According to the Java documentation, any implementation of the InputSteam.read() method is supposed to read the next byte of data from
the input stream. The value byte must be an int in the range 0 to 255. If no byte is available because the end of the stream has been
reached, the value -1 is returned.
But in Java, the byte primitive data type is an 8-bit signed two’s complement integer. It has a minimum value of -128 and a maximum
value of 127. So by contract, the implementation of an InputSteam.read() method should never directly return a byte
primitive data type. A conversion into an unsigned byte must be done before by applying a bitmask.
Noncompliant code example
@Override
public int read() throws IOException {
if (pos == buffer.length()) {
return -1;
}
return buffer.getByte(pos++); // Noncompliant, a signed byte value is returned
}
Compliant solution
@Override
public int read() throws IOException {
if (pos == buffer.length()) {
return -1;
}
return buffer.getByte(pos++) & 0xFF; // The 0xFF bitmask is applied
}
