1 package Aug11.Collection;  2   3 import java.util.*;  4   5 public class Test4 {  6     public static Set set = new HashSet();  7   8     public static void main(String[] args) {  9         Scanner reader = new Scanner(System.in); 10  11         while (true) { 12             System.out.println("---------------------"); 13             System.out.println("1. Add student"); 14             System.out.println("2. Display details of all students"); 15             System.out.println("3. Search student"); 16             System.out.println("4. Find out highest marks"); 17             System.out.println("5. Exit"); 18             System.out.println("---------------------"); 19             int n = reader.nextInt(); 20             switch (n) { 21             case 1: 22                 addStu(); 23                 break; 24             case 2: 25                 displayAllStu(); 26                 break; 27             case 3: 28                 searchStu(); 29                 break; 30             case 4: 31                 findHighestMarks(); 32                 break; 33             case 5: 34                 Exit(); 35                 break; 36             } 37         } 38  39     } 40  41     private static void Exit() { 42         System.out.println("Exit Success!"); 43         System.exit(0); 44  45     } 46  47     private static void findHighestMarks() { 48         Student stu; 49         int max = 0; 50         Iterator itr = set.iterator(); 51         while (itr.hasNext()) { 52             stu = (Student) itr.next(); 53             if (stu.getPercentage() > max) { 54                 max = stu.getPercentage(); 55             } 56  57         } 58         System.out.println("The  highest mark is " + max); 59  60     } 61  62     private static void searchStu() { 63         Scanner reader = new Scanner(System.in); 64         boolean flag = false; 65         System.out.println("Enter the student‘s name:"); 66         String name = reader.nextLine(); 67         Iterator itr = set.iterator(); 68         while (itr.hasNext()) { 69             Student stu = (Student) itr.next(); 70             if (stu.getName().equals(name)) { 71                 System.out.println(stu.getName() + ":" + stu.getPercentage()); 72                 return; 73             } else{ 74                 flag=false; 75             } 76         } 77         if(!flag) 78         System.out.println("There has no such person"); 79     } 80  81     private static void displayAllStu() { 82         System.out.println("The information of all students:"); 83         Iterator itr = set.iterator(); 84         while (itr.hasNext()) { 85             Student stu = (Student) itr.next(); 86             System.out.println(stu.getName() + ":" + stu.getPercentage()); 87         } 88     } 89  90     private static void addStu() { 91         Scanner reader = new Scanner(System.in); 92         System.out.println("Enter student‘s name:"); 93         String name = reader.nextLine(); 94         System.out.println("Enter student‘s percentage:"); 95         int percentage = reader.nextInt(); 96         Student stu = new Student(name, percentage); 97         set.add(stu); 98     } 99 100 }101 102 // Student class103 104 class Student {105     String name;106     int percentage;107     public Student(){108         109     }110     public Student(String name, int percentage) {111         this.name = name;112         this.percentage = percentage;113 114     }115 116     public String getName() {117         return name;118     }119 120     public void setName(String name) {121         this.name = name;122     }123 124     public int getPercentage() {125         return percentage;126     }127 128     public void setPercentage(int percentage) {129         this.percentage = percentage;130     }131 132 }