There are eight primitive data types in Java including non-decimal types like byte, short, int, long and decimal types like float and double. The boolean type represents one bit of information with true and false values, while char represents a single 16-bit Unicode character. Reference data types are used to access objects by referencing variables created with class constructors. Java also supports literals to represent fixed values in code and escape sequences for strings and characters.

1. Primitive Data Types
There are eight primitive data types supported by Java.
Primitive data types are predefined by the language and
named by a key word.
Primitive types are not objects;
so does not have any methods for further processing.

2. Non Decimal
● byte - signed 8-bit
● short - signed 16-bit
● int - signed 32-bit
● long - signed 64-bit

3. Decimal
● float - single-precision 32-bit
● double - double-precision 64-bit

4. boolean
● boolean data type represents one bit of information
● There are only two possible values : true and false.
● Default value is false

5. char
● 16-bit Unicode character
● Minimum value is ‘u0000′ (or 0).
● Maximum value is ‘uffff’ (or 65,535 inclusive)

6. Reference Data Types
Reference variables are created using defined
constructors of the classes.
They are used to access objects. These variables are
declared to be of a specific type that cannot be changed.

7. Java Literals
A literal is a source code representation of a fixed value.

8. Java language supports few special escape
sequences for String and char literals as well.