java多线程同步除了上文说到的同步代码块，还可以使用同步方法，还是银行取钱的那个问题，代码如下
public class Account
{
private String accountNo;
private double balance;
public Account(){}
public Account(String accountNo , double balance)
{
this.accountNo = accountNo;
this.balance = balance;
}
public void setAccountNo(String accountNo)
{
this.accountNo = accountNo;
}
public String getAccountNo()
{
return this.accountNo;
}
public double getBalance()
{
return this.balance;
}
public synchronized void draw(double drawAmount)
{
if (balance >= drawAmount)
{
System.out.println(Thread.currentThread().getName()
+ "取钱成功！吐出钞票:" + drawAmount);
try
{
Thread.sleep(1);
}
catch (InterruptedException ex)
{
ex.printStackTrace();
}
balance -= drawAmount;
System.out.println("\t余额为: " + balance);
}
else
{
System.out.println(Thread.currentThread().getName()
+ "取钱失败！余额不足");
}
}
public int hashCode()
{
return accountNo.hashCode();
}
public boolean equals(Object obj)
{
if(this == obj)
return true;
if (obj !=null
&& obj.getClass() == Account.class)
{
Account target = (Account)obj;
return target.getAccountNo().equals(accountNo);
}
return false;
}
}
取钱的线程
public class DrawThread extends Thread
{
private Account account;
private double drawAmount;
public DrawThread(String name , Account account
, double drawAmount)
{
super(name);
this.account = account;
this.drawAmount = drawAmount;
}
public void run()
{
account.draw(drawAmount);
}
}
测试类：
public class DrawTest
{
public static void main(String[] args)
{
Account acct = new Account("1234567" , 1000);
new DrawThread("甲" , acct , 800).start();
new DrawThread("乙" , acct , 800).start();
}
}
运行结果：
