Java InputStream reading problem

Question

I have a Java class, where I\'m reading data in via an InputStream

    byte[] b = null;
    try {
        b = new byte[in.available()];
        in.read(b);
          


        

Answer 1

read() will return -1 when the InputStream is depleted. There is also a version of read which takes an array, this allows you to do chunked reads. It returns the number of bytes actually read or -1 when at the end of the InputStream. Combine this with a dynamic buffer such as ByteArrayOutputStream to get the following:

InputStream in = ...
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int read;
byte[] input = new byte[4096];
while ( -1 != ( read = in.read( input ) ) ) {
    buffer.write( input, 0, read );
}
input = buffer.toByteArray()

This cuts down a lot on the number of methods you have to invoke and allows the ByteArrayOutputStream to grow its internal buffer faster.