java入门基础

package TEXT.LIAN;

public class mianText {
    
    public static void main(String[] args) {
        String[] PP=new String[100];
        Main.main(PP);
    }
}
class Main{
    public static void main(String[] args) {
        for (int i=0;i
            args[i] ="args_"+i;
            System.out.println(args[i]);
        }
    }
}

package text2.test1;



public class BlockTest {
    public static void main(String[] args) {
        String desc = Person.desc;
        System.out.println(desc);

        //造对象
        Person person = new Person();
        Person p2 = new Person();

        System.out.println(person.age);

        Person.info();

    }
}

class Person {
    String name;
    int age;
    static String desc = "我是一个人";

    //空参构造器
    public Person() {

    }

    //待参构造器
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    //代码块
    static {
        System.out.println("hello,static block");
        desc="爱学校的";
    }

    //非静态代码块
    {
        System.out.println("hello block");
        age=11;
    }

    //方法
    public void eat() {
        System.out.println("吃饭");
    }

    //  toString方法
    @Override
    public String toString() {
        return "Person[name=" + name + ",age=" + age + "]";
    }

    public static void info(){
        System.out.println("我是个快乐的人！");
    }
}

package text2.test1;

public class LeafTest {
    public static void main(String[] args) {
        new Leaf();
        //静态代码块只执行一次
//        new Leaf();
    }
}


class Root {
    static {
        System.out.println("Root的静态初始化块");
    }

    {
        System.out.println("Root的普通初始化");
    }

    public Root() {
        super();
        System.out.println("Root的无参数构造器");
    }
}

class Mid extends Root {
    static {
        System.out.println("Mid的静态初始化块");
    }

    {
        System.out.println("Mid的普通初始化块");
    }

    public Mid() {
        System.out.println("Mid的无参数构造器");
    }

    public Mid(String msg) {
//通过this调用同一类中重载的构造器
        this();
        System.out.println("Mid的带参数构造器，其参数值：" + msg);
    }
}

class Leaf extends Mid {
    static {
        System.out.println("Leaf的静态初始化块");
    }

    {
        System.out.println("Leaf的普通初始化块");
    }

    public Leaf() {
        super("尚硅谷");
        System.out.println("Leaf的带参构造器");
    }
}

1.静态代码和非静态代码块的排序执行

package text2.test1;

public class Son extends Father {
    static {
        System.out.println("4444444444444");
    }

    {
        System.out.println("5555555555555");
    }

    public Son() {
        System.out.println("6666666666666");
    }

    public static  void main(String[] args){
          System.out.println("7777777777777");
          System.out.println("*************");
          new Son();
    }

}

class Father {
    static {
        System.out.println("11111111111111");
    }

    {
        System.out.println("22222222222222");
    }
}

package text3.abstract1;


public class AbstractTest {
    public static void main(String[] args) {
    
        //一旦Person类抽象了，就不可实例化

    }
}


//抽象类
abstract class Creature {
    //抽象方法
    public abstract void breath();
}

//抽象类的继承
abstract class Person extends Creature {
    //抽象方法
    public abstract void eaopop();

    //属性
    String name;
    int age;

    //构造器
    public Person() {

    }

    //带参构造器
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }


    //方法
    public void eat() {
        System.out.println("人吃饭");
    }

    //方法
    public void waIk() {
        System.out.println("人走路");
    }
}


//抽象类的继承，里面重写了抽象方法
//Studer类可以实例化对象
class Studet extends Person {

    //带参构造器
    public Studet(String name, int age) {
        super(name, age);
    }

    //无参构造器
    public Studet() {

    }

    //重写父类抽象类的方法
    public void eaopop() {

    }
    //重写父类抽象类的方法
    public void breath() {

    }
}


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

        method(new Studet());//匿名对象

        Worker worker = new Worker();
        method1(worker);//非匿名的类非匿名的对象

        method1(new Worker());//非匿名的类匿名对象
        System.out.println("***********************");
        //创建了一匿名子类的对象：p
       

        //创建实例进行赋值
        Person opp= new Person() {
            @Override
            public void eaopop() {
                System.out.println("吃你");
            }

            @Override
            public void breath() {
                System.out.println("吃你");
            }
        };
        method1(opp);
    }

    public static void method1(Person p) {
        p.breath();
        p.eaopop();
    }

    public static void method(Studet s) {

    }
}

class Worker extends Person {
    public void breath() {

    }

    public void eaopop() {

    }

}

主方法

package case1;



import java.util.Calendar;
import java.util.Scanner;

public class PayrollSystem {
    public static void main(String[] args) {
//方式一：
//		Scanner scanner = new Scanner(System.in);
//		System.out.println("请输入当月的月份：");
//		int month = scanner.nextInt();

        //方式二：
        Calendar calendar = Calendar.getInstance();
        int month = calendar.get(Calendar.MONTH);//获取当前的月份
//		System.out.println(month);//一月份：0

        Employee[] emps = new Employee[3];

        emps[0] = new SalariedEmployee("马森", 1002,new MyDate(1992, 5, 28),10000);
        emps[1] = new HourlyEmployee("潘雨生", 2001, new MyDate(1991, 1, 6),60,240);
        emps[2] = new SalariedEmployee("阿萨德", 2007, new MyDate(1991, 1, 6),2940);



        for(int i = 0;i < emps.length;i++){
            System.out.println(emps[i]);
            double salary = emps[i].earnings();
            System.out.println("月工资为：" + salary);

            if((month+1) == emps[i].getBirthday().getMonth()){
                System.out.println("生日快乐！奖励100元");
            }
        }

    }
}

父类

package case1;



 abstract public class Employee {
    private String name;
    private int number;
    private MyDate birthday;

     public Employee(String name, int number, MyDate birthday) {
//         super();
         this.name = name;
         this.number = number;
         this.birthday = birthday;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public int getNumber() {
         return number;
     }

     public void setNumber(int number) {
         this.number = number;
     }

     public MyDate getBirthday() {
         return birthday;
     }

     public void setBirthday(MyDate birthday) {
         this.birthday = birthday;
     }

     public abstract double earnings();


     @Override
     public String toString() {
         return "Employee[name="+name+",number="+number+",birthday="+birthday.toDateString();
     }
 }

属性类

package case1;


public class MyDate {
    private int year;
    private int month;
    private int day;

    public MyDate(int year, int month, int day) {
//        super();
        this.year = year;
        this.month = month;
        this.day = day;
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        this.year = year;
    }

    public int getMonth() {
        return month;
    }

    public void setMonth(int month) {
        this.month = month;
    }

    public int getDay() {
        return day;
    }

    public void setDay(int day) {
        this.day = day;
    }

    public String toDateString() {
        return year+"年"+month+"月"+day+"日";
    }


}

子类

package case1;


public class SalariedEmployee extends Employee {

    private double monthlySalary;//月工资

    public SalariedEmployee(String name, int number, MyDate birthday) {
        super(name, number, birthday);
    }

    public SalariedEmployee(String name, int number, MyDate birthday, double monthlySalary) {
        super(name, number, birthday);
        this.monthlySalary = monthlySalary;
    }

    public double getMonthlySalary() {
        return monthlySalary;
    }

    public void setMonthlySalary(double monthlySalary) {
        this.monthlySalary = monthlySalary;
    }

    @Override
    public double earnings() {
        return monthlySalary;
    }

    public String toString() {
        return "SalariedEmployee[" + super.toString() + "]";
    }


}

子类

package case1;


public class HourlyEmployee extends Employee {
    private int wage;//每小时的工资
    private int hour;//月工作的小时数

    public HourlyEmployee(String name, int number, MyDate birthday) {
        super(name, number, birthday);
    }

    public HourlyEmployee(String name, int number, MyDate birthday, int wage, int hour) {
        super(name, number, birthday);
        this.wage = wage;
        this.hour = hour;
    }

    public int getWage() {
        return wage;
    }

    public void setWage(int wage) {
        this.wage = wage;
    }

    public int getHour() {
        return hour;
    }

    public void setHour(int hour) {
        this.hour = hour;
    }

    @Override
    public double earnings() {
        return wage * hour;
    }

    public String toString() {
        return "HourlyEmployee[" + super.toString() + "]";
    }
}