/** 

*    

*/  
package  concurent; 

/* 

* Thread 

*/  
class  Person  extends  Thread{ 
  Bank bank= null ; 
   int  from; 
   int  to; 
   double  amount; 
   public  Person(Bank bank2,  int  i,  int  j,  double  d) { 
     this .bank=bank2; 
     this .from=i; 
     this .to=j; 
     this .amount=d; 
  } 

   public   void  run(){ 
     //get bank size 
    System.out.println( "The bank size:" +bank.size()); 
     //out accounts 
    bank.out(); 
     //transfer 
     try  { 
      bank.transfer(from, to, amount); 
    }  catch  (InterruptedException e) { 
       // TODO Auto-generated catch block 
      e.printStackTrace(); 
    } 
     //out accounts    
    bank.out(); 
  } 
} 

/** 

* @author daniel    

* This case main show three thread transfer money in the same bank 

*/  
public   class  BankTest { 

   /** 

    * @param args 

    */  
   public   static   void  main(String[] args) { 
    Bank bank= new  Bank(3,100.00); 
    Person p1= new  Person(bank,0,1,50.00); 
    Person p2= new  Person(bank,0,1,100.00); 
    Person p3= new  Person(bank,1,0,60.00); 
    p1.start(); 
    p2.start(); 
    p3.start(); 
  } 
} 

/** 

* Bank model 

* @author daniel 

* 

*/  
class  Bank { 
   private   final   double [] accounts;    
     
   /** 

    * Constructs the bank 

    * @param n 

    * @param initialBalance 

    */  
   public  Bank( int  n,  double  initialBalance){ 
    accounts= new   double [n]; 
     for ( int  i=0;i<accounts.length;i++){ 
      accounts[i]=initialBalance;        
    } 
  } 
    
   /** 

    * Transfers money from one account to another 

    * @param from 

    * @param to 

    * @param amount 

    * @throws InterruptedException 

    */  
   public   synchronized   void  transfer( int  from,  int  to,  double  amount)  throws  InterruptedException{ 
     while (accounts[from]<amount) 
      wait(); 
    System.out.println(Thread.currentThread()); 
    accounts[from] -=amount; 
    System.out.printf( "%10.2f from %d to %d" ,amount,from,to); 
    accounts[to] +=amount; 
    System.out.printf( "     Total Balance: %10.2f%n" , getTotalBalance()); 
    notifyAll(); 
  } 

   /** 

    * Gets the sum of all account balances 

    * @return 

    */  
   public   synchronized   double  getTotalBalance() { 
     double  sum =0 ;     
     for ( double  a : accounts){ 
      sum+=a; 
    } 
     return  sum; 
  } 
    
   public   void  out(){ 
     for ( int  i=0;i<accounts.length;i++){ 
      System.out.println( "accounts[" +i+ "]:" +accounts[i]); 
    } 
  } 
   /** 

    * get the number of accounts in the bank 

    * @return 

    */  
   public   int  size(){ 
     return  accounts.length; 
  } 

} 

     本文转自danni505 51CTO博客，原文链接：http://blog.51cto.com/danni505/212649，如需转载请自行联系原作者