1.概念:
对业务写方法加锁,对业务读方法不加锁,容易产生脏读问题(dirtyRead)
2.代码:
public class Account { String name; double balance; public synchronized void set(String name, double balance) { this.name = name; try { Thread.sleep(2000); } catch (InterruptedException e) { e.printStackTrace(); } this.balance = balance; } public /*synchronized*/ double getBalance(String name) { return this.balance; } public static void main(String[] args) { Account a = new Account(); new Thread(()->a.set("zhangsan", 100.0)).start(); try { TimeUnit.SECONDS.sleep(1); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println(a.getBalance("zhangsan")); try { TimeUnit.SECONDS.sleep(2); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println(a.getBalance("zhangsan")); } }