what is the best way to close a ByteArrayOutputStream?

Question

I need to optimize a application that uses too much heap memory. I'm having problem in close a ByteArrayOutputStream variable after using the same. I've tried to do using close() but it does not work. this is the code:

ByteArrayOutputStream zipOutTempStream = new ByteArrayOutputStream();
//arquivo.getZipStream() has the XML received by FTP.
//STreamEtils is the function who transfers the XML to zipOutTempStream
StreamUtils.copiarStream(arquivo.getZipStream(), zipOutTempStream);

            //Creating a new XML to write over this.
            File arquivo1 = new File("C:/XML.xml");
            if (arquivo1.exists()) {
                System.out.println("ele existe");
            } else {
                if (arquivo1.createNewFile()) {
                    System.out.println("arquivo criado");
                } else {
                    System.out.println("arquivo não criado");
                }
            }

            FileOutputStream arquivo2 = new FileOutputStream(arquivo1);
            //Copy the unziped XML to the new xml created.
            StreamUtils.copiarStream(StreamUtils                .uncompressXmlFromZipStream(new ByteArrayInputStream(zipOutTempStream.toByteArray())), arquivo2);
            arquivo.setZipStream(null);
            arquivo.setXmlStream(null)      
return arquivo;

Answer 1

You cannot close a ByteArrayOutputStream, since it's close() method is documented as

Closing a ByteArrayOutputStream has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

This output stream is backed by an array; it is NOT a buffered stream. If you feel it is using too much memory, you should output bytes directly to some endpoint, such as a file or a socket, using an appropriate OutputStream.