01:
public class Encapsulation01
{
public static void main(String[] args)
{
Person person = new Person();
person.name = "Tom";
person.setAge(30);
person.setSalary(30000);
}
}
class Person
{
public String name;
private int age;
private double salary;
public void setSalary(double salary)
{
this.salary = salary;
}
public double getSalary()
{
return this.salary;
}
public void setAge(int age)
{
if (age >= 1 && age <= 123)
this.age = name;
else
{
System.out.println("Input Error");
this.age = 18;//给个默认age
}
}
public int getAge()
{
return this.age;
}
public void setName(String name)
{
if (name.length() >= 2 && name.length() <= 6)
this.name = name;
else
{
System.out.println("Input Error");
this.name = "wuming";
}
}
public String getName()
{
return this.name;
}
public String printElem()
{
return "name = "+name+" age = "+age+" salary = "+salary;
}
}
01:
public class Encapsulation01
{
public static void main(String[] args)
{
Person person = new Person();
person.name = "Tom";
person.setAge(30);
person.setSalary(30000);
}
}
class Person
{
public String name;
private int age;
private double salary;
public Person(){}
public Person(String name,int age,double salary){
//this.name = name;
// this.age = age;
// this.salary = salary;
setName(name);
setAge(age);
setSalary(salary);
}
public void setSalary(double salary)
{
this.salary = salary;
}
public double getSalary()
{
return this.salary;
}
public void setAge(int age)
{
if (age >= 1 && age <= 123)
this.age = name;
else
{
System.out.println("Input Error");
this.age = 18;//给个默认age
}
}
public int getAge()
{
return this.age;
}
public void setName(String name)
{
if (name.length() >= 2 && name.length() <= 6)
this.name = name;
else
{
System.out.println("Input Error");
this.name = "wuming";
}
}
public String getName()
{
return this.name;
}
public String printElem()
{
return "name = "+name+" age = "+age+" salary = "+salary;
}
}
小练习
package HelloDemo;
public class Account {
private String name;
private double balance;
private String password;
public Account(){}
public Account(String name, double balance, String password) {
this.setBalance(balance);
this.setName(name);
this.setPassword(password);
}
public String getName() {
return name;
}
public void setName(String name) {
if(name.length() >= 2 && name.length() <= 4)
this.name = name;
else
{
System.out.println("Input Error");
this.name = "wuming";
}
}
public double getBalance() {
return balance;
}
public void setBalance(double balance) {
if (balance > 20)
this.balance = balance;
else {
System.out.println("Input Error,balance = 0");
}
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
if (password.length()==6)
this.password = password;
else
{
System.out.println("Input Error password = 000000");
this.password = "000000";
}
}
public void showInfo()
{
//可以增加权限的校验
System.out.println("name = "+name+" balance = "+balance+" password = "+password);
}
}
//-------------------------------------------------------------------------------
package HelloDemo;
public class TestAccount {
public static void main(String[] args)
{
Account account = new Account();
account.setName("Tom");
account.setBalance(60);
account.setPassword("123456");
account.showInfo();
}
}
继承
01：
package JiCWorkDemo;
public class Pupil {
public String name;
public int age;
private double score;
public void setScore(double score) {
this.score = score;
}
public void testing()
{
System.out.println("pupil name= "+name);
}
public void showInfo()
{
System.out.println("name = "+name+" age = "+age+" score = "+score);
}
}
//===========================================
package JiCWorkDemo;
public class Graduate extends Pupil{
public void testing()
{
System.out.println("Graduate name= "+name);
}
}
//===========================================
package JiCWorkDemo;
public class WorkDemo {
public static void main(String[] args)
{
Pupil pupil = new Pupil();
pupil.name = "Tom";
pupil.age = 11;
pupil.testing();
pupil.setScore(50);
pupil.showInfo();
System.out.println("========");
Graduate graduate = new Graduate();
graduate.name = "Jack";
graduate.age = 23;
graduate.testing();
graduate.setScore(80);
graduate.showInfo();
}
}
继承的深入讨论/细节问题
01:
package JiCWorkDemo;
public class base {
public int n1 = 100;
protected int n2 = 200;
int n3 = 300;
private int n4 = 400;
public int getN4()
{
return n4;
}
public void callTest400()
{
test400();
}
public base()
{
System.out.println("base()......");
}
public void test100()
{
System.out.println("test100");
}
protected void test200()
{
System.out.println("test200");
}
void test300()
{
System.out.println("test300");
}
private void test400()
{
System.out.println("test400");
}
}
//==============================================
package JiCWorkDemo;
public class Son extends base{
public Son()
{
System.out.println("sub()...");
}
public void say0k()
{
System.out.println(n1+n2+n3);
test100();
test200();
test300();
//System.out.println(n4);//Error
//test400();//Error
System.out.println("n4 = "+getN4());
callTest400();
}
}
继承的本质分析
如果查找过程中，父类的age是private，而爷爷类的age是public，但还是会报错，因为找到父类的age是private以后就会报错，不会去找爷爷类的age
小练习结果如下:
我是A类
hahah我是B类的有参构造
我是c类的有参构造
我是c类的无参构造
01:
package ExerciseDemoWork;
public class Computer {
private String cpu;
private int memory;
private int disk;
public Computer(String cpu, int memory, int disk) {
this.cpu = cpu;
this.memory = memory;
this.disk = disk;
}
public String getDetails()
{
return "cpu = "+cpu+" memory = "+memory+" disk = "+disk;
}
public String getCpu() {
return cpu;
}
public void setCpu(String cpu) {
this.cpu = cpu;
}
public int getMemory() {
return memory;
}
public void setMemory(int memory) {
this.memory = memory;
}
public int getDisk() {
return disk;
}
public void setDisk(int disk) {
this.disk = disk;
}
}
//============================================================================
package ExerciseDemoWork;
public class PC extends Computer{
private String brand;
public PC(String cpu, int memory, int disk, String brand) {
super(cpu, memory, disk);
this.brand = brand;
}
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public void showInfo()
{
System.out.println("Pc = ");
System.out.println(getDetails()+"brand = "+brand);
}
}
//===========================================================================
package ExerciseDemoWork;
public class NotePad extends Computer{
private String color;
public NotePad(String cpu, int memory, int disk, String color) {
super(cpu, memory, disk);
this.color = color;
}
}
//=============================================================================
package ExerciseDemoWork;
public class Test {
public static void main(String[] args)
{
PC pc = new PC("intel", 16, 500, "IBM");
pc.showInfo();
}
}
super关键字
01:
package SuperWorkDemo;
public class B extends A{
public void hi() {
System.out.println(super.n1 + " " +super.n2 + " " + super.n3);
//System.out.println(super.n4);//Error
}
public void ok()
{
super.test100();
super.test200();
super.test300();
//super.test400();//Error
}
public B()
{
super("jack");
}
// public void hello()
// {
// //super();//error
// }
}
//==========================================================================
package SuperWorkDemo;
public class A {
public int n1 = 100;
protected int n2 = 200;
int n3 = 300;
private int n4 = 400;
public void test100(){};
protected void test200(){};
void test300(){};
private void test400(){};
public A(){}
public A(String str){}
}
细节
方法重写/覆盖
01:
package OverrideWorkDemo;
public class Animal {
public void cry()
{
System.out.println("动物叫唤");
}
}
//=============================================================
package OverrideWorkDemo;
public class Dog extends Animal{
public void cry()
{
System.out.println("Small dog crying");
}
}
//==================================================================
package OverrideWorkDemo;
public class Override01 {
public static void main(String[] args)
{
Dog dog = new Dog();
dog.cry();
}
}
注意事项和使用细节
小练习
01:
package PersonWorkDemo;
public class Person {
private String name;
private int age;
public String say()
{
return "name = "+name+" age = "+age;
}
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
//====================================
package PersonWorkDemo;
public class Student extends Person{
private int id;
private double score;
public Student(String name, int age, int id, double score) {
super(name, age);
this.id = id;
this.score = score;
}
public String say()
{
return super.say()+" id = "+id+" score = "+score;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public double getScore() {
return score;
}
public void setScore(double score) {
this.score = score;
}
}
//=================================================
package PersonWorkDemo;
public class OverrideExercise {
public static void main(String[] args)
{
Person jack = new Person("jack", 10);
System.out.println(jack.say());
Student smith = new Student("smith",20,123456,99.8);
System.out.println(smith.say());
}
// name = jack age = 10
// name = smith age = 20 id = 123456 score = 99.8
}
多态
01:
package Animal;
public class PolyObject {
public static void main(String[] args)
{
Animal animal = new Dog();
animal.cry();
animal = new Cat();
animal.cry();
}
}
//=====================================================================
package Animal;
public class Dog extends Animal{
@Override
public void cry() {
System.out.println("Dog cry cry......");
}
}
//===================================================================
package Animal;
public class Cat extends Animal{
@Override
public void cry() {
System.out.println("Cat cry cry....." );
}
}
//=================================================================
package Animal;
public class Animal {
public void cry()
{
System.out.println("Animal cry...");
}
}
多态注意事项和细节讨论
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01：
public class PolyDetail
{
public static void main(String[] args)
{
Animal animal = new Cat();
Object obj = new Cat();
System.out.println("ok~~");
}
}
- 可以调用父类中的所有成员(需遵守访问权限)，但是不能调用子类的特有的成员，因为在编译阶段，能调用哪些成员，是由编译类型来决定的
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多态的向下转型01:
Animal animal = new Cat(); Cat cat = (Cat)animal; cat.catchMouse();
02:
Animal animal = new Cat(); Dog dog = (Dog)animal;//Error
01:
package PolyDetailDemo;
public class PolyDetailedDemo {
public static void main(String[] args)
{
base base = new Sub();
System.out.println(base.count);//10
Sub sub = new Sub();
System.out.println(sub.count);//20
}
}
class base
{
int count = 10;
}
class Sub extends base{
int count = 20;
}
02:
public class PolyDetail03
{
public static void main(String[] args)
{
BB bb = new BB();
System.out.println(bb instanceof BB);//true
System.out.println(bb instanceof AA);//true
AA aa = new BB();
System.out.println(aa instanceof AA);//true
System.out.println(aa instanceof BB);//true
Object obj = new Object();
System.out.println(obj instanceof AA);//false
String str = "hello";
System.out.println(str instanceof Object);//true
}
}
class AA{}
class BB extends AA{}
小练习
01:
public class PolyExercise01
{
public static void main(String[] args)
{
double d = 13.4;//ok
long l = (long)d;//ok
System.out.println(l);//13
int in = 5;//ok
boolean b = (boolean)in;//error int -> boolean
Object obj = "Hello";//ok 向上转型
String objStr = (String)obj;//ok 向下转型
System.out.println(objStr);//hello
Object objPri = new Integer(5);//ok 向上转型
String str = (String)objPri;//Error 指向Integer的父类引用，转成String
Integer str1 = (Integer)objPri;//ok 向下转型
}
}
02：
package PolyDemoWork;
public class base {
int cnt = 10;
public void display()
{
System.out.println(this.cnt);
}
}
class Sub extends base{
int cnt = 20;
public void display()
{
System.out.println(this.cnt);
}
}
//==============================================================================
package PolyDemoWork;
public class PolyDemo {
public static void main(String[] args)
{
Sub s = new Sub();
System.out.println(s.cnt);//20
s.display();//20
base b = s;
System.out.println(b==s);//true
System.out.println(b.cnt);//10
b.display();//20
}
}
java的动态绑定机制
01:
package PolyDemoWork02;
public class A {
public int i = 10;
public int sum()
{
return get()+10;
}
public int sum1()
{
return i+10;
}
public int get()
{
return i;
}
}
//====================================================================================
package PolyDemoWork02;
public class B extends A{
public int i = 20;
public int sum()
{
return i+20;
}
public int get()
{
return i;
}
public int sum1()
{
return i+10;
}
}
//=========================================================================================
package PolyDemoWork02;
public class PolyMainDemo {
public static void main(String[] args) {
A a = new B();
System.out.println(a.sum());//40
System.out.println(a.sum1());//30
}
}
02:
package PolyDemoWork02;
public class B extends A{
public int i = 20;
// public int sum()
// {
// return i+20;
// }
public int get()
{
return i;
}
public int sum1()
{
return i+10;
}
}
//====================================================================
package PolyDemoWork02;
public class A {
public int i = 10;
public int sum()
{
return get()+10;
}
public int sum1()
{
return i+10;
}
public int get()
{
return i;
}
}
//==================================================================================
package PolyDemoWork02;
public class PolyMainDemo {
public static void main(String[] args) {
A a = new B();
System.out.println(a.sum());//30
System.out.println(a.sum1());//30
}
}
03:
package PolyDemoWork02;
public class B extends A{
public int i = 20;
// public int sum()
// {
// return i+20;
// }
public int get()
{
return i;
}
// public int sum1()
// {
// return i+10;
// }
}
//====================================================================================
package PolyDemoWork02;
public class A {
public int i = 10;
public int sum()
{
return get()+10;
}
public int sum1()
{
return i+10;
}
public int get()
{
return i;
}
}
//==============================================================================
package PolyDemoWork02;
public class PolyMainDemo {
public static void main(String[] args) {
A a = new B();
System.out.println(a.sum());//30
System.out.println(a.sum1());//20
}
}
多态的应用
多态数组
01：
package Person;
public class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String say()
{
return name+" "+age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
//=========================================================
package Person;
public class Student extends Person{
private double score;
public Student(String name, int age, double socre) {
super(name, age);
this.score = socre;
}
public double getSocre() {
return score;
}
public void setSocre(double socre) {
this.score = socre;
}
@Override
public String say() {
return super.say()+" score = "+score;
}
}
//==========================================================================
package Person;
public class Teacher extends Person{
private double sal;
public Teacher(String name, int age, double sal) {
super(name, age);
this.sal = sal;
}
public double getSal() {
return sal;
}
public void setSal(double sal) {
this.sal = sal;
}
@Override
public String say() {
return super.say()+" sal = "+sal;
}
}
//==========================================================================
package Person;
public class PolyArray {
public static void main(String[] args)
{
Person[] persons = new Person[3];
persons[0] = new Person("Tom",20);
persons[1] = new Student("Jack",30,100);
persons[2] = new Teacher("Bob",33,4500);
for (int i = 0;i
02：
package Person;
public class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String say()
{
return name+" "+age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
//=================================================================================
package Person;
public class Student extends Person{
private double score;
public Student(String name, int age, double socre) {
super(name, age);
this.score = socre;
}
public double getSocre() {
return score;
}
public void setSocre(double socre) {
this.score = socre;
}
@Override
public String say() {
return super.say()+" score = "+score;
}
public void study()
{
System.out.println("student = "+getName());
}
}
//=========================================================================
package Person;
public class Teacher extends Person{
private double sal;
public Teacher(String name, int age, double sal) {
super(name, age);
this.sal = sal;
}
public double getSal() {
return sal;
}
public void setSal(double sal) {
this.sal = sal;
}
@Override
public String say() {
return super.say()+" sal = "+sal;
}
public void teach()
{
System.out.println("teacher = "+getName());
}
}
//=============================================================================
package Person;
public class PolyArray {
public static void main(String[] args)
{
Person[] persons = new Person[3];
persons[0] = new Person("Tom",20);
persons[1] = new Student("Jack",30,100);
persons[2] = new Teacher("Bob",33,4500);
for (int i = 0;i
多态参数
01:
package TestPolyDemo;
public class Employee {
private String name;
private double salary;
public Employee(String name, double salary) {
this.name = name;
this.salary = salary;
}
public double getAnnual()
{
return 12*salary;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
}
//=====================================================================
package TestPolyDemo;
public class Worker extends Employee{
public Worker(String name, double salary) {
super(name, salary);
}
public void work()
{
System.out.println("worker = "+getName()+"working!!!");
}
@Override
public double getAnnual() {
return super.getAnnual();
}
}
//==============================================================================
package TestPolyDemo;
public class Manager extends Employee{
private double bonus;
public Manager(String name, double salary, double bonus) {
super(name, salary);
this.bonus = bonus;
}
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
public void manage()
{
System.out.println("manager" + getName()+"is managing");
}
@Override
public double getAnnual() {
return super.getAnnual()+bonus;
}
}
//======================================================================
package TestPolyDemo;
public class TestWorkDemo {
public static void main(String[] args)
{
Worker tom = new Worker("tom",2500);
Manager milan = new Manager("milan", 5000, 200000);
TestWorkDemo testWorkDemo = new TestWorkDemo();
testWorkDemo.showEmpAnnual(tom);
testWorkDemo.showEmpAnnual(milan);
testWorkDemo.testWork(tom);
testWorkDemo.testWork(milan);
}
public void showEmpAnnual(Employee e)
{
System.out.println(e.getAnnual());
}
public void testWork(Employee e)
{
if (e instanceof Worker)
{
((Worker) e).work();
}
else if (e instanceof Manager)
{
((Manager) e).manage();
}
else
{
System.out.println("no");
}
}
}
Object类
==运算符和equals
01:
package ObjectDemo;
public class Equals01 {
public static void main(String[] args)
{
A a = new A();
A b = a;
A c = b;
System.out.println(a==c);//true
System.out.println(b==c);//true
B obj = a;
System.out.println(obj==c);//true 地址还是一样
"hello".equals("abc");
//String equals
// public boolean equals(Object anObject) {
// if (this == anObject) {
// return true;
// }
// if (anObject instanceof String) {
// String aString = (String)anObject;
// if (!COMPACT_STRINGS || this.coder == aString.coder) {
// return StringLatin1.equals(value, aString.value);
// }
// }
// return false;
// }
//Object equals
// public boolean equals(Object obj) {
// return (this == obj);
// }
Integer integer1 = new Integer(1000);
Integer integer2 = new Integer(1000);
System.out.println(integer1 == integer2);//false
System.out.println(integer1.equals(integer2));//true
String str1 = new String("hspedu");
String str2 = new String("hspedu");
System.out.println(str1==str2);//false
System.out.println(str1.equals(str2));//true
// Integer equals
// public boolean equals(Object obj) {
// if (obj instanceof Integer) {
// return value == ((Integer)obj).intValue();
// }
// return false;
// }
}
}
class B{}
class A extends B
{
}
如何重写equals方法
01:
package EqualsExercise01;
public class EqualsExercise01 {
public static void main(String[] args)
{
Person person1 = new Person("jack", 10, '男');
Person person2 = new Person("jack", 10, '男');
System.out.println(person1.equals(person2));
}
}
class Person
{
private String name;
private int age;
private char gender;
public boolean equals(Object obj)
{
if (this==obj)
{
return true;
}
if (obj instanceof Person)
{
Person p = (Person)obj;
return this.name.equals(p.name) && this.age== p.age && this.gender ==p.gender;
}
return false;
}
public Person(String name, int age, char gender) {
this.name = name;
this.age = age;
this.gender = gender;
}
}
小练习
01:
02:
public class WorkDemo {
public static void main(String[] args) {
int it = 65;
float fl = 65.0f;
System.out.println("65和65.0f是否相等?"+(it==fl));//true
char ch1 = 'A';
char ch2 = 12;
System.out.println("65和'A'是否相等？"+(it==ch1));//true
System.out.println("12和ch2是否相等?"+(12==ch2));//true
String str1 = new String("hello");
String str2 = new String("hello");
System.out.println((str1==str2));//false
System.out.println(str1.equals(str2));//true
}
}
hashCode方法
toString方法
01：
package ObjectWorkDemo;
public class TestDemo02 {
public static void main(String[] args) {
// Object的toString()源码
// public String toString() {
// return getClass().getName() + "@" + Integer.toHexString(hashCode());
// }
Monster monster = new Monster("Tom", "climb", 1000);
System.out.println(monster.toString()+" "+monster.hashCode());
//ObjectWorkDemo.Monster@776ec8df 2003749087
//Monster{name='Tom', job='climb', sal=1000.0} 1072408673
System.out.println(monster);
//Monster{name='Tom', job='climb', sal=1000.0}
}
}
class Monster
{
private String name;
private String job;
private double sal;
public Monster(String name, String job, double sal) {
this.name = name;
this.job = job;
this.sal = sal;
}
@Override
public String toString() {
return "Monster{" +
"name='" + name + ''' +
", job='" + job + ''' +
", sal=" + sal +
'}';
}
}
finalize方法
01:
package FinalizeDemo;
public class FinalizeDemo {
public static void main(String[] args)
{
Car Bwm = new Car("Baoma");
Bwm = null;
System.gc();
}
}
class Car
{
private String name;
public Car(String name) {
this.name = name;
}
@Override
protected void finalize() throws Throwable {
System.out.println("Car destory!");
}
}
大练习
01：
package HomeWorkDemo;
public class HomeWorkDemo01 {
public static void main(String[] args)
{
Person[] persons = new Person[3];
persons[0] = new Person("Tom",35,"JavaEE工程师");
persons[1] = new Person("jack",18,"C++工程师");
persons[2] = new Person("mike",89,"Teacher");
for (int i = 0;i
02:
03:
package HomeWorkDemo01;
public class Teacher
{
private String name;
private int age;
private String post;
private double salary;
private double grade;
public Teacher(String name, int age, String post, double salary, double grade) {
this.name = name;
this.age = age;
this.post = post;
this.salary = salary;
this.grade = grade;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getPost() {
return post;
}
public void setPost(String post) {
this.post = post;
}
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public double getGrade() {
return grade;
}
public void setGrade(double grade) {
this.grade = grade;
}
public void introduce()
{
System.out.println(toString());
}
@Override
public String toString() {
return "Teacher{" +
"name='" + name + ''' +
", age=" + age +
", post='" + post + ''' +
", salary=" + salary +
", grade=" + grade +
'}';
}
}
//=================================================
package HomeWorkDemo01;
public class Professor extends Teacher{
public Professor(String name, int age, String post, double salary, double grade) {
super(name, age, post, salary, grade);
}
@Override
public void introduce() {
System.out.println("this is professor");
super.introduce();
}
}
//===================================================
package HomeWorkDemo01;
public class HomeWork03 {
public static void main(String[] args)
{
Professor professor = new Professor("贾宝玉", 30, "高级职称", 30000, 1.3);
professor.introduce();
}
}
04:
package HomeWork04;
public class Employee {
private String name;
private double daySal;
private int workDays;
private double grade;
public void printSal()
{
System.out.println(name+" Sal = "+daySal*workDays*grade);
}
public Employee(String name, double daySal, int workDays, double grade) {
this.name = name;
this.daySal = daySal;
this.workDays = workDays;
this.grade = grade;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getDaySal() {
return daySal;
}
public void setDaySal(double daySal) {
this.daySal = daySal;
}
public int getWorkDays() {
return workDays;
}
public void setWorkDays(int workDays) {
this.workDays = workDays;
}
public double getGrade() {
return grade;
}
public void setGrade(double grade) {
this.grade = grade;
}
}
//==================================================
package HomeWork04;
public class Manager extends Employee{
private double bonus;
public Manager(String name, double daySal, int workDays, double grade) {
super(name, daySal, workDays, grade);
}
@Override
public void printSal() {
System.out.println("name"+getName()+" Sal = "+(bonus+getDaySal()*getWorkDays()*getGrade()));
}
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
}
//==================================================
package HomeWork04;
public class Worker extends Employee{
public Worker(String name, double daySal, int workDays, double grade) {
super(name, daySal, workDays, grade);
}
@Override
public void printSal() {
super.printSal();
}
}
//==================================================
package HomeWork04;
public class HomeWork04 {
public static void main(String[] args)
{
Manager manage= new Manager("刘备", 100, 20, 1.2);
manage.setBonus(3000);
manage.printSal();
Worker worker = new Worker("关羽",50,10,1.0);
worker.printSal();
}
}
05:
package HomeWork05;
public class Worker extends Employee{
public Worker(String name, double sal) {
super(name, sal);
}
@Override
public void printSal() {
System.out.println("Worker = ");
super.printSal();
}
}
//==============================================
package HomeWork05;
public class Employee {
private String name;
private double sal;
private int salMonth = 12;
public Employee(String name, double sal) {
this.name = name;
this.sal = sal;
}
public void printSal()
{
System.out.println(name+" Sal = "+(sal*salMonth));
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getSal() {
return sal;
}
public void setSal(double sal) {
this.sal = sal;
}
public int getSalMonth() {
return salMonth;
}
public void setSalMonth(int salMonth) {
this.salMonth = salMonth;
}
}
//============================================
package HomeWork05;
public class Peasant extends Employee{
public Peasant(String name, double sal) {
super(name, sal);
}
@Override
public void printSal() {
System.out.println("Peasant = ");
super.printSal();
}
}
//============================================
package HomeWork05;
public class Teacher extends Employee{
private int classDays;
private double classSal;
@Override
public void printSal() {
System.out.println("name = "+getName()+" Sal = "+(getSal()*getSalMonth()+classDays * classSal));
}
public Teacher(String name, double sal) {
super(name, sal);
}
public int getClassDays() {
return classDays;
}
public void setClassDays(int classDays) {
this.classDays = classDays;
}
public double getClassSal() {
return classSal;
}
public void setClassSal(double classSal) {
this.classSal = classSal;
}
}
//===============================================
package HomeWork05;
public class Scientist extends Employee{
private double bonus;
public Scientist(String name, double sal) {
super(name, sal);
}
@Override
public void printSal() {
System.out.println("Scientist = "+getName()+" Sal = "+getSal()*getSalMonth()+bonus);
}
public double getBonus() {
return bonus;
}
public void setBonus(double bonus) {
this.bonus = bonus;
}
}
//============================================
package HomeWork05;
public class HomeWork05 {
public static void main(String[] args)
{
Worker jack = new Worker("jack",1000);
jack.printSal();
Peasant smith = new Peasant("smith", 20000);
smith.printSal();
Teacher teacher = new Teacher("顺平", 2000);
teacher.setClassDays(360);
teacher.setClassSal(5000);
teacher.printSal();
Scientist scientist = new Scientist("钟南山", 20000);
scientist.setBonus(2000000);
scientist.printSal();
}
}
06:
07:
package HomeWork07;
public class Test {
String name = "Rose";
Test()
{
System.out.println("Test");
}
Test(String name)
{
this.name = name;
}
}
class Demo extends Test{
String name = "jack";
Demo()
{
super();
System.out.println("Demo");
}
Demo(String s)
{
super(s);
}
public void test()
{
System.out.println(super.name);
System.out.println(this.name);
}
public static void main(String [] args)
{
new Demo().test();
new Demo("join").test();
}
}
// Test
// Demo
// Rose
// jack
// join
// jack
08:
查看JDK源码
