public class Student {

    /**学号、姓名、性别、年龄*/

    private int id;

    private String name;

    private char sex;

    private int age;

    public Student(int id, String name, char sex, int age) {

        super();

        this.id = id;

        this.name = name;

        this.sex = sex;

        this.age = age;

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public char getSex() {

        return sex;

    }

    public void setSex(char sex) {

        this.sex = sex;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

}

 import java.io.BufferedReader;

 import java.io.IOException;

 import java.io.InputStreamReader;

 import java.util.HashMap;

 import java.util.Set;

 public class Test4 {

     /**

      * @param args

      */

     public static void main(String[] args) {

         Student student1 = new Student(001, "张三", '男', 20);

         Student student2 = new Student(002, "王舞", '女', 21);

         HashMap<Integer, Student> map = new HashMap<Integer, Student>();

         map.put(student1.getId(), student1);

         map.put(student2.getId(), student2);

         System.out.println("学生信息如下：");

         print(map);

         System.out.println();

         while (true) {

             System.out

                     .println("请选择你要操作的方式：\n学生信息增加请输入：1 学生信息检索请输入：2 学生信息删除请输入：3 退出请输入：4");

             BufferedReader input = new BufferedReader(new InputStreamReader(

                     System.in));

             try {

                 switch (Integer.parseInt(input.readLine())) {

                 // 增加学生信息

                 case 1:

                     System.out.println("请输入要增加的学生信息，学号、姓名、性别、年龄");

                     String[] split = input.readLine().split(" ");

                     Student student3 = new Student(Integer.parseInt(split[0]),

                             split[1], split[2].charAt(0),

                             Integer.parseInt(split[3]));

                     map.put(Integer.parseInt(split[0]), student3);

                     print(map);

                     break;

                 // 检索学生信息

                 case 2:

                     System.out.println("请输入要查询的学生的学号：");

                     Student search = map.get(Integer.parseInt(input.readLine()));

                     if (search != null) {

                         System.out.println("检索到学生的信息是：" + search.getId() + "\t"

                                 + search.getName() + "\t" + search.getSex()

                                 + "\t" + search.getAge());

                     }

                     break;

                     //删除学生信息

                 case 3:

                     System.out.println("请输入要删除的学生的学号：");

                     Student remove=map.remove(Integer.parseInt(input.readLine()));

                     if(remove!=null){

                         System.out.println("要删除的学生是：\n" + remove.getId()

                                 + "\t" + remove.getName() + "\t"

                                 + remove.getSex() + "\t" + remove.getAge());

                     }

                     break;

                 case 4:

                     System.exit(0);

                 default:

                     break;

                 }

             } catch (IOException e) {

                 e.printStackTrace();

             }

         }

     }

     static void print(HashMap<Integer, Student> map) {

         // 通过key来获取对应的值

         Set<Integer> keySet = map.keySet();

         System.out.println("学号\t姓名：\t性别：\t年龄：");

         for (Integer id : keySet) {

             System.out.println(id + "\t" + map.get(id).getName() + "\t"

                     + map.get(id).getSex() + "\t" + map.get(id).getAge());

         }

     }

 }