In Java, the PrintStream class is a subclass of FilterOutputStream that provides methods for printing various data types to an output stream. It is used to print formatted representations of objects to a text-output stream.

Here are some of the commonly used methods of the PrintStream class:

1. print(): This method prints an object to the output stream.

2. println(): This method prints an object to the output stream, followed by a newline character.

3. print(boolean x): This method prints a boolean value to the output stream.

4. print(char x): This method prints a character to the output stream.

5. print(int x): This method prints an integer to the output stream.

6. print(float x): This method prints a float value to the output stream.

7. print(double x): This method prints a double value to the output stream.

8. printf(String format, Object... args): This method prints a formatted string to the output stream using the specified format string and arguments.

9. append(CharSequence csq): This method appends the specified character sequence to the output stream.

10. append(CharSequence csq, int start, int end): This method appends a subsequence of the specified character sequence to the output stream.

11. append(char c): This method appends the specified character to the output stream.

12. flush(): This method flushes the output stream.

13. close(): This method closes the output stream and releases any system resources associated with it.

It's important to note that the PrintStream class should be used with caution when printing to untrusted destinations, as it can be vulnerable to malicious attacks if the data is not properly validated. Additionally, when using a PrintStream, you should always make sure to call the flush() method or close the stream to ensure that all the data is written to the underlying stream.