java.lang.Byte Class in Java

The java.lang.Byte class in Java is a wrapper class that encapsulates a single byte value (8 bits) as an object. It provides a way to work with byte values in an object-oriented manner. It also allows us to perform various operations and utilize methods provided by the class.

Following are some key points about the Byte class:

1. Wrapper Class: The Byte class belongs to the group of wrapper classes in Java, which provide an object representation for primitive data types. In the case of Byte, it wraps the primitive data type byte.
2. Constructor: The Byte class provides two constructors – one that takes a byte value as an argument and another that takes a String representation of a byte. For example:

Byte byteValue = new Byte((byte) 10);
Byte byteFromString = new Byte("5");

Remember that the above constructors are deprecated now. Hence, to convert from primitive byte to Object type then we can use the method: valueOf(byte b) and to convert from String to byte we can use valueOf("5"). Let's see an example below:

Byte byteValue = Byte.valueOf(10);
Byte byteFromString = Byte.valueOf("5");

3. Comparison and Conversion: The Byte class offers methods for comparing and converting byte values, such as compareTo, equals, and valueOf.
4. Constants: It defines constants like MIN_VALUE and MAX_VALUE, which represent the minimum and maximum values that a byte can hold.
5. Methods: The Byte class provides methods to convert bytes to other data types (e.g., intValue(), doubleValue()), get the byte value as a String (toString()), and more.
6. Autoboxing and Unboxing: With autoboxing, we can automatically convert a primitive byte into a Byte object when needed, and vice versa with unboxing.
7. Immutability: Byte objects are immutable, meaning their values cannot be changed after creation. If we need to modify a byte value, we’ll need to create a new Byte object.
8. Use Cases: The Byte class is commonly used when byte values need to be stored in collections that require objects, or when byte values need to be passed as parameters to methods that accept objects.

Following is an example of using the Byte class:

Byte byteValue =  7;
System.out.println("Byte value: " + byteValue);
int intValue = byteValue.intValue();
System.out.println("Converted to int: " + intValue);

In summary, the java.lang.Byte class provides a convenient way to work with byte values in an object-oriented context, offering methods for comparison, conversion, and manipulation while adhering to the principles of Java’s class hierarchy.