Java线程同步Lock同步锁代码示例

package lock.reentrantlock2;import java.util.concurrent.locks.*;public class Account{  //定义锁对象  private final ReentrantLock lock = new ReentrantLock();  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 void draw(double drawAmount)  {    lock.lock();    try    {      //账户余额大于取钱数目      if (balance >= drawAmount)      {        //吐出钞票        System.out.println(Thread.currentThread().getName() +          "取钱成功！吐出钞票:" + drawAmount);        try        {          Thread.sleep(1);              }        catch (InterruptedException ex)        {          ex.printStackTrace();        }        //修改余额        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！");      }         }    finally    {      lock.unlock();    }  }  public int hashCode()  {    return accountNo.hashCode();  }  public boolean equals(Object obj)  {    if (obj != null && obj.getClass() == Account.class)    {      Account target = (Account)obj;      return target.getAccountNo().equals(accountNo);    }    return false;  }}