;
public class koepelFileHandler {
     static final int BUFFER = 4096;
     public koepelFileHandler(){
          //lege constructor
     public byte[] makeByteArray(File file){
          byte data[] = new byte[BUFFER];
          try{
               BufferedInputStream fileNaarByte = null;
               FileInputStream fi = new FileInputStream(file);
fileNaarByte = new BufferedInputStream(fi,
i, BUFFER);
ByteArrayOutputStream out = new
ew ByteArrayOutputStream();
               int count;
while((count = fileNaarByte.read(data, 0, BUFFER))
)) != -1) {
               out.write(data, 0, count);
               fileNaarByte.close();
               return out.toByteArray();
          catch(Exception e){
               e.printStackTrace();
               return data;
     public void pakIn(String fileName){
          try{
               Deflater compressor = new Deflater();
          compressor.setLevel(Deflater.BEST_COMPRESSION);
compressor.setInput(makeByteArray(new
ew File(fileName)));
BufferedOutputStream inflateTo = new
ew BufferedOutputStream(new FileOutputStream(new
File(fileName)));
          compressor.finish();
               byte[] buf = new byte[BUFFER];
               while (!compressor.finished()) {
          int countIt = compressor.deflate(buf);
          inflateTo.write(buf, 0, countIt);
               inflateTo.close();
          catch(Exception e){
               e.printStackTrace();
     public void pakUit(String fileName){
          try {
               Inflater decompressor = new Inflater();
decompressor.setInput(makeByteArray(new
y(new File(fileName)));
BufferedOutputStream deflateTo = new
= new BufferedOutputStream(new FileOutputStream(new
File(fileName)));
          byte[] buf = new byte[BUFFER];
          while (!decompressor.finished()) {
     int count = decompressor.inflate(buf);
     deflateTo.write(buf, 0, count);
          deflateTo.close();
     catch(Exception e) {
          e.printStackTrace();