Java Basic Knowledge Enhancement Collection Framework note 60:map collection of TreeMap (treemap<student,string>) case

1. The case of TreeMap (treemap<student,string>)

2. Case code:

(1)Student. Java:

1  Packagecn.itcast_04;2 3  Public classStudent {4     PrivateString name;5     Private intAge ;6 7      PublicStudent () {8         Super();9     }Ten  One      PublicStudent (String name,intAge ) { A         Super(); -          This. Name =name; -          This. Age =Age ; the     } -  -      PublicString GetName () { -         returnname; +     } -  +      Public voidsetName (String name) { A          This. Name =name; at     } -  -      Public intGetage () { -         returnAge ; -     } -  in      Public voidSetage (intAge ) { -          This. Age =Age ; to     } +}

(2) test class TreeMapDemo2, as follows:

1  Packagecn.itcast_04;2 3 ImportJava.util.Comparator;4 ImportJava.util.Set;5 ImportJava.util.TreeMap;6 7 /*8 * treemap<student,string>9 * Key: StudentTen * Value: String One  */ A  Public classTreeMapDemo2 { -      Public Static voidMain (string[] args) { -         //To create a collection object theTreemap<student, String> TM =NewTreemap<student, string>( -                 NewComparator<student>() { - @Override -                      Public intCompare (Student s1, Student S2) { +                         //Main conditions -                         intnum = S1.getage ()-s2.getage (); +                         //Secondary Condition A                         intnum2 = num = = 0?s1.getname (). CompareTo ( at S2.getname ()): num; -                         returnnum2; -                     } -                 }); -  -         //Create student Objects inStudent S1 =NewStudent ("Koh Phangan", 30); -Student s2 =NewStudent ("Willow Xia Hui", 35); toStudent s3 =NewStudent ("Tong Pak Fu", 33); +Student S4 =NewStudent ("燕青", 32); -Student S5 =NewStudent ("Tong Pak Fu", 33); the  *         //Storage Elements $Tm.put (S1, "Song Dynasty");Panax NotoginsengTm.put (S2, "Yuan Dynasty"); -Tm.put (S3, "Ming Dynasty"); theTm.put (S4, "Qing Dynasty"); +Tm.put (S5, "Han Dynasty"); A  the         //Traverse +Set<student> set =Tm.keyset (); -          for(Student key:set) { $String value =Tm.get (key); $System.out.println (Key.getname () + "---" + key.getage () + "---" -+value); -         } the     } -}

Run the effect as follows:

Java Basic Knowledge Enhancement Collection Framework note 60:map collection of TreeMap (treemap<student,string>) case