druid1.2.8以上的版本中jdbc:mysql:loadbalance://执行超过10秒会报超时错误 #5396

1.2.8以上版本,当协议是jdbc:mysql:loadbalance://时,查询超过10秒就会报错.
经过验证发现1.2.8以上的版本中新增了一个socketTimeout属性,而这个属性在1.2.8以上的版本中无论是connectionProperties中设置还是直接在url中设置都不生效.只能在获取到数据源对象后,手动设置一下才可以.
如果我把协议换成jdbc:mysql://时,则1.2.8以上在url中加上socketTimeout也可以支持.但是这样就不支持集群了,只能固定一个数据库地址查询.
如果把druid换成1.2.8版本,则不需要配置socketTimeout这些属性就不会报错,推测1.2.8及以下的版本是读取的maxWait这个属性.
`com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet successfully received from the server was 10,090 milliseconds ago. The last packet sent successfully to the server was 10,090 milliseconds ago.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeInternal(ClientPreparedStatement.java:974)
at com.mysql.cj.jdbc.ClientPreparedStatement.executeQuery(ClientPreparedStatement.java:1024)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.mysql.cj.jdbc.ha.MultiHostConnectionProxy$JdbcInterfaceProxy.invoke(MultiHostConnectionProxy.java:105)
at com.sun.proxy.$Proxy88.executeQuery(Unknown Source)
at com.alibaba.druid.pool.DruidPooledPreparedStatement.executeQuery(DruidPooledPreparedStatement.java:213)`