CannotAcquireLockException 锁超时

CannotAcquireLockException 锁超时

表锁和行锁

表锁：在添加数据时把整个表锁住

行锁：在添加数据时只锁添加数据的一行

增加索引把表锁改变为行锁

栏位：username 索引类型： UNIQUE

//main
public static void main(String[] args) {
    ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
    AccountService accountService = ctx.getBean(AccountService.class);
    accountService.update3();
}

//update3

public void update3() {
    jdbcTemplate.update("update tase set money = ? where username=?;", 00, "aa");
    accountService2.update4();
    int i = 1 / 0;
}

//update3

public void update4() {
    jdbcTemplate.update("update tase set money = ? where username=?;", 00, "bb");
}

//xml

<tx:advice id="txAdvice" transaction-manager="transactionManager">
    <tx:attributes>
        <!--以add开始的方法添加事务-->
        <tx:method name="add*"/>
        <tx:method name="insert*"/>
        <tx:method name="delete*"/>
        <tx:method name="update3" propagation="REQUIRED"/><!--REQUIRED为默认的-->
        <tx:method name="update4" propagation="REQUIRES_NEW"/>
    </tx:attributes>
</tx:advice>