What is the purpose of a ByteArrayOutputStream in Java?

The ByteArrayInputStream class in Java is a stream that reads data from a byte array. It wraps the byte array into an input stream object, allowing you to read byte data from it using read methods.

The main purpose of the ByteArrayInputStream class includes:

1. Read byte array data: You can use the read() method to read data from a byte array byte by byte.
2. Reading a specified length of byte array data: You can use the read(byte[] b, int off, int len) method to read a specified length of byte data from a byte array and store it in the given byte array.
3. Skip a specified number of bytes in the byte array: You can skip a specified number of bytes in the byte array using the skip(long n) method.
4. Marking and resetting: You can set a mark at the current position using the mark(int readAheadLimit) method, and return to that mark using the reset() method.

The ByteArrayInputStream class is commonly used in scenarios where data needs to be read from a byte array, such as reading image data or compressed data from a byte array.