2015-08-06 Common Classes 2, regular expressions, threading

Date:

1 CST:2Date d =NewDate ();3 Dateformat:simpledateformat:4 5String str = "Yyyy-mm-dd HH:mm:ss E";6SimpleDateFormat SDF =NewSimpleDateFormat ();7 Sdf.applypattern (str);8 9  　　 //Date--> String time FormattingTenString d = Sdf.format (NewDate ()); One  A  　　 //String--- date parse the time back -Date d = sdf.parse (d);

Calendar:

1 abstract class: Calendar getinstance ();2     //The value of field is the constant in the Calendar class:3     intGetintfield): Gets the value of the specified field4 calendar.year;5                   . MONTH;6                   . DATE;7. Hour_of_day;//24 binary (. HOUR; 12 binary)8                   . MINUTE;9                   . SECOND;Ten  One use StringBuilder to spell a current system time; A  -Calendar C =calendar.getinstance (); -C.settime (NewDate ()); the  -StringBuilder SB =NewStringBuilder ("MYCST:"); -  -     inty =C.get (calendar.year); +     intm = C.get (calendar.month) + 1; -     intD =C.get (calendar.date); +     inth =C.get (calendar.hour_of_day); A     intMM =C.get (calendar.minute); at     ints =C.get (calendar.second); -  -Sb.append (y). Append ("Year"). Append (M). Append ("Month");......; -  -     voidsettime (Date D); - Date getTime (); in  - /* to offset of field value + */ - voidAddintFiledintoffset); the if offset is negative: indicates that the field value represented by the filed is shifted forward by offset; * If offset is a positive number: Indicates that the field value represented by the filed is shifted back offset; $ Panax NotoginsengSetintfield,intval): Set a value for a field -SetintYearintMonintDateintHourintMinints); the  +Time period settings: last two days; 2015-8-6:10:24:11 A  theStart Time Begintime:2015-8-5:00:00:00 +End Time Endtime:2015-8-6:23:59:59 -  $(Querytime >= beginTime) && (querytime <= endTime)

System:
void Arraycopy (object src, int pos, object dest, int destpos, int length);

void exit (int status);

System exit:

Always exit: System.exit (0);

　　1 means to meet an abnormal exit

To force garbage collection: void GC ();

void GC ();

static string getenv (string name)
Gets the specified environment variable value.

Runtime:

Process exec (String command)
Executes the specified string command in a separate process.

Runtime.getruntime (). EXEC ("notepad.exe Ooxx.java");
means to open the Ooxx.java file in Notepad

Regular Expressions:

belongs to the Java.util.regex package;

Pattern: Presentation Specification

Matcher: Represents the execution specification

String input = "data to be judged";

String regex = "Specification";

Pattern p = pattern.compile (regex);

Matcher m = p.matcher (Charsequence CS);

Boolean B = m.matches ();

Static Boolean matches (String regex, charsequence input)

　　
---------------------------------

b = pattern.matches (regex,input);
---------------------------------

String class:

　　　　Boolean matches (String regex) {

Return pattern.matches (Regex,this);
}
Boolean B = input.matches (regex);

There are two ways to create a startup thread:

　　1. How to Inherit
(1). Create a new class MyThread inherit Java.lang.Thread
(2). Overwrite public void Run () {}
(3). Create thread: MyThread t = new MyThread ();
(4). Start thread: T.start ();

2. Implementation method (recommended), using anonymous inner class to create
(1). Create a new class myrunnable implement Java.lang.Runnable interface
(2). Implement public void Run () {}
(3). Create thread: Thread t = new Thread (new myrunnable ());
(4). Start thread: T.start ();

the difference between the two: the inheritance mode of resources can not be shared, and later can not inherit other classes; Advantages: Simple.

Common methods:
String GetName ();
void SetName ();

Thread t = Thread.CurrentThread ();

Thread ();
Thread (String name);

Thread (Runnable target);
Thread (Runnable target, String name);

2015-08-06 Common Classes 2, regular expressions, threading