简单的写了一个学生类一个老师类，一种是饿汉式一种是懒汉式：

1. <p>public class Student {
   
2. // 构造方法私有化，不让外界创建对象
   
3. private Student() {
   
4. }</p><p> // 创建对象
   
5. private static Student s = new Student();</p><p> // 提供公共的访问方法
   
6. public static Student getStuden() {
   
7.   return s;
   
8. }</p><p>}
   
9. 
   
10. public class Teacher {
    
11. // 构造方法私有化
    
12. private Teacher() {
    
13. }</p><p> //延迟加载
    
14. private static Teacher t = null;
    
15. public synchronized static Teacher getTeacher() {
    
16.   if (t == null) {
    
17.    t = new Teacher();
    
18.   }
    
19.   return t;
    
20. }
    
21. }</p><p>public class TestDemo {
    
22. public static void main(String[] args) {
    
23.   Student s1 = Student.getStuden();
    
24.   Student s2 = Student.getStuden();
    
25.   Teacher t1 = Teacher.getTeacher();
    
26.   Teacher t2 = Teacher.getTeacher();
    
27.   System.out.println(s1 == s2);
    
28.   System.out.println(t1 == t2);
    
29. }
    
30. }
    
31. </p>

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简单的写了一个学生类一个老师类，一种是饿汉式一种是懒汉式：

1. <p>public class Student {
   
2. // 构造方法私有化，不让外界创建对象
   
3. private Student() {
   
4. }</p><p> // 创建对象
   
5. private static Student s = new Student();</p><p> // 提供公共的访问方法
   
6. public static Student getStuden() {
   
7.   return s;
   
8. }</p><p>}
   
9. 
   
10. public class Teacher {
    
11. // 构造方法私有化
    
12. private Teacher() {
    
13. }</p><p> //延迟加载
    
14. private static Teacher t = null;
    
15. public synchronized static Teacher getTeacher() {
    
16.   if (t == null) {
    
17.    t = new Teacher();
    
18.   }
    
19.   return t;
    
20. }
    
21. }</p><p>public class TestDemo {
    
22. public static void main(String[] args) {
    
23.   Student s1 = Student.getStuden();
    
24.   Student s2 = Student.getStuden();
    
25.   Teacher t1 = Teacher.getTeacher();
    
26.   Teacher t2 = Teacher.getTeacher();
    
27.   System.out.println(s1 == s2);
    
28.   System.out.println(t1 == t2);
    
29. }
    
30. }
    
31. </p>

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