CannotcreatePoolableConnectionFactory(Communicationslink_MySQL

今天在做web项目的时候碰到了这样的一个异常：

Caused by: java.lang.RuntimeException: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failureThe last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)	at edu.gzucm.yjsglxt.base.util.TimeSetUtils.getTimeSets(TimeSetUtils.java:52)	at edu.gzucm.yjsglxt.base.util.TimeSetUtils.(TimeSetUtils.java:22)	... 3 moreCaused by: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failureThe last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)	at edu.gzucm.yjsglxt.base.util.TimeSetUtils.getTimeSets(TimeSetUtils.java:32)	... 4 moreCaused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failureThe last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)	at java.lang.reflect.Constructor.newInstance(Unknown Source)	at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:346)	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2334)	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2371)	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2163)	at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:794)	at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)	at java.lang.reflect.Constructor.newInstance(Unknown Source)	at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:378)	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)	at org.apache.tomcat.dbcp.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)	at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)	... 7 moreCaused by: java.net.ConnectException: Connection refused: connect	at java.net.PlainSocketImpl.socketConnect(Native Method)	at java.net.PlainSocketImpl.doConnect(Unknown Source)	at java.net.PlainSocketImpl.connectToAddress(Unknown Source)	at java.net.PlainSocketImpl.connect(Unknown Source)	at java.net.SocksSocketImpl.connect(Unknown Source)	at java.net.Socket.connect(Unknown Source)	at java.net.Socket.connect(Unknown Source)	at java.net.Socket.(Unknown Source)	at java.net.Socket.(Unknown Source)	at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:254)	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:295)	... 23 more2012-2-19 15:35:27 edu.gzucm.yjsglxt.base.util.InitInfoUtil 严重: nullorg.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Communications link failureThe last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)	at edu.gzucm.yjsglxt.base.util.DataSourceUtil.getConnection(DataSourceUtil.java:67)	at edu.gzucm.yjsglxt.base.util.InitInfoUtil.(InitInfoUtil.java:265)	at edu.gzucm.yjsglxt.base.filter.PrepareFilter.init(PrepareFilter.java:116)	at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:273)	at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:254)	at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:372)	at org.apache.catalina.core.ApplicationFilterConfig.(ApplicationFilterConfig.java:98)	at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4584)	at org.apache.catalina.core.StandardContext$2.call(StandardContext.java:5262)	at org.apache.catalina.core.StandardContext$2.call(StandardContext.java:5257)	at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)	at java.util.concurrent.FutureTask.run(Unknown Source)	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)	at java.lang.Thread.run(Unknown Source)Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failureThe last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)	at java.lang.reflect.Constructor.newInstance(Unknown Source)	at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)	at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:346)	at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2334)	at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2371)	at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2163)	at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:794)	at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:47)	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)	at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)	at java.lang.reflect.Constructor.newInstance(Unknown Source)	at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)	at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:378)	at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)	at org.apache.tomcat.dbcp.dbcp.DriverConnectionFactory.createConnection(DriverConnectionFactory.java:38)	at org.apache.tomcat.dbcp.dbcp.PoolableConnectionFactory.makeObject(PoolableConnectionFactory.java:582)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.validateConnectionFactory(BasicDataSource.java:1556)	at org.apache.tomcat.dbcp.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1545)	... 17 moreCaused by: java.net.ConnectException: Connection refused: connect	at java.net.PlainSocketImpl.socketConnect(Native Method)	at java.net.PlainSocketImpl.doConnect(Unknown Source)	at java.net.PlainSocketImpl.connectToAddress(Unknown Source)	at java.net.PlainSocketImpl.connect(Unknown Source)	at java.net.SocksSocketImpl.connect(Unknown Source)	at java.net.Socket.connect(Unknown Source)	at java.net.Socket.connect(Unknown Source)	at java.net.Socket.(Unknown Source)	at java.net.Socket.(Unknown Source)	at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:254)	at com.mysql.jdbc.MysqlIO.(MysqlIO.java:295)	... 33 more2012-2-19 15:35:27 org.apache.coyote.AbstractProtocol start信息: Starting ProtocolHandler ["http-bio-8080"]2012-2-19 15:35:27 org.apache.coyote.AbstractProtocol start信息: Starting ProtocolHandler ["ajp-bio-8009"]2012-2-19 15:35:27 org.apache.catalina.startup.Catalina start信息: Server startup in 2983 ms

我知道是连接数据库的时候出现了错误，我检查了我的tomcat的配置文件context.xml文件

配置如下：

 1 
 2 
18 
19     
20     WEB-INF/web.xml
21 
22     
23     
26 
27     
29     
32      33      driverClassName="com.mysql.jdbc.Driver" 
34      maxActive="100" 
35      maxIdle="30" 
36      maxWait="10000" 
37      name="jdbc/mysql" 
38      password="root" 
39      type="javax.sql.DataSource" 
40      url="jdbc:mysql:///yjsglxt?characterEncoding=UTF-8" 
41      username="root"/>
42 

查了一下，才发现原来是url这里有问题：

1 url="jdbc:mysql:///yjsglxt?characterEncoding=UTF-8" 

应该改成：

1 url="jdbc:mysql://localhost:3306/yjsglxt?characterEncoding=UTF-8" 

这样做了以后，再次运行一下项目，嘿嘿，可以了……………………