Java作业

每天都在摸鱼

已于 2022-04-16 21:02:18 修改

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文章标签： java

于 2022-04-09 17:40:24 首次发布

本文链接：https://blog.youkuaiyun.com/the_littlew/article/details/124064102

版权

这个博客展示了Java中HashSet的使用，包括创建、添加元素、获取并集、交集和差集。此外，还涉及了接口的实现，分别创建了中国和美国人的类，并实现了特定方法。另外，讲解了如何使用Calendar类处理日期，添加指定天数并格式化输出。最后，通过TreeSet展示了字典排序，并用ArrayList存储和展示了学生信息。

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HashSet

package Cai;
import java.util.Random;
import java.util.Scanner;
import java.util.HashSet;

public class Main {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        Random rdm=new Random();
        HashSet hs1=new HashSet();
        HashSet hs2=new HashSet();
        HashSet hs3=new HashSet();
       System.out.println("第一个集合");
       for(int i=0;i<5;i++)
       {
           hs1.add(rdm.nextInt(100));

       }
       System.out.println(hs1);
       System.out.println("第二个集合");
        for(int i=0;i<5;i++)
        {
            hs2.add(rdm.nextInt(100));

        }
        System.out.println(hs2);
        hs3.clear();
        hs3.addAll(hs1);
        hs3.addAll(hs2);
        System.out.println("并集"+hs3);
        hs3.clear();
        hs3.addAll(hs1);
        hs3.retainAll(hs2);
        System.out.println("交集"+hs3);
        hs3.clear();
        hs3.addAll(hs1);
        hs3.remove(hs2);
        System.out.println("差集"+hs3);




    }
}

接口

package Cai;

import java.util.Scanner;
interface People{
    void speakHello();
    void averageHeight();
    void averageWeight();

}
class ChinaPeople implements People{
    private int Height;
    private int Weight;
    public ChinaPeople()
    {}
    public void speakHello()
    {
        System.out.println("大家好我是中国人");
    }
    public ChinaPeople(int Height,int Weight)
    {
        this.Height=Height;
        this.Weight=Weight;
    }
    public void averageHeight()
    {
        System.out.println("平均升高是"+Height);
    }
    public void averageWeight()
    {
        System.out.println("平均升高是"+Weight);

    }
    public void chinaGongfu()
    {
        System.out.println("中国人都会功夫");
    }
}
 class AmericanPeople implements People {

    private int Height;
    private int Weight;
     public void speakHello()
     {
         System.out.println("大家好我是美国人");
     }
     public AmericanPeople()
     {}
     public AmericanPeople(int Height,int Weight)
     {
         this.Height=Height;
         this.Weight=Weight;
     }
     public void averageHeight()
     {
         System.out.println("平均升高是"+Height);
     }
     public void averageWeight()
     {
         System.out.println("平均升高是"+Weight);

     }
     public void americanBoxing()
     {
         System.out.println("美国人都会Boxing");

     }

 }
public class Math {
    public static void main(String[] args) {

        Scanner input=new Scanner(System.in);
        People a1=new ChinaPeople(165,50);
        a1.averageHeight();
        a1.averageWeight();
        a1.speakHello();
        ChinaPeople w=(ChinaPeople)a1;
        w.chinaGongfu();
        People a2=new AmericanPeople(166,60);
        a2.averageHeight();
        a2.averageWeight();
        a2.speakHello();
        AmericanPeople v=(AmericanPeople)a2;
        v.americanBoxing();






    }
}

200后的某一天Calender的使用

package Cai;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Scanner;

public class Math {
    public static void main(String[] args) {

        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.DAY_OF_YEAR, 200);//给当前日期加上200天
// 时间格式化
        SimpleDateFormat mFormat = new SimpleDateFormat("yyyy-MM-dd");
// 输出日期
        System.out.println("今天之后的第200天是：" + mFormat.format(calendar.getTime()));
// 从新格式化
        mFormat = new SimpleDateFormat("y");
// 显示年
        System.out.println(mFormat.format(calendar.getTime()));
// 从新格式化
        mFormat = new SimpleDateFormat("M");
// 显示几月
        System.out.println(mFormat.format(calendar.getTime()));
// 从新格式化
        mFormat = new SimpleDateFormat("d");//大写D和小写d不一样
// 显示那一天
        System.out.println(mFormat.format(calendar.getTime()));
        //显示星期几
        System.out.println(calendar.get(Calendar.DAY_OF_WEEK));






    }
}

字典排序 TreeSet

package Cai;
import java.util.Random;
import java.util.Scanner;
import java.util.HashSet;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        Set<String>ts=new TreeSet<String>();//存字符串
        String[]s=new String[]{"mike","tom","Lily","Jerry","Benny"};
        for(int i=0;i<s.length;i++)
        {
            ts.add(s[i]);

        }
        System.out.print(ts);




    }
}

ArrayList

package Cai;
import java.util.Random;
import java.util.Scanner;
import java.util.HashSet;
import java.util.ArrayList;
class Student{
     private String age;
     private String grade;
     private String name;
    public Student() {
    }
    public Student(String age,String grade,String name)
    {
        this.age=age;
        this.grade=grade;
        this.name=name;
    }

    public void show()
    {
        System.out.println(age+" "+grade+" "+name);
    }

}
public class Main {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        ArrayList<Student> array=new ArrayList<>();
        array.add(new Student("18","100","小王"));
        array.add(new Student("19","100","小杨"));
        array.add(new Student("20","59","小高"));
        array.add(new Student("21","56","小许"));
        array.add(new Student("22","25","小刘"));
        for (int i = 0; i < array.size(); i++) {
            System.out.println(array.get(i));
        }








    }
}

学生信息表

package Cai;
import java.awt.*;
import javax.swing.*;


public class Math {
    JTextField name;
    JTextField ID;
    JTextField number;
    JTextField result;
    JRadioButton rb1,rb2;
    JCheckBox cb1,cb2,cb3,cb4;
    JComboBox cb;
    JButton btn;
    JButton btn2;
    JLabel lblName,lblID,lblNumber,lblResult,lblHome,msg;
    ButtonGroup group=new ButtonGroup();
    String[] home={"中国","日本","挪威"};
    public static void main(String[] args) {
       JFrame f=new JFrame("学生信息");
       Math student=new Math();
       JPanel pane=student.init();
       f.getContentPane().add(pane);
       f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       f.setSize(400,200);
       f.setVisible(true);
    }
    public JPanel init()
    {
        JPanel p=new JPanel();
        JPanel p1=new JPanel(new GridLayout(2,1));
        JPanel p2=new JPanel(new GridLayout(4,1));
        p1.setBorder(BorderFactory.createTitledBorder("性别"));
        lblName=new JLabel("姓名");
        name=new JTextField(6);
        lblID=new JLabel("身份证");
        ID=new JTextField(12);
        lblHome=new JLabel("籍贯");
        btn=new JButton("提交");
        btn2=new JButton("取消");
        rb1=new JRadioButton("男性");
        rb2=new JRadioButton("女性");
        p1.add(rb1);
        p1.add(rb2);
        group.add(rb1);
        group.add(rb2);
        lblNumber=new JLabel("学号");
        number=new JTextField(9);
        lblResult=new JLabel("入学成绩");
        result=new JTextField(3);

        JComboBox cb=new JComboBox(home);
        p.add(lblName);
        p.add(name);
        p.add(lblID);
        p.add(ID);
        p.add(lblHome);
        p.add(cb);
        p.add(lblNumber);
        p.add(number);
        p.add(lblResult);
        p.add(result);

        p.add(rb1);
        p.add(rb2);
        p.add(btn);
        p.add(btn2);
        return p;
    }
}

接口

package Cai;
import java.util.Random;
import java.util.Scanner;


interface Area{
    double PI=3.14;

    double area();
}
interface SetColor{

    void setColor(String c);
}
interface Shape extends Area , SetColor{

    double volume();
}
class Cylinder implements Shape {
    private double radius;
    private double height;
    private String color;

    public Cylinder()
    {}
    public Cylinder(double radius , double height){
        this.radius=radius;
        this.height=height;
    }
    public double volume(){

        return PI*radius*radius*height;
    }
    public double area(){
        return PI*radius*radius;
    }
    public void setColor(String c){
        color=c;
    }
    public String toString()
    {
        double w=volume();
        double z=area();
        return "radius="+radius+"，"+"height="+height+"，"+"color is "+color+"，"+"volume="+w+"，"+"area="+z;
    }
}


public class Main {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        double a,b;
        a=input.nextDouble();
        b=input.nextDouble();
        String c=input.nextLine();


        String k=input.nextLine();
        Cylinder c1=new Cylinder(a,b);

        c1.setColor(k);
        System.out.print(c1.toString());













    }
}