springmvc连接数据库时，报连接失败了？？？

时间：2022-02-25 04:33:46
首先看配置文件applicationContext.xml 
<beans xmlns="http://www.springframework.org/schema/beans"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xmlns:aop="http://www.springframework.org/schema/aop"

    xmlns:tx="http://www.springframework.org/schema/tx"

    xmlns:context="http://www.springframework.org/schema/context"

    xsi:schemaLocation="http://www.springframework.org/schema/beans

        http://www.springframework.org/schema/beans/spring-beans-4.3.xsd

        http://www.springframework.org/schema/aop

        http://www.springframework.org/schema/aop/spring-aop.xsd

        http://www.springframework.org/schema/tx

        http://www.springframework.org/schema/tx/spring-tx.xsd

       http://www.springframework.org/schema/context

       http://www.springframework.org/schema/context/spring-context.xsd">

	<!-- 扫描注解所在的包 -->       

	<context:component-scan base-package="cn.jzh"></context:component-scan> 

	<!-- 加载jdbc配置 -->

   <bean class="org.springframework.beans.factory.config.PreferencesPlaceholderConfigurer">

   		<property name="location" value="classpath:jdbc.properties"></property>

   </bean>

   <!-- 配置datasource -->

   <bean id ="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

   		<property name="driverClass" value="${driver}"></property>

   		<property name="jdbcUrl" value="${url}"></property>

   		<property name="user" value="${name}"></property>

   		<property name="password" value="${pass}"></property>

   </bean>

    <!-- 配置sqlsessionFactory -->

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

    	<property name="dataSource" ref="dataSource"></property>

    	<property name="mapperLocations" value="classpath:cn/jzh/mapper/*Mapper.xml"></property>

    </bean>

   <!-- 3.配置MapperScannerConfigurer，用于扫描指定包下的Mapper接口，

     	生成代理对象的id为Mapper接口名第一个字母小写(userinfoMapper) --> 

   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">

   		<property name="basePackage" value="cn.jzh.mapper"></property>

   		<property name="sqlSessionFactory" ref="sqlSessionFactory"></property>

   </bean>

   <!-- 声明事务 -->

   <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  

   		<property name="dataSource" ref="dataSource"></property>

   </bean>

   <tx:advice id="txAdvice" transaction-manager="transactionManager">

   		<tx:attributes>

   			<tx:method name="*" propagation="REQUIRED"/>

   		</tx:attributes>

   </tx:advice>

   <aop:config>

   		<aop:pointcut expression="execution(* cn.jzh.service.*.*(..))" id="myPointcut"/>

   		<aop:advisor advice-ref="txAdvice" pointcut-ref="myPointcut"/>

   </aop:config>

再看jdbc.properties配置文件 
driver=com.mysql.driver.Driver

url=jdbc:mysql://127.0.0.1:3306/springmvc

name=root

pass=root

再看springmvc.xml配置文件 
<beans xmlns="http://www.springframework.org/schema/beans"

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

       xmlns:context="http://www.springframework.org/schema/context"

       xmlns:mvc="http://www.springframework.org/schema/mvc"

       xsi:schemaLocation="http://www.springframework.org/schema/beans

      http://www.springframework.org/schema/beans/spring-beans.xsd

      http://www.springframework.org/schema/mvc

      http://www.springframework.org/schema/mvc/spring-mvc.xsd

      http://www.springframework.org/schema/context

      http://www.springframework.org/schema/context/spring-context.xsd">

      <!-- 扫面注解 -->

      <context:component-scan base-package="cn.jzh"></context:component-scan>

      <!-- 映射器和处理器 -->

      <mvc:annotation-driven></mvc:annotation-driven>

      <!-- 视图解析 -->

      <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">

      	<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property>

      	<property name="prefix" value="/WEB-INF/view/"></property>

      	<property name="suffix" value=".jsp"></property>

      </bean>

</beans>


再看看web.xml的配置文件： 
<context-param>

  	<param-name>contextConfigLocation</param-name>

  	<param-value>classpath:applicationContext.xml</param-value>

  </context-param>

  <listener>

  	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

  </listener>

  <filter>

  	<filter-name>encoding</filter-name>

  	<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>

  	<init-param>

  		<param-name>encoding</param-name>

  		<param-value>UTF-8</param-value>

  	</init-param>

  </filter>

  <filter-mapping>

  	<filter-name>encoding</filter-name>

  	<url-pattern>/*</url-pattern>

  </filter-mapping>

  <servlet>

  	<servlet-name>springmvc</servlet-name>

  	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

  	<init-param>

  		<param-name>contextConfigLocation</param-name>

  		<param-value>classpath:springmvc.xml</param-value>

  	</init-param>

  </servlet>

  <servlet-mapping>

  	<servlet-name>springmvc</servlet-name>

  	<url-pattern>/</url-pattern>

  </servlet-mapping>


再看controller层： 
@Controller

@RequestMapping("/user")

public class UserController {

	@Resource(name="userService")

	private UserService service;


	@RequestMapping("/list")

	public String list(Model model){

		List<User> list = service.getAll();

		model.addAttribute("list",list);

		return "list";

	}

}

index.jsp的页面就这一句话：
<a href="user/list">用户列表显示</a>

另外：（1）项目启动的时候，没有报错；
（2）如果把连接数据库那一块直接写死，即把jdbc.properties文件里面的内容直接写在那里就可以直接连接上去了
（3）jdbc.properties配置文件是没问题的，我在另一个项目里面测试了是可以直接使用的，每一行末尾没有加空格
（4）我在网上查了后，在jdk/jre/lib/exc（貌似是这个路径）文件夹下添加了mysql-connector-java-5.1.40.jar，发现还是没用，索性就又删除了
附：报错示例： 
java.lang.ClassNotFoundException: ${driver}

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1291)

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)

	at java.lang.Class.forName0(Native Method)

	at java.lang.Class.forName(Class.java:264)

	at com.mchange.v2.c3p0.DriverManagerDataSource.ensureDriverLoaded(DriverManagerDataSource.java:143)

	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:173)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206)

	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)

	at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)

	at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)

	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

2018-09-10 10:15:01,126 [C3P0PooledConnectionPoolManager[identityToken->1b607sx9x1hmebr7ojt0vu|462f8574]-HelperThread-#1] DEBUG [com.mchange.v2.resourcepool.BasicResourcePool] - An exception occurred while acquiring a poolable resource. Will retry.

java.sql.SQLException: No suitable driver

	at java.sql.DriverManager.getDriver(DriverManager.java:315)

	at com.mchange.v2.c3p0.DriverManagerDataSource.driver(DriverManagerDataSource.java:285)

	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:175)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206)

	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)

	at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)

	at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1870)

	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

2018-09-10 10:15:02,064 [C3P0PooledConnectionPoolManager[identityToken->1b607sx9x1hmebr7ojt0vu|462f8574]-HelperThread-#0] WARN  [com.mchange.v2.c3p0.DriverManagerDataSource] - Could not load driverClass ${driver}

java.lang.ClassNotFoundException: ${driver}

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1291)

	at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1119)

	at java.lang.Class.forName0(Native Method)

	at java.lang.Class.forName(Class.java:264)

	at com.mchange.v2.c3p0.DriverManagerDataSource.ensureDriverLoaded(DriverManagerDataSource.java:143)

	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:173)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:220)

	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:206)

	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:203)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1138)

	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1125)

	at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)

	at com.mchange.v2.reso


6 个解决方案

#1

driver=com.mysql.driver.Driver
把这句话换成
driver=com.mysql.jdbc.Driver

#2

引用 1 楼 t15137830 的回复:
driver=com.mysql.driver.Driver
把这句话换成
driver=com.mysql.jdbc.Driver

我试了一下，没什么用啊，跪求大神的指点

#3

看下你的target里面是否有jdbc.properties这个文件

#4

错误提示没找到${driver}属性，有可能没读到配置，可以先注释掉${driver}，看是否{url}也读取不到
<!-- 配置datasource -->
   <bean id ="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
           <!--<property name="driverClass" value="${driver}"></property>-->
           <property name="jdbcUrl" value="${url}"></property>
           <property name="user" value="${name}"></property>
           <property name="password" value="${pass}"></property>
   </bean>

#5

非常感谢大家的支持，问题我发现了，原来是数据库连接池的问题，用的是v2.c3p0,就尽量不要使用MapperScannerConfigurer这个插件，要不然会一直报连接异常，最好办法是用常用的数据库连接池比如：德鲁伊的就很好，兼容性非常棒

#6

引用 5 楼 u012060033 的回复:
非常感谢大家的支持，问题我发现了，原来是数据库连接池的问题，用的是v2.c3p0,就尽量不要使用MapperScannerConfigurer这个插件，要不然会一直报连接异常，最好办法是用常用的数据库连接池比如：德鲁伊的就很好，兼容性非常棒

再补充一点，用了v2.c3p0，又用了MapperScannerConfigurer干脆就把数据库连接那里写死得了

#1

driver=com.mysql.driver.Driver
把这句话换成
driver=com.mysql.jdbc.Driver

#2

引用 1 楼 t15137830 的回复:
driver=com.mysql.driver.Driver
把这句话换成
driver=com.mysql.jdbc.Driver

我试了一下，没什么用啊，跪求大神的指点

#3

看下你的target里面是否有jdbc.properties这个文件

#4

错误提示没找到${driver}属性，有可能没读到配置，可以先注释掉${driver}，看是否{url}也读取不到
<!-- 配置datasource -->
   <bean id ="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
           <!--<property name="driverClass" value="${driver}"></property>-->
           <property name="jdbcUrl" value="${url}"></property>
           <property name="user" value="${name}"></property>
           <property name="password" value="${pass}"></property>
   </bean>

#5

非常感谢大家的支持，问题我发现了，原来是数据库连接池的问题，用的是v2.c3p0,就尽量不要使用MapperScannerConfigurer这个插件，要不然会一直报连接异常，最好办法是用常用的数据库连接池比如：德鲁伊的就很好，兼容性非常棒

#6

引用 5 楼 u012060033 的回复:
非常感谢大家的支持，问题我发现了，原来是数据库连接池的问题，用的是v2.c3p0,就尽量不要使用MapperScannerConfigurer这个插件，要不然会一直报连接异常，最好办法是用常用的数据库连接池比如：德鲁伊的就很好，兼容性非常棒

再补充一点，用了v2.c3p0，又用了MapperScannerConfigurer干脆就把数据库连接那里写死得了
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