Java single-Instance design pattern

/*
Single Case design mode
Problem solved: You can guarantee that a class is in memory for the uniqueness of the object (the data is shared).
How to ensure the uniqueness of the object?
1, do not allow other programs to use,
2, create an instance of this in this class.
3, to provide a way for other programs to get the image.
Steps:
1, privatize the class constructor.
2. Create an object in this class by using new.
3, define a public method that will create the object to return.
*/

public class Test1 {

public static void Main (string[] args) {
//TODO auto-generated method stub

Test5 t1=test5.getinstance ();
Test5 t2=test5.getinstance ();
System.out.println (t1==t2);
T1.setnum (ten);
T2.setnum (+);
System.out.println (T1.getnum ());
System.out.println (T2.getnum ());
}

}
Class Test5
{
int num;
private static TEST5 t=new Test5 ();
Private Test5 ()
{

}
public static TEST5 getinstance ()
{
return t;
}
public int Getnum () {
return num;
}
public void setnum (int num) {
This.num = num;
}
}

Execution Result:

True
100
100

Java single-Instance design pattern