一直显示这个错误 不知道如何解决

Question

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

at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)

at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:573)

at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:812)

at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:868)

at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:876)

at springAccount.AccountDaoImpl.out(AccountDaoImpl.java:9)

at springAccount.AccountServiceImpl.transfer(AccountServiceImpl.java:10)

at springAccount.Start.dem(Start.java:13)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)

at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)

at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)

Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!

at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)

at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:529)

at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:128)

at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)

at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)

... 30 more

Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.

at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1319)

at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)

at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)

at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)

... 33 more

XML文件

<?xml version="1.0" encoding="UTF-8"?>

<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"

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

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

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

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

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

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

<!--  datasource -->

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

<property name="driverClass" value="com.mysql.jdbc.Driver"></property>

<property name="jdbcUrl" value=" jdbc:mysql://localhost:3306/ee19_spring_day03"></property>

<property name="user" value="root"></property>

<property name="password" value="123456"></property>

</bean>

<!--  dao  -->

<bean id="accountDao" class="springAccount.AccountDaoImpl">

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

</bean>

<!--  service -->

<bean id="accountService" class="springAccount.AccountServiceImpl">

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

</bean>

</beans>