Java連接池出現BoneCP STRANGE錯誤

Question

我是Java編程的新手，正在嘗試學習。

我有一個數據庫mysql，並管理與連接池的連接，BoneCP是我使用的庫。

創建池的代碼是這樣的：

        BoneCPConfig config = new BoneCPConfig();                                      // create a new configuration object
        config.setJdbcUrl(  R.database.url + R.database.dbName );                      // set the JDBC url
        config.setUsername( R.database.userName );                                     // set the username
        config.setPassword( R.database.password );                                     // set the password

        config.setMinConnectionsPerPartition(2);
        config.setMaxConnectionsPerPartition(5);
        config.setPartitionCount( 3 );


        try{

            connectionPool = new BoneCP( config );                                     // setup the connection pool

        }catch( Exception e ){

            System.out.println( e );

        }

當我需要用於向數據庫發送查詢的連接時，我使用以下代碼行捕獲了連接：conn = R.database.connectionPool.getConnection（）;

我認為目前還可以，並且沒有任何錯誤。

一分鍾后，控制台會說：

     [BoneCP-pool-watch-thread] ERROR com.jolbox.bonecp.BoneCP - Failed to acquire connection to jdbc:mysql://localhost:3306/test_db. Sleeping for 7000 ms. Attempts left: 0
     java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost:3306/test_db
at java.sql.DriverManager.getConnection(DriverManager.java:596)
at java.sql.DriverManager.getConnection(DriverManager.java:215)
at com.jolbox.bonecp.BoneCP.obtainRawInternalConnection(BoneCP.java:363)
at com.jolbox.bonecp.BoneCP.obtainInternalConnection(BoneCP.java:269)
at com.jolbox.bonecp.ConnectionHandle.<init>(ConnectionHandle.java:242)
at com.jolbox.bonecp.PoolWatchThread.fillConnections(PoolWatchThread.java:115)
at com.jolbox.bonecp.PoolWatchThread.run(PoolWatchThread.java:82)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)



  [BoneCP-pool-watch-thread] ERROR com.jolbox.bonecp.CustomThreadFactory - Uncaught Exception in thread BoneCP-pool-watch-thread
  java.lang.NoClassDefFoundError: com/jolbox/bonecp/hooks/ConnectionState
at com.jolbox.bonecp.ConnectionHandle.markPossiblyBroken(ConnectionHandle.java:382)
at com.jolbox.bonecp.ConnectionHandle.<init>(ConnectionHandle.java:244)
at com.jolbox.bonecp.PoolWatchThread.fillConnections(PoolWatchThread.java:115)
at com.jolbox.bonecp.PoolWatchThread.run(PoolWatchThread.java:82)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)

這是一個奇怪的問題！

非常感謝！！

Answer 1

No suitable driver found for jdbc:mysql://localhost:3306/test_db

這似乎暗示您在類路徑上沒有Java MySQL JDBC驅動程序，請查看MySQL可用的連接器，並確保在類路徑上包含相應驅動程序的JAR。

MySQL連接器