最近调试安卓连接mysql真是心态爆炸,快两天才搞出来.以下整理一些常见问题. 检查manifest文件里网络权限是否打开 检查数据库IP是否有问题(包括一些沙雕错误,比如是不是在ip首或尾多了个空格..) 检查连接url是否正确,应为jdbc:mysql://ip:3306/dbname 检查connect J 版本是否对应 持续更新…

一.背景 最近在家里捣鼓一个公司自己搭建的demo的时候,发现程序一启动就会出现CommunicationsException: Communications link failure错误,经过一番排查最后发现是数据库url写错造成的,这个过程中也对出现这个错误的解决思路有了一些自己的理解,现和大家分享.该错误的具体信息如下: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure…

现象: 报错:Exception in thread "main" com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure 解决办法: 更换 mysql-connector-java-8.0.11.jar 为 mysql-connector-java-8.0.16.jar, 下载位置:https://mvnrepository.com/artifact/mysql/mysql-c…

2017-12-29 10:43:19,776 ERROR [com.alibaba.druid.pool.DruidDataSource] - <init datasource error, url: jdbc:mysql://localhost:3306/hxrc> com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the serv…

详细报错 java.sql.SQLException: The server time zone value '�й���׼ʱ��' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time z…

连接池配置中配上:<property name="validationQuery" value="SELECT 1 FROM DUAL" />…

解决方案 连接Mysql报错 The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. 检查mysql服务是否开启…

问题描述 App Service使用jdbc连接MySQL服务,出现大量的  Communications link failure: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received…

-- 查询mysql 数据库链接空闲时间持有最大空闲时间,单位为秒 SHOW VARIABLES WHERE VAriable_name = 'interactive_timeout'; -- 会出现wait_timeout与该参数意思相近,修改时,一起修改 SHOW VARIABLES WHERE VAriable_name = '%timeout'; -- 解决问题 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Commun…

前端时间到客户那去进行项目的上线测试,将项目部署好之后,运行都是正常的,可是每到了第二天早上访问的时候,就会报一个Could not open Hibernate session for transaction 异常,Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception,当时很摸不着头脑,后来就开始从数据库连接的源头开始找,本次项目中用的…