Question

我已将服务器MySQL数据库更改为使用utf8mb4，因为我们需要支持表情符号。我遵循了基于Mathias Bynens的How to support full Unicode in MySQL databases文章的说明。唯一的区别是我没有从utf8改变。

以下是配置：

[client]
default-character-set = utf8mb4

[mysql]
default-character-set = utf8mb4

[mysqld]
character-set-client-handshake = FALSE
init-connect = 'SET NAMES utf8mb4'
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci

这是MySQL SHOW VARIABLES输出：

mysql> SHOW VARIABLES WHERE Variable_name LIKE 'character\_set\_%' OR Variable_name LIKE 'collation%';
+--------------------------+--------------------+
| Variable_name            | Value              |
+--------------------------+--------------------+
| character_set_client     | utf8mb4            |
| character_set_connection | utf8mb4            |
| character_set_database   | utf8mb4            |
| character_set_filesystem | binary             |
| character_set_results    | utf8mb4            |
| character_set_server     | utf8mb4            |
| character_set_system     | utf8               |
| collation_connection     | utf8mb4_unicode_ci |
| collation_database       | utf8mb4_unicode_ci |
| collation_server         | utf8mb4_unicode_ci |
+--------------------------+--------------------+
10 rows in set (0.00 sec)

重新启动MySQL＆amp;我的应用程序，控制台打印错误日志如下：

2014-08-05 17:33:49,022 [com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2] WARN  com.mchange.v2.resourcepool.BasicResourcePool - com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@6ae03500 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
java.sql.SQLException: Unknown character set index for field '224' received from server.
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:910)
    at com.mysql.jdbc.Connection.getCharsetNameForIndex(Connection.java:3556)
    at com.mysql.jdbc.Field.<init>(Field.java:192)
    at com.mysql.jdbc.MysqlIO.unpackField(MysqlIO.java:731)
    at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:387)
    at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:2076)
    at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:1451)
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1787)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3277)
    at com.mysql.jdbc.Connection.execSQL(Connection.java:3206)
    at com.mysql.jdbc.Statement.executeQuery(Statement.java:1232)
    at com.mysql.jdbc.Connection.loadServerVariables(Connection.java:4478)
    at com.mysql.jdbc.Connection.initializePropsFromServer(Connection.java:4062)
    at com.mysql.jdbc.Connection.createNewIO(Connection.java:2789)
    at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Aug 5, 2014 5:33:49 PM org.hibernate.util.JDBCExceptionReporter logExceptions
WARNING: SQL Error: 0, SQLState: null
Aug 5, 2014 5:33:49 PM org.hibernate.util.JDBCExceptionReporter logExceptions
SEVERE: Connections could not be acquired from the underlying database!
Aug 5, 2014 5:33:49 PM org.hibernate.util.JDBCExceptionReporter logExceptions
WARNING: SQL Error: 0, SQLState: null
Aug 5, 2014 5:33:49 PM org.hibernate.util.JDBCExceptionReporter logExceptions
SEVERE: Connections could not be acquired from the underlying database!

登录我的CMS或API调用无法正常工作。它给了我上述错误，我无法解决任何解决方案。

下一步该怎么做才能解决错误？

Answer 1

我也在那里，我通过简单地将连接器升级到"mysql-connector-java-5.1.30-bin.jar"来修复它。希望它会有所帮助。

从https://dev.mysql.com/downloads/connector/j/

下载最新的连接器

MySQL更改为utf8mb4后，从服务器收到字段'224'的错误未知字符集索引

1 个答案: