This is the error reason:
警告: Connection has been abandoned PooledConnection[oracle.jdbc.driver.T4CConnection@36583eaf]:java.lang.Exception at org.apache.tomcat.jdbc.pool.ConnectionPool.getThreadDump(ConnectionPool.java:1096) at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:735) at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:664) at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:482) at org.apache.tomcat.jdbc.pool.ConnectionPool. (ConnectionPool.java:156) at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116) at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103) at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:560) at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:245) at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:141) at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321) at org.apache.naming.NamingContext.lookup(NamingContext.java:848) at org.apache.naming.NamingContext.lookup(NamingContext.java:173) at org.apache.catalina.core.NamingContextListener.addResource(NamingContextListener.java:1110) at org.apache.catalina.core.NamingContextListener.createNamingContext(NamingContextListener.java:689) at org.apache.catalina.core.NamingContextListener.lifecycleEvent(NamingContextListener.java:273) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:750) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.startup.Catalina.start(Catalina.java:693) 1: 排查过jdk版本(jdk1.7)与数据库驱动(ojdbc6)的匹配; Telnet test database port is also pass; Database testing is also connected!
2: clear the cache and not restart
3: it worked before, is the data source connected, kill off a tomcat process, will not be able to restart the application and restart the warning has been an error!

Pray god guide