Self-taught articles-single case mode (10)

single case mode: divided into idle type and a hungry man type. The principle is simply that a class can only create one object and provide the user with it.

a hungry man type: 1. Create a Private object

2. Building a private constructed object

3. Provide a way to call this object externally

public class Singletest {

public static void Main (String [] args) {

Single S1 =single.getinstance ();

}

}

Class Single {

private static Single S = new single ();

Private single () {}

public static single getinstance () {

return s;

}

}

Lazy Type: public class Singletest {

public static void Main (String [] args) {

Single S1 =single.getinstance ();

}

}

Class single{

private static single s = null; Create a reference variable, but delay the creation of a class,

Private single () {}

public static single getinstance () {

if (s==null) {

Synchronized (Single.class) {//Lock to avoid creating multiple objects

if (s==null)

S=new single (); Delaying the establishment of objects in this place

}

}

return s;

}

}