1、Person类
package com.yfs.javase;
public class Person {
String name;//每个对象上分配 与对象绑定
int age;
char sex;
boolean married;
static String country = "中国";//静态属性 与类绑定 所有对象共享
public static void baseInfo () {//静态方法 与类绑定 所有对象共享
System.out.println("舌尖上的中国...");
//method() ;//静态方法不能调用非静态方法
//String n = name;//静态方法不能访问非静态属性
String n = country;
}
public void test () {//非静态方法
System.out.println("call test() ....");
name = "Tom";//访问非静态属性
String s = country;//访问静态属性
System.out.println("s = " + s);
//调用静态方法
baseInfo();
}
public void method () {
System.out.println("method() ....");
}
}
2.Person测试1
package com.yfs.javase;
public class PersonTest {
public static void main(String[] args) {
Person p1 = null;
p1 = new Person();
p1.name = "张三";
Person p2 = new Person();
p2.name = "李四";
System.out.println("p1.name " + p1.name);
System.out.println("p2.name " + p2.name);
System.out.println("=========================");
p1.name = "王五";
System.out.println("p1.name " + p1.name);
System.out.println("p2.name " + p2.name);
//静态属性通过类名访问
System.out.println("Person.country " + Person.country);
p1.country = "日本";
System.out.println("Person.country " + Person.country);
System.out.println("p2.country " + p2.country);
// Person.baseInfo();//静态属性 方法通过类访问
// p1.baseInfo();
// p2.baseInfo();
p1.test();
}
}
3.测试Person2
package com.yfs.javase;
public class PersonTest1 {
public static void main(String[] args) {
Person p1 = null;//类加载
System.out.println(Person.country);
Person.baseInfo();
//p1.name = "张三";
}
}
4.Person 类2(代码块、静态代码块）
package com.yfs.javase;
public class Person {
String name;// 每个对象上分配 与对象绑定
int age;
char sex;
boolean married;
// 代码块 执行时机 创建对象时执行
{
System.out.println("这是代码块的内容");
}
// 静态代码块 与类绑定 只执行一次
static {
System.out.println("这是静态代码块内容....");
}
public Person() {
System.out.println("创建Person对象");
}
public Person(String name) {
System.out.println("Person(name) ....");
this.name = name;
}
public Person(String name, int age, char sex, boolean married) {
// this(name);//构造方法调用
this.name = name;
this.age = age;
this.sex = sex;
this.married = married;
System.out.println("四个参数的构造方法...");
}
static String country = "中国";// 静态属性 与类绑定 所有对象共享
public static void baseInfo() {// 静态方法 与类绑定 所有对象共享
System.out.println("舌尖上的中国...");
String n = country;
}
public void test() {// 非静态方法
System.out.println("call test() ....");
name = "Tom";// 访问非静态属性
String s = country;// 访问静态属性
System.out.println("s = " + s);
// 调用静态方法
baseInfo();
}
public void method() {
System.out.println("method() ....");
}
}
5.Person类 2 测试
package com.yfs.javase;
public class PersonTest {
public static void main(String[] args) {
Person p1 = new Person("张三",20,'男',false);
Person p2 = new Person();
Person p3 = new Person("李四");
}
}
6.Person类3 (private 属性、方法、get/set方法)
package com.yfs.javase;
public class Person {
// 属性私有private
private String name = "Jack";// 每个对象上分配 与对象绑定
private int age;
private char sex;
private boolean married;
static String country = "中国";// 静态属性 与类绑定 所有对象共享
//查看对象的属性值
public String toString() {
return "name = " + name + ", age = " + age + ", sex = " + sex + ", married = " + married;
}
{
name = "Tom";
}
// 设置方法 参数
// public void setAge(int age) {
// if (age > 150) {
// System.out.println("年龄不合法");
// return;
// }
// this.age = age;
// }
//
// // 获取的方法
// public int getAge() {
// return age;
// }
// 通过get set方法 设置 获取属性的值
public Person() {
System.out.println("创建Person对象");
}
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 char getSex() {
return sex;
}
public void setSex(char sex) {
this.sex = sex;
}
public boolean isMarried() {
return married;
}
public void setMarried(boolean married) {
this.married = married;
}
public Person(String name) {
this.name = name;
}
public Person(String name, int age, char sex, boolean married) {
this.name = name;
this.age = age;
this.sex = sex;
this.married = married;
}
public static void baseInfo() {// 静态方法 与类绑定 所有对象共享
System.out.println("舌尖上的中国...");
//method();静态方法不能访问
}
public void test() {// 非静态方法
System.out.println("call test() ....");
method();//在同一类中私有属性 方法可以调用
}
private void method() {//私有方法 范围在类的内部访问
System.out.println("method() ....");
//test();
baseInfo();
String n = name;
}
}
7.Person类3测试
package com.yfs.javase;
public class PersonTest {
public static void main(String[] args) {
Person p1 = new Person("张三",20,'男',false);
System.out.println(p1.toString());
// System.out.println("p1.name = " + p1.name);
// System.out.println("p1.age = " + p1.age);
// System.out.println("p1.sex = " + p1.sex);
// System.out.println("p1.married = " + p1.married);
//p1.name = "张飞";
//修改年龄 通过方法
//p1.age = 2000;
p1.setAge(2000);
p1.setAge(28);
p1.setName("张XX");
System.out.println("p1.getName() = " + p1.getName());
System.out.println("p1.getAge() = " + p1.getAge());
System.out.println("p1状态： " + p1.toString());
p1 = new Person("张三",21,'男',false);
//p1.method();//私有方法不能访问
}
}
8.单例对象 模型
package com.yfs.javase;
public class Singleton {
private Singleton () {
}
//通过一个对象 声明static
public static Singleton getInstance() {
Singleton s = new Singleton();
return s;
}
public void eat() {
System.out.println("eat().....");
}
}
9.单例对象测试
package com.yfs.javase;
public class Test {
public static void main(String[] args) {
//Singleton sing = new Singleton();
Singleton sing = Singleton.getInstance();
sing.eat();
}
}