一、在多线程环境下创建单例
方式一:
1
2
3
4
5
6
7
8
9
10
11
12
|
package com.ietree.multithread.sync; public class Singletion { private static class InnerSingletion { private static Singletion single = new Singletion(); } public static Singletion getInstance() { return InnerSingletion.single; } } |
方式二:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
package com.ietree.multithread.sync; public class DubbleSingleton { private static DubbleSingleton ds; public static DubbleSingleton getDs() { if (ds == null ) { try { // 模拟初始化对象的准备时间... Thread.sleep( 3000 ); } catch (InterruptedException e) { e.printStackTrace(); } synchronized (DubbleSingleton. class ) { if (ds == null ) { // 这个判断很重要,如果没有那将不是单例,而是多例 ds = new DubbleSingleton(); } } } return ds; } public static void main(String[] args) { Thread t1 = new Thread( new Runnable() { @Override public void run() { System.out.println(DubbleSingleton.getDs().hashCode()); } }, "t1" ); Thread t2 = new Thread( new Runnable() { @Override public void run() { System.out.println(DubbleSingleton.getDs().hashCode()); } }, "t2" ); Thread t3 = new Thread( new Runnable() { @Override public void run() { System.out.println(DubbleSingleton.getDs().hashCode()); } }, "t3" ); t1.start(); t2.start(); t3.start(); } } |
感谢阅读,希望能帮助到大家,谢谢大家对本站的支持!
原文链接:http://www.cnblogs.com/Dylansuns/p/6719764.html