java8--sorting sort

With the JAVA8, it is convenient to make the elements in the list in a positive sequence, flashback operation ~

• Sort the numbers

// sort the numbers List<integer> nums = arrays.aslist (3,1,5,2,9,8,4,10,6,7);   // Reverseorder Reverse System.err.println ("reverse:" +nums); // Reverse: [9, 8, 7, 6, 5, 4, 3, 2, 1] Nums.sort (Comparator.naturalorder ()); // Naturalorder Natural sort i.e.: positive sequence SYSTEM.ERR.PRINTLN ("Positive order:" +nums); // positive Order: [1, 2, 3, 4, 5, 6, 7, 8, 9, ten]

• Sort by an attribute of an object

 //Sort by an attribute of an object: for example, agelist<user> users =NewArraylist<>(); Users.add (NewUser ("U1", 22)); Users.add (NewUser ("U2", 18)); Users.add (NewUser ("U3", 35)); Users.add (NewUser ("U4", 16)); Users.add (NewUser ("U5", 40));/**
* O1,O2 indicates the object to be compared,
* Positive order: O1.getage (). CompareTo (O2.getage ())
* Reverse: O2.getage (). CompareTo (O1.getage ())
**/Users.sort ((O1, O2) o1.getage (). CompareTo (O2.getage ())); System.err.println ("Age Positive sequence:" +users);//Age sequence: [user{name= ' U4 ', age=16}, User{name= ' U2 ', age=18}, User{name= ' U1 ', age=22}, User{name= ' U3 ', age=35}, user{ Name= ' U5 ', age=40}]Users.sort (O1, O2)  - o2.getage (). CompareTo (O1.getage ())); System.err.println ("Age Reverse:" +users);//Age Reverse: [user{name= ' U5 ', age=40}, User{name= ' U3 ', age=35}, User{name= ' U1 ', age=22}, User{name= ' U2 ', age=18}, user{ Name= ' U4 ', age=16}]

java8--sorting sort