多线程--ThreadLocal

刺骨的言语ヽ痛彻心扉 2023-07-13 05:55 5阅读 0赞

原文网址：[多线程--ThreadLocal\_IT利刃出鞘的博客-CSDN博客][--ThreadLocal_IT_-CSDN]

# 其他网址 #

[（基础系列）ThreadLocal的用法、原理和用途 - SegmentFault 思否][ThreadLocal_ - SegmentFault]  
[JAVA中ThreadLocal用法介绍\_蒋固金（jianggujin）的专栏-CSDN博客\_threadlocal用法][JAVA_ThreadLocal_jianggujin_-CSDN_threadlocal]

# 简介 #

## **方法** ##

<table style="width:500px;"> 
 <tbody> 
  <tr> 
   <td style="width:157px;"><strong>方法</strong></td> 
   <td style="width:342px;"><strong>说明</strong></td> 
  </tr> 
  <tr> 
   <td style="width:157px;">void set(T value)</td> 
   <td style="width:342px;"></td> 
  </tr> 
  <tr> 
   <td style="width:157px;">T get()</td> 
   <td style="width:342px;"></td> 
  </tr> 
  <tr> 
   <td style="width:157px;">void remove()</td> 
   <td style="width:342px;"></td> 
  </tr> 
 </tbody> 
</table>

## 场景 ##

**其他网址**

> [ThreadLocal作用、场景、原理 - 简书][ThreadLocal_ -]

**数据库连接**

>     public Connection initialValue() {
>         return DriverManager.getConnection(DB_URL);
>     }
>     
>     public static Connection getConnection() {  
>         return connectionHolder.get();
>     }

**Session管理**

>     public static Session getSession() throws InfrastructureException {  
>         Session s = (Session) threadSession.get();
>         try {
>             if (s == null) {
>                 s = getSessionFactory().openSession();
>                 threadSession.set(s);
>             }
>         } catch (HibernateException ex) {
>             throw new InfrastructureException(ex);
>         }
>         return s;
>     }

# 实例 #

**单个**

>     package org.example.a;
>     
>     public class Demo {
>         static ThreadLocal<String> localVariable = new ThreadLocal<>();
>     
>         static void print(String str){
>             System.out.println(str + ":" + localVariable.get());
>         }
>     
>         public static void main(String[] args) {
>             Thread thread1 = new Thread(new Runnable() {
>                 @Override
>                 public void run() {
>                     localVariable.set("abc");
>                     print("thread1 variable");
>                 }
>             });
>     
>             Thread thread2 = new Thread(new Runnable() {
>                 @Override
>                 public void run() {
>                     localVariable.set("def");
>                     print("thread2 variable");
>                 }
>             });
>     
>             thread1.start();
>             thread2.start();
>         }
>     }
> 
> 运行结果
> 
>     thread1 variable:abc
>     thread2 variable:def

**多个**

>     package org.example.a;
>     
>     public class Demo {
>         static ThreadLocal<String> localVariable = new ThreadLocal<>();
>         static ThreadLocal<String> localVariable2 = new ThreadLocal<>();
>     
>         static void print(String str){
>             System.out.println(str + ":" + localVariable.get());
>             System.out.println(str + ":" + localVariable2.get());
>         }
>     
>         public static void main(String[] args) {
>             Thread thread1 = new Thread(new Runnable() {
>                 @Override
>                 public void run() {
>                     localVariable.set("abc");
>                     localVariable2.set("abc2");
>                     print("thread1 variable");
>                 }
>             });
>     
>             Thread thread2 = new Thread(new Runnable() {
>                 @Override
>                 public void run() {
>                     localVariable.set("def");
>                     localVariable2.set("def2");
>                     print("thread2 variable");
>                 }
>             });
>     
>             thread1.start();
>             thread2.start();
>         }
>     }
> 
> 运行结果
> 
>     thread1 variable:abc
>     thread1 variable:abc2
>     thread2 variable:def
>     thread2 variable:def2

# 原理 #

**其他网址**

> [ThreadLocal的使用及解析\_implements-CSDN博客\_threadlocal的用法][ThreadLocal_implements-CSDN_threadlocal]  
> [ThreadLocal用法详解和原理 - coshaho - 博客园][ThreadLocal_ - coshaho -]
> 
> 见：《Java并发编程之美》=> 1.11.2 ThreadLocal 的实现原理

[--ThreadLocal_IT_-CSDN]: https://knife.blog.csdn.net/article/details/104785422
[ThreadLocal_ - SegmentFault]: https://segmentfault.com/a/1190000011264294
[JAVA_ThreadLocal_jianggujin_-CSDN_threadlocal]: https://blog.csdn.net/jianggujin/article/details/51064034
[ThreadLocal_ -]: https://www.jianshu.com/p/6fc3bba12f38
[ThreadLocal_implements-CSDN_threadlocal]: https://blog.csdn.net/u013320868/article/details/80772482
[ThreadLocal_ - coshaho -]: https://www.cnblogs.com/coshaho/p/5127135.html