CannotcreatePoolableConnectionFactory (Communicationslink_MySQL

CannotcreatePoolableConnectionFactory (Communicationslinkfailure) -- Connectionrefused: connect bitsCN.com

Today, when I was working on a web project, I encountered such an exception:

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 attached ed any packets from the server .) at edu.gz ucm. yjsglxt. base. util. timeSetUtils. getTimeSets (TimeSetUtils. java: 52) at edu.gz ucm. 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 attached ed 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.gz ucm. 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 attached ed 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: connectat 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.gz ucm. yjsglxt. base. util. InitInfoUtil
        
          Severe: 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 attached ed 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.gz ucm. yjsglxt. base. util. dataSourceUtil. getConnection (performanceutil. java: 67) at edu.gz ucm. yjsglxt. base. util. initInfoUtil.
         
           (InitInfoUtil. java: 265) at edu.gz ucm. 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 attached ed 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: connectat 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 Information: Starting ProtocolHandler ["http-bio-8080"] 15:35:27 org. apache. coyote. abstractProtocol start Information: Starting ProtocolHandler ["ajp-bio-8009"] 15:35:27 org. apache. catalina. startup. catalina start Information: Server startup in 2983 MS
                
               
              
             
            
           
          
         
        
       
      
     
    
   
  
 

I know an error occurred while connecting to the database. I checked the context. xml file of my tomcat configuration file.

The configuration is as follows:

 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 
 

After checking this information, we found that the original url has a problem:

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

It should be changed:

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

After doing so, run the project again ........................

BitsCN.com