Java InputStreamReader: Purpose and Usage

The InputStreamReader is a character stream primarily used to convert byte streams into character streams. In JAVA, byte streams are input/output streams that operate at the byte level, while character streams operate at the character level. The InputStreamReader converts byte streams into character streams using a specified character encoding, allowing data to be read by characters rather than bytes, making it easier to handle text files and text data. Common character encodings include UTF-8, GBK, ISO-8859-1, and others.