The ByteArrayInputStream class in Java provides several methods for reading data from an array of bytes. Some of the commonly used methods of the ByteArrayInputStream class are:

1. read() - Reads a single byte of data from the input stream and returns it as an integer in the range 0 to 255.

2. read(byte[] b) - Reads a sequence of bytes from the input stream into the byte array b and returns the number of bytes read.

3. read(byte[] b, int off, int len) - Reads up to len bytes of data from the input stream into the byte array b, starting at the specified offset off, and returns the number of bytes read.

4. available() - Returns the number of bytes that can be read from the input stream without blocking.

5. skip(long n) - Skips over and discards n bytes of data from the input stream.

6. mark(int readAheadLimit) - Marks the current position in the input stream.

7. reset() - Resets the input stream to the last marked position.

8. markSupported() - Returns a boolean indicating whether this input stream supports the mark and reset methods.

It's important to note that the behavior of these methods can vary depending on the specific implementation of the ByteArrayInputStream class. Additionally, the ByteArrayInputStream class is not thread-safe, so you should not use it in a multithreaded environment without taking appropriate precautions.

Overall, the ByteArrayInputStream class provides a flexible and efficient way of reading data from a byte array in Java, and the various methods it provides can be used to read data in a variety of different ways depending on your specific needs. By using the various methods of the ByteArrayInputStream class, you can read data from byte arrays in a variety of formats, including text data, binary data, and more.