1 package com.dengbaobao; 2 public class Barry$June_person { 3 public static void main(String args[]) { 4 new Person(); 5 new Person(); 6 new Person(); 7 new Person(); 8 new Person(); 9 10 } 11 } 12 class Person{ 13 private String name; 14 private static int count; 15 public Person() { 16 count++; 17 System.out.println("产生了" + count +"个实例化对象。 "); 18 } 19 public String getInfo() { 20 return "姓名: " + this.name; 21 } 22 }
1 package com.baidu; 2 3 public class June$1 { 4 5 public static void main(String[] args) { 6 System.out.println(new Person().getInfo()); 7 System.out.println(new Person("A").getInfo()); 8 System.out.println(new Person("B").getInfo()); 9 System.out.println(new Person().getInfo()); 10 11 } 12 } 13 class Person{ 14 private String name; 15 private static int count; 16 public Person() { 17 count++; 18 this.name = "NONAME - "+ count ; 19 } 20 public Person(String name) { 21 this.name=name; 22 23 } 24 public String getInfo() { 25 return "姓名: "+ this.name; 26 } 27 }
1 package com.baidu; 2 public class June$2 { 3 public static void main(String args[]) { 4 Single s = null; 5 s = Single.getInstance(); 6 s.print(); 7 } 8 9 } 10 class Single{ 11 private static Single instance = new Single(); 12 private Single() { 13 14 } 15 public static Single getInstance() { 16 return instance; 17 } 18 public void print() { 19 System.out.println("hello world!!!"); 20 } 21 }
1 package com.bai; 2 public class June$3 { 3 public static void main(String[] args) { 4 Persona per1 = new Persona("张三",30); 5 Persona per2 = new Persona("李四",31); 6 Persona per3 = new Persona("张五",32); 7 System.out.println("---------------------信息修改之前-----------------------------"); 8 System.out.println(per1.getInfo()); 9 System.out.println(per1.getInfo()); 10 System.out.println(per1.getInfo()); 11 System.out.println("---------------------信息修改之后-----------------------------"); 12 Persona.city = "B城"; 13 System.out.println(per1.getInfo()); 14 System.out.println(per1.getInfo()); 15 System.out.println(per1.getInfo()); 16 } 17 18 } 19 class Persona{ 20 private String name; 21 private int age; 22 static String city = "A城"; 23 public Persona(String name,int age) { 24 this.name = name; 25 this.age = age; 26 } 27 public String getInfo() { 28 return " 姓名:"+ this.name + ",年龄:" + this.age + ", 城市: "+city; 29 } 30 }
1 package com.bai; 2 public class StaticDemo { 3 public static void main(String args[]) { 4 for (int x = 0; x < args.length; x++) { 5 System.out.println(args[x] +" . "); 6 } 7 8 } 9 10 }
1 package com.bai; 2 public class Ehanshi { 3 public static void main(String[] args) { 4 Ehanshi s=Ehanshi.getSinglePerson(); 5 System.out.println(s.toString());//得到唯一的对象 6 } 7 8 private String name="The God"; 9 private int age=10000; 10 private static Ehanshi person=new Ehanshi();//生成对象放在java静态池中,否则如果非静态在堆中,生命周期比类短 11 private Ehanshi() {};//构造方法私有化可以避免大量实例化对象而消耗内存 12 public static Ehanshi getSinglePerson() {//静态方法类外部可以通过类名.获取 13 return person; 14 } 15 @Override 16 public String toString() { 17 return "SinglePerson [name=" + name + ", age=" + age + "]"; 18 } 19 20 }