dao出错，好像无法连接数据库

Question

四月 15, 2019 4:19:44 下午 org.springframework.test.context.support.DefaultTestContextBootstrapper getDefaultTestExecutionListenerClassNames
信息: Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]
四月 15, 2019 4:19:44 下午 org.springframework.test.context.support.DefaultTestContextBootstrapper getTestExecutionListeners
信息: Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@1e67b872, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@60addb54, org.springframework.test.context.support.DependencyInjectionTestExecutionListener@3f2a3a5, org.springframework.test.context.support.DirtiesContextTestExecutionListener@4cb2c100, org.springframework.test.context.transaction.TransactionalTestExecutionListener@6fb554cc, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener@614c5515]
四月 15, 2019 4:19:44 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from class path resource [spring/spring-dao.xml]
四月 15, 2019 4:19:44 下午 org.springframework.context.support.GenericApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.GenericApplicationContext@7dc7cbad: startup date [Mon Apr 15 16:19:44 CST 2019]; root of context hierarchy
四月 15, 2019 4:19:44 下午 com.mchange.v2.log.MLog
信息: MLog clients using java 1.4+ standard logging.
四月 15, 2019 4:19:44 下午 com.mchange.v2.c3p0.C3P0Registry banner
信息: Initializing c3p0-0.9.1.2 [built 21-May-2007 15:04:56; debug? true; trace: 10]

Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!

The error may exist in file [D:\workplace\o2o\target\classes\mapper\AreaDao.xml]

The error may involve com.zzh.o2o.dao.AreaDao.queryArea

The error occurred while executing a query

Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!

请教下老师该怎么更正

Answer 1

翔仔 2019-04-16 00:05:42

同学好，我感觉是你用了mysql8而用的是mysql5的驱动。建议在没有类似解决问题的能力之前，还是先用目前市面依然主流的mysql5.x，否则要把c3p0和相关数据库jdbc版本调整到最新，并且后续mysql8在主从同步的grant语句语法也不一样

• 提问者 AKIRA_ZZH #1

  老师我查看了下，我的mysql版本就是5.7.21的，然后我看了下5.7和5.5之间好像在连接上有差别，不知道老师录视频的时候mysql的具体版本是多少呢

• 提问者 AKIRA_ZZH #2

  非常感谢！老师我发现了mysql5.7的jdbc配置和mysql5.5是有不同的
  jdbc.driver=com.mysql.cj.jdbc.Driver
  jdbc.url=jdbc:mysql://localhost:3306/o2o?useSSL=false&characterEncoding=utf-8&serverTimezone=UTC
  jdbc.username=root
  jdbc.password=123456
  这个才是5.7的正确jdbc然后在pom.xml里还需要修改mysql的和c3p0的版本
  <dependency>
  	<groupId>mysql</groupId>
  	<artifactId>mysql-connector-java</artifactId>
  	<version>8.0.11</version>
  </dependency>
     <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.4</version>
      </dependency>
  这是我的配置，现在junit已经测试成功了！！！

• 翔仔 回复 提问者 AKIRA_ZZH #3

  赞同学解决问题的能力，我视频里用的是mysql5.7.18的版本

Answer 2

提问者 AKIRA_ZZH 2019-04-15 23:53:21

我觉得有可能是我的spring-dao.xml中的配置出了问题

Answer 3

提问者 AKIRA_ZZH 2019-04-15 23:52:09

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException:

### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!

### The error may exist in file [D:\workplace\o2o\target\classes\mapper\AreaDao.xml]

### The error may involve com.zzh.o2o.dao.AreaDao.queryArea

### The error occurred while executing a query

### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database!

这个是错误测试的报告，我认为应该是数据库没有连接成功，但是我也不知道哪里出了错误

• qq_慕少2290290 #1

  你好我是mysql版本是：Server version: 5.7.28-log MySQL Community Server (GPL)
  我按照你改了加了cj和修改的pom还是不行。。你说spring-dao的问题是什么问题呢？