I've been doing some research for a blog post regarding java.io.BufferedInputStream and buffers. Apparently, over the years, the default has grown from a measly 512 bytes to 8192 bytes as of (presumptuously) Sun's Java 7 implementation, and was even explicitly specified in the JavaDocs in JDK 1.1.8. My question has also brought up questions of who/what deciedes what the default should be--it's not as black-n-white as I had expected.
I am curious as to what the default buffer size has been at each version release, and what it may be in other, exotic JVMs. So far I've tracked it down, via source code, JavaDocs or Sun bug reports for 1.0, 1.1, 1.4, Java 5, Java 6 and (presumptuously again) Sun's Java 7 JVM.
What I've failed to turn up is this value for
- Sun JDK 1.2's JVM implementation
- Sun JDK 1.3's implementation
- Any other implementation's value (like IBM or something else)
So, I was wondering what those values are and where I could find a reference to them?
Or, that baring, if any SOpedians out there might have access to one of these installations. If so, could you compile and run the below code, and then report back here? Or, do you know of
import java.io.BufferedInputStream;
import java.io.InputStream;
public class BufferSizeDetector extends BufferedInputStream {
public static void main(String[] args) {
BufferSizeDetector bsd = new BufferSizeDetector(null);
System.err.println(System.getProperty("java.version"));
System.err.println(bsd.getBufferSize());
}
public BufferSizeDetector(InputStream in) {
super(in);
}
public int getBufferSize() {
return super.buf.length;
}
}