没有找到合适的连接池驱动程序

Question

我有一个play 2.1应用程序，我正在使用junit进行单元测试。我的测试运行良好，并且能够执行他们的数据库操作。显然驱动程序（org.postgresql.Driver）已加载。

但是，在测试之间，看起来连接池无法访问驱动程序。以下是我日志中典型序列的摘录。有谁知道为什么连接池在应用程序没问题时可能无法访问驱动程序？

[info] application - QuickWitness Server shutdown... 
[error] c.j.b.h.AbstractConnectionHook - Failed to acquire connection Sleeping for 1000ms and trying again. Attempts left: 10. Exception: null 
[error] c.j.b.ConnectionHandle - Database access problem. Killing off all remaining connections in the connection pool. SQL State = 08001 
[error] c.j.b.PoolWatchThread - Error in trying to obtain a connection. Retrying in 1000ms 
java.sql.SQLException: No suitable driver found for jdbc:postgresql:qw 
     at java.sql.DriverManager.getConnection(DriverManager.java:602) ~[na:1.6.0_26] 
     at java.sql.DriverManager.getConnection(DriverManager.java:185) ~[na:1.6.0_26] 
     at com.jolbox.bonecp.BoneCP.obtainRawInternalConnection(BoneCP.java:256) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.ConnectionHandle.obtainInternalConnection(ConnectionHandle.java:211) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.ConnectionHandle.<init>(ConnectionHandle.java:170) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.PoolWatchThread.fillConnections(PoolWatchThread.java:101) [bonecp.jar:0.7.1.RELEASE] 
[info] application - QuickWitness Server has started 
[debug] application - entering ensureTriggersAndStoredProceduresAreInstalled() 
[debug] application - exiting ensureTriggersAndStoredProceduresAreInstalled() 
[info] application - logging initialized 
[info] application - Register user request from localhost:12345 
[info] application - QuickWitness Server shutdown... 
[error] c.j.b.h.AbstractConnectionHook - Failed to acquire connection Sleeping for 1000ms and trying again. Attempts left: 10. Exception: null 
[error] c.j.b.ConnectionHandle - Database access problem. Killing off all remaining connections in the connection pool. SQL State = 08001 
[error] c.j.b.PoolWatchThread - Error in trying to obtain a connection. Retrying in 1000ms 
java.sql.SQLException: No suitable driver found for jdbc:postgresql:qw 
     at java.sql.DriverManager.getConnection(DriverManager.java:602) ~[na:1.6.0_26] 
     at java.sql.DriverManager.getConnection(DriverManager.java:185) ~[na:1.6.0_26] 
     at com.jolbox.bonecp.BoneCP.obtainRawInternalConnection(BoneCP.java:256) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.ConnectionHandle.obtainInternalConnection(ConnectionHandle.java:211) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.ConnectionHandle.<init>(ConnectionHandle.java:170) ~[bonecp.jar:0.7.1.RELEASE] 
     at com.jolbox.bonecp.PoolWatchThread.fillConnections(PoolWatchThread.java:101) [bonecp.jar:0.7.1.RELEASE] 
[info] application - QuickWitness Server has started 

Answer 1

我有同样的问题。就我而言，问题发生是因为没有足够的数据库连接。看起来这场比赛不会在封闭结束时关闭连线。这些文件告诉我们另一个故事，或许这是一个错误？

解决方案1：你可以增加你的连接在你的application.conf，通过改变 （http://www.playframework.com/documentation/2.1.0/SettingsJDBC）

db.default.partitionCount=2 
db.default.maxConnectionsPerPartition=5 
db.default.minConnectionsPerPartition=5 

解决方案2：你可以使用后关闭连接（http://www.playframework.com/documentation/2.0/ScalaDatabase）

DB.withConnection { conn => 
    // do whatever you need with the connection 
    conn.close() 
} 

Answer 2

我假设你已经在/ Project/lib文件夹中放置了正确需要的驱动程序

1）检查dat在application.conf中配置url配置。

2）添加 “evolutionplugin =禁用” 在application.conf

3）请参阅http://digitalsanctum.com/2012/05/30/play-framework-2-tutorial-database-access/，你添加的build.scala依赖？

谢谢，希望能帮到~~

Answer 3

我和squeryl有同样的问题。看起来我的代码没有问题。我认为这是会发生的事情：由于单元测试我的应用程序被连续多次启动和停止。 Play在停止应用程序时关闭连接。但是，如果您的机器足够快，它可以在应用程序启动时请求新的连接，然后才能关闭上次运行中使用的连接。这只是一个时间问题。你可以通过增加数据库连接的最大数量，或者在Global's onStop结束时暂时休眠一段时间来解决它。