Java学习

  • 引语
  • 案例
  • 实现过程
  • 思路
  • 代码
  • 结果


引语

记录学习路程,抛砖引玉。如有更好的算法或者出现错误,欢迎指点。

案例

  1. 记录学生所在宿舍的楼号、房编号
  2. 记录学生的名称、学号、性别、年龄以及住宿时间
  3. 注意:学号、年龄以及住宿时间不可为负,年龄合理区间设为10~100

实现过程

思路

  1. 首先定义两个类:RoomStudent
  2. 然后分别定义各自的属性。Room的属性有楼栋名称、宿舍房号、住宿时间;Student的属性有名称、学号、性别、年龄
  3. 接着处理有关的注意事项,完善属性功能
  4. 最后定义个test类进行功能测试,完成案例实现

代码

java获取班级姓张的人数 java班级姓名学号_数组

Room:

package roomate;

public class Room {
    // 成员属性:宿舍名称、宿舍编号、住宿时间、学生信息、学生个数
    private String roomName;      //private设置属性在此类私有,提高安全合法性
    private String roomNo;
    private int roomLife;
    private Student[] myStudents;
    private int studentNum;

    // 无参构造方法
    public Room() {

    }

    // 带参构造,带参构造,实现对全部属性的赋值
    public Room(String roomName, String roomNo, int roomLife) {
        // this.roomName=roomName;安全起见,使用以下的方法赋值
        this.setRoomName(roomName);//楼栋名称
        this.setRoomNo(roomNo);//宿舍编号
        this.setRoomLife(roomLife);//住宿年期
    }

    public void setRoomName(String roomName) {
        this.roomName = roomName;
    }

    public String getRoomName() {
        return this.roomName;
    }

    public String getRoomNo() {
        return roomNo;
    }

    public void setRoomNo(String roomNo) {
        this.roomNo = roomNo;
    }

    public int getRoomLife() {
        return roomLife;
    }

    // 设置年限,限制必须>0
    public void setRoomLife(int roomLife) {
        if (roomLife <= 0)
//			system.out.println("error!");
            return;
        this.roomLife = roomLife;
    }

    /**
     * 获取宿舍学生信息 如果保存学生信息的数组未被初始化,则,先初始化长度200
     * @return 保存学生信息的数组
     */
    public Student[] getMyStudents() {
        if(this.myStudents==null)
            this.myStudents=new Student[200];
        return myStudents;
    }

    public void setMyStudents(Student[] myStudents) {
        this.myStudents = myStudents;
    }

    public int getStudentNum() {
        return studentNum;
    }

    public void setStudentNum(int studentNum) {
        this.studentNum = studentNum;
    }

    /**
     * 宿舍介绍的方法
     * @return 介绍宿舍的相关信息,包括楼栋名称、宿舍编号、住宿年期
     */
    public String info() {
        String str = "宿舍信息如下:\n宿舍名称:" + this.getRoomName() + "\n宿舍编号:" + this.getRoomNo() + "\n住宿年限:"
                + this.getRoomLife() + "年";
        return str;
    }

    public void addStudent(Student stu){
        /*
         * 1、将学生保存到数组中
         * 2、将学生个数保存到studentNum
         * */
        //1、将学生保存到数组中
        for(int i=0;i<this.getMyStudents().length;i++){
            if(this.getMyStudents()[i]==null){
                stu.setStudentRoom(this);
                this.getMyStudents()[i]=stu;
                //2、将学生个数保存到studentNum
                this.studentNum=i+1;
                return;
            }
        }
    }
}

Student:

package roomate;

import roomate.Room;

public class Student {
    // 成员属性:学号、姓名、性别、年龄、宿舍
    private String studentNo;
    private String studentName;
    private String studentSex;
    private int studentAge;
    private Room studentRoom;

    // 无参构造方法
    public Student() {

    }
    //多参构造方法,实现对学号、姓名、性别、年龄的赋值
    public Student(String studentNo, String studentName, String studentSex, int studentAge) {
        this.setStudentNo(studentNo);
        this.setStudentName(studentName);
        this.setStudentSex(studentSex);
        this.setStudentAge(studentAge);
    }
    // 多参构造方法,实现对全部属性的赋值
/*	public Student(String studentNo, String studentName, String studentSex, int studentAge,Room studentRoom) {
		this.setStudentNo(studentNo);
		this.setStudentName(studentName);
		this.setStudentSex(studentSex);
		this.setStudentAge(studentAge);
		// this.studentAge=studentAge;
		this.setStudentRoom(studentRoom);
	}
*/
    public String getStudentNo() {
        return studentNo;
    }
    public void setStudentNo(String studentNo) {
        this.studentNo = studentNo;
    }



    public String getStudentName() {
        return studentName;
    }
    public void setStudentName(String studentName) {
        this.studentName = studentName;
    }



    public String getStudentSex() {
        return studentSex;
    }
    public void setStudentSex(String studentSex) {
        // 限制性别只能是“男”或者“女”,反之,强制赋值为“男”
        this.studentSex = studentSex;
    }



    public int getStudentAge() {
        return studentAge;
    }
    /**
     * 给年龄赋值,限定必须在10--100之间,反之赋值为0
     *
     * @param studentAge
     *            传入的年龄
     */
    public void setStudentAge(int studentAge) {
        if (studentAge < 10 || studentAge > 100)
            this.studentAge = 0;      //年龄超100及低10判定为出错,使其值为0
        else
            this.studentAge = studentAge;
    }



    /**
     * 获取宿舍对象,如果没有实例化,先实例化后再返回
     * @return 宿舍对象信息
     */
    public Room getStudentRoom() {
        if(this.studentRoom==null)
            this.studentRoom=new Room();
        return studentRoom;
    }
    public void setStudentRoom(Room studentRoom) {
        this.studentRoom = studentRoom;
    }




    /**
     * 学生自我介绍的方法
     *
     * @return 自我介绍的信息,包括姓名、学号、性别、年龄
     */
    public String introduction() {
        String str = "学生信息如下:\n姓名:" + this.getStudentName() + "\n学号:" + this.getStudentNo() + "\n性别:"
                + this.getStudentSex() + "\n年龄:" + this.getStudentAge()+ "\n所在宿舍名称:" + this.getStudentRoom().getRoomName() + "\n住宿年限:"
                + this.getStudentRoom().getRoomLife();
        return str;
    }

    
    public String introduction(String roomName,String roomNo, int roomLife) {
        String str = "学生信息如下:\n姓名:" + this.getStudentName() + "\n学号:" + this.getStudentNo() + "\n性别:"
                + this.getStudentSex() + "\n年龄:" + this.getStudentAge() + "\n所在宿舍名称:" + roomName + "\n宿舍编号:"+roomNo + "\n住宿年限:"
                + roomLife;
        return str;
    }

    /**
     * 学生自我介绍的方法
     * @param myRoom 所在宿舍的对象
     * @return自我介绍的信息,包括姓名、学号、性别、年龄、所在宿舍名称、住宿年限
     */
    public String introduction(Room myRoom){
        String str = "学生信息如下:\n姓名:" + this.getStudentName() + "\n学号:" + this.getStudentNo() + "\n性别:"
                + this.getStudentSex() + "\n年龄:" + this.getStudentAge() + "\n所在宿舍名称:" + myRoom.getRoomName() + "\n住宿年限:"
                + myRoom.getRoomLife()+"\n宿舍编号:"+myRoom.getRoomNo();
        return str;
    }
}

StudentTest:

package test;
import roomate.Room;
import roomate.Student;

public class StudentTest {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        //测试Subject
        Room sub1=new Room("K","J0001",2);//宿舍类
        System.out.println(sub1.info());
        System.out.println("================================");
        //测试Student,学生类
        Student stu1=new Student("S01","张三","男",200);   //刻意让年龄不满足10~100区间
        System.out.println(stu1.introduction("K","J0003",4));
        System.out.println("================================");
        Student stu2=new Student("S02","李四","女",17);
        System.out.println(stu2.introduction("L", "J0002",3));
        System.out.println("================================");
        Student stu3=new Student("S03","王五","男",18);
        System.out.println(stu3.introduction(sub1));
        System.out.println("================================");
        //统计住宿学生人数
        sub1.addStudent(stu1);
        sub1.addStudent(stu2);
        sub1.addStudent(stu3);
        System.out.println("宿舍中已有"+sub1.getStudentNum()+"学生正在住宿");
    }
}

结果

宿舍信息如下:
宿舍名称:K
宿舍编号:J0001
住宿年限:4年
================================
学生信息如下:
姓名:张三
学号:S01
性别:男
年龄:0        //因为年龄200不符合条件所以输出显示值为0
所在宿舍名称:K
宿舍编号:J0003
住宿年限:4
================================
学生信息如下:
姓名:李四
学号:S02
性别:女
年龄:17
所在宿舍名称:L
宿舍编号:J0002
住宿年限:3
================================
学生信息如下:
姓名:王五
学号:S03
性别:男
年龄:18
所在宿舍名称:K
住宿年限:2
宿舍编号:J0001
================================
宿舍中已有3学生正在住宿

Process finished with exit code 0