Java 实例 - 获取线程id

以下实例演示了如何使用 getThreadId() 方法获取线程id：

Main.java 文件

public   class   Main   extends   Object   implements   Runnable   {
   private   ThreadID   var ;

   public   Main ( ThreadID   v )   {
     this . var  =  v ;
   }

   public   void   run ( )   {
     try   {
       print ( " var getThreadID = "  +  var . getThreadID ( ) ) ;
       Thread . sleep ( 2000 ) ;
       print ( " var getThreadID = "  +  var . getThreadID ( ) ) ;
     }   catch   ( InterruptedException   x )   {
     }
   }

   private   static   void   print ( String   msg )   {
     String   name  =  Thread . currentThread ( ) . getName ( ) ;
     System . out . println ( name  +  " :  "  +  msg ) ;
   }

   public   static   void   main ( String [ ]   args )   {
     ThreadID   tid  =  new   ThreadID ( ) ;
     Main   shared  =  new   Main ( tid ) ;

     try   {
       Thread   threadA  =  new   Thread ( shared ,  " threadA " ) ;
       threadA . start ( ) ;

       Thread . sleep ( 500 ) ;

       Thread   threadB  =  new   Thread ( shared ,  " threadB " ) ;
       threadB . start ( ) ;

       Thread . sleep ( 500 ) ;

       Thread   threadC  =  new   Thread ( shared ,  " threadC " ) ;
       threadC . start ( ) ;
     }   catch   ( InterruptedException   x )   {
     }
   }
}

class   ThreadID   extends   ThreadLocal   {
   private   int   nextID ;

   public   ThreadID ( )   {
     nextID  =  10001 ;
   }

   private   synchronized   Integer   getNewID ( )   {
     Integer   id  =  new   Integer ( nextID ) ;
     nextID ++;
     return   id ;
   }

        protected   Object   initialValue ( )   {
     print ( " in initialValue() " ) ;
     return   getNewID ( ) ;
   }

   public   int   getThreadID ( )   {
     Integer   id  =  ( Integer )   get ( ) ;
     return   id . intValue ( ) ;
   }

   private   static   void   print ( String   msg )   {
     String   name  =  Thread . currentThread ( ) . getName ( ) ;
     System . out . println ( name  +  " :  "  +  msg ) ;
   }
}

以上代码运行输出结果为：

threadA: in initialValue()

threadA: var getThreadID =10001

threadB: in initialValue()

threadB: var getThreadID =10002

threadC: in initialValue()

threadC: var getThreadID =10003

threadA: var getThreadID =10001

threadB: var getThreadID =10002

threadC: var getThreadID =10003

程序猿的技术大观园：www.javathinker.net

[这个贴子最后由 flybird 在 2020-01-26 21:05:27 重新编辑]

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