Java Time related content learning (5) SimpleDateFormat Introduction

Introduce SimpleDateFormat.

SimpleDateFormat Introduction

SimpleDateFormat is a tool that formats date and parses date strings. Its most common use is to format date in the specified format, and then we use the string that can be obtained after the date is formatted.

More strictly speaking, SimpleDateFormat is a specific class that formats and parses dates in a way that is relevant to the locale. It allows for formatting (date-> text), parsing (text-> date), and normalization.

The SimpleDateFormat constructor:

Constructor SimpleDateFormat () SimpleDateFormat (string pattern) SimpleDateFormat (string template, DateFormatSymbols value) SimpleDateFormat (String template, Locale Locale)//non-constructor void Applylocalizedpattern (Str ing template) void Applypattern (String template) Object clone () bool  Ean equals (object) stringbuffer format (date date, StringBuffer buffer,                             FieldPosition fieldpos) Attributedcharacteriterator Formattocharacteriterator (Object object) Date Get2digityearstart () DateFormatSymbols getdateformatsymbols () int ha Shcode () Date parse (string string, parseposition position) void SE                           T2digityearstart (date date) void Setdateformatsymbols (dateformatsymbols value) String TolocaliZedpattern () String Topattern () 

SimpleDateFormat Simple demonstration:

New Date object, Time is 2013-09-19

Date date = new Date (113,8,19);

Creates a new SimpleDateFormat object and sets the "format mode" for SDF

SimpleDateFormat SDF = new SimpleDateFormat ("Yyyy-mm-dd");

Formats date with SDF and returns a string.

String str = sdf.format (date);

SimpleDateFormat Related Format description

Date and time patterns

Date and time formats are specified by date and time pattern strings. In a date and time pattern string, the unnamed letters ' a ' to ' Z ' and ' a ' to ' Z ' are interpreted as pattern letters, which are used to represent a date or time string element. The text can be enclosed in single quotes (') to avoid interpretation. "" "represents single quotes. All other characters are not interpreted; they are simply copied to the output string when they are formatted, or they match the input string when parsing.

The following pattern letters are defined (all other characters ' a ' to ' Z ' and ' a ' to ' Z ' are preserved):