[Java] Format & Parse: Date, Number, Decimal, Message

1. Usage
   Specifies the protocol for classes which convert other objects or values, such as numeric values and dates, and their string representations
   
2. Package
   java.text.Format
   
3. Classes
   
   • Format
   • NumberFormat
   • DecimalFormatSymbols
   • DateFormat
   • SimpleDateFormat
   • MessageFormat
4. xxx