Repeat java basics (5): Object-oriented and java object-oriented

Repeat java basics (5): Object-oriented and java object-oriented

1. Encapsulation

Import java. util. date; public class Human {protected String name; protected BirthDay birthDay; protected String sex; public String getName () {return name;} public void setName (String name) {this. name = name;} public String getSex () {return sex;} public void setSex (String sex) {this. sex = sex;} public BirthDay getBirthDay () {return birthDay;} public void setBirthDay (BirthDay birthDay) {th Is. birthDay = birthDay;} public int getAge () {// encapsulation method if (birthDay! = Null) {Date nowDate = new Date (System. currentTimeMillis (); int year = nowDate. getYear () + 1900; int month = nowDate. getMonth () + 1; int day = nowDate. getDate (); int age = year-this. birthDay. getYear (); if (this. birthDay. getMonth ()> month) {return age-1;} else if (this. birthDay. getMonth () = month) {if (this. birthDay. getDay ()> = day) {return age-1 ;}} return age ;}return 0 ;}public String toString () {return "name:" + name + "sex: "+ sex +" age: "+ getAge ();} public String toString (Human human) {return this +" ";} public Human () {} public Human (String name, String sex) {super (); this. name = name; this. sex = sex;} public Human (String sex) {super (); this. sex = sex;} public Human (String name, String sex, int year, int month, int day) {super (); this. name = name; this. birthDay = new BirthDay (year, month, day); this. sex = sex ;}}

public class BirthDay {    private int year;        private int month;        private int 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 BirthDay(){            }    public BirthDay(int year, int month, int day) {        super();        this.year = year;        this.month = month;        this.day = day;    }    }

 

2. Inheritance

public class Woman extends Human{    public Woman(){        super("Woman");    }        public Woman(String name){        super(name,"Woman");    }        public String toString(){        return " I am Woman,"+super.toString();    }        public String toString(Woman woman){        return woman+"";    }}

public class Man extends Human{    public Man(){        super("Man");    }        public Man(String name){        super(name,"Man");    }        public String toString(){        return " I am Man,"+super.toString();    }        public String toString(Man man){        return man+"";    }    }

 

3. Polymorphism

public class TestOO {    public static void main(String[] args) {        Human man = new Man("man");        Human woman = new Woman("woman");        System.out.println(woman.toString(man));        System.out.println(man.toString(woman));    }}

Running result:

 I am Woman,name:woman sex:Woman age:0 I am Man,name:man sex:Man age:0