Grails的錯誤，同時連接MySQL的

Question

我得到同時連接到MySQL

我已經在我的應用程序複製使用mysql-connector-java的5.1.22-bin.jar到lib文件夾下面的錯誤

| Error 2012-11-26 16:14:16,981 [localhost-startStop-1] ERROR context.GrailsContextLoader - Error executing bootstraps: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
Message: Error creating bean with name 'transactionManagerPostProcessor': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
    Line | Method 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by BeanCreationException: Error creating bean with name 'sessionFactory': Cannot resolve reference to bean 'hibernateProperties' while setting bean property 'hibernateProperties'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by BeanCreationException: Error creating bean with name 'hibernateProperties': Cannot resolve reference to bean 'dialectDetector' while setting bean property 'properties' with key [hibernate.dialect]; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by BeanCreationException: Error creating bean with name 'dialectDetector': Invocation of init method failed; nested exception is org.springframework.jdbc.support.MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by MetaDataAccessException: Error while extracting DatabaseMetaData; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 334 | innerRun in java.util.concurrent.FutureTask$Sync 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Caused by SQLNestedException: Cannot load JDBC driver class 'com.mysql.jdbc.Driver' 
->> 1429 | createConnectionFactory in org.apache.commons.dbcp.BasicDataSource 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 1371 | createDataSource in  '' 
| 1044 | getConnection in  '' 
| 334 | innerRun in java.util.concurrent.FutureTask$Sync 
| 166 | run . . . in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run  in java.lang.Thread 

Caused by ClassNotFoundException: com.mysql.jdbc.Driver 
->> 366 | run  in java.net.URLClassLoader$1 
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
| 355 | run  in  '' 
| 354 | findClass in java.net.URLClassLoader 
| 423 | loadClass in java.lang.ClassLoader 
| 356 | loadClass in  '' 
| 1420 | createConnectionFactory in org.apache.commons.dbcp.BasicDataSource 
| 1371 | createDataSource in  '' 
| 1044 | getConnection in  '' 
| 334 | innerRun in java.util.concurrent.FutureTask$Sync 
| 166 | run  in java.util.concurrent.FutureTask 
| 1110 | runWorker in java.util.concurrent.ThreadPoolExecutor 
| 603 | run  in java.util.concurrent.ThreadPoolExecutor$Worker 
^ 722 | run . . . in java.lang.Thread 

Answer 1

當它在Maven存儲庫中可用時，不應該將jar文件複製到lib目錄中 - 最好下載一次並緩存它，而不是在每個項目中都有一個副本。實際上，MySQL驅動程序就是我們在生成的BuildConfig.groovy中使用的示例。只需取消註釋並更新版本：

dependencies { 
    runtime 'mysql:mysql-connector-java:5.1.22' 
} 

如果您確實有一個不在Maven倉庫中的jar文件，請將其放入您的lib目錄中。但Grails不會自動發現它，因此您需要運行grails compile --refresh-dependencies