Strange behaviour of StringBuilder. Does not append the last char buffer.

Question

Below is the source code I am using to read a .gz file and convert it into plain text. I am using StringBuilder to store the whole plain text as a string and also writing the plain text to a file on disk. The writing on disk works perfectly fine, but for some weird reason, the StringBuilder leaves out the last part of the file (run it once and you'll see what I mean), when in fact both the StringBuilder and the OutputStreamWriter get their data from the same while loop.
import java.util.zip.GZIPInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
public class ProblemInStringBuilder
public static void main(String args[]) throws Exception
String inFilename, outFilename;
inFilename = "somefile.gz"; outFilename = "unzipped file.txt";
GZIPInputStream gzipInputStream = new GZIPInputStream(new FileInputStream(inFilename));
InputStreamReader myInputStreamReader = new InputStreamReader(gzipInputStream);
OutputStream out = new FileOutputStream(outFilename);
OutputStreamWriter myOutputStreamWriter = new OutputStreamWriter(out);
int len;
char[] charBuf = new char[1024];
StringBuilder builder = new StringBuilder();
while ((len = myInputStreamReader.read(charBuf)) > 0)
builder.append(charBuf);
myOutputStreamWriter.write(charBuf,0,len);
gzipInputStream.close();
myInputStreamReader.close();
myOutputStreamWriter.close();
System.out.println(builder); // <-- problem here. Leaves out the last part of the file.
}

Answer 1

builder.append(charBuf);
builder.append(charBuf, 0, len);From this error it seems to me you are getting extra characters at EOF (and possibly elsewhere), not missing characters.
gzipInputStream.close();
myInputStreamReader.close();Remove the first of those. The second one closes them both.