C3P0 连接池错误【已解决】-An exception occurred while acquiring a poolable resource. Will retry.

C3P0 连接池出错

今天在学习Spring MyBatis 整合时报错
异常如下：

[com.mchange.v2.resourcepool.BasicResourcePool]-An exception occurred while acquiring a poolable resource. Will retry.
java.sql.SQLException: ORA-01017: invalid username/password; logon denied

	at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:439)
	at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:388)
	at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:381)
	at oracle.jdbc.driver.T4CTTIfun.processError(T4CTTIfun.java:564)
	at oracle.jdbc.driver.T4CTTIoauthenticate.processError(T4CTTIoauthenticate.java:431)
	at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:436)
	at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:186)
	at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:366)
	at oracle.jdbc.driver.T4CTTIoauthenticate.doOAUTH(T4CTTIoauthenticate.java:752)
	at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:359)
	at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
	at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
	at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
	at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
	at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
	at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
	at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
	at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
	at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
	at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
	at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)

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 UserMapper.xml
### The error may involve com.Spring.Mapper.UserMapper.SearUser
### 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!

	at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:77)
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446)
	at com.sun.proxy.$Proxy10.selectOne(Unknown Source)
	at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166)
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:83)
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:59)
	at com.sun.proxy.$Proxy11.SearUser(Unknown Source)
	at com.Spring.Service.UserServiceImpl.SearUser(UserServiceImpl.java:20)
	at SpringTest.test(SpringTest.java:12)
	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 org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)

Process finished with exit code -1

出现的情况是C3P0连接池一直连接数据库，但是一直连接不上 所以频繁连接

具体解决方法如下：
检查db.propreties 文件

正确写法：

jdbc.driver=oracle.jdbc.driver.OracleDriver
jdbc.url=jdbc:oracle:thin:@//localhost:1521/MMH
jdbc.username=MMH
jdbc.password=0124

注：此处一定要加jdbc. ！！！！！！

Spring 配置目录

    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
        <!-- SpringEL 语法 ${key} -->
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <!-- ${username}如果key是username，name 默认spring框架调用的当前操作系统的账号 解决方案：可以统一给key加一个前缀 -->
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean>

需要配置的属性自行配置