Using MysqlConnectionPoolDataSource with a load-balanced URL generated exceptions of type ClassCastException:

ClassCastException in MysqlConnectionPoolDataSource
Caused by: java.lang.ClassCastException: $Proxy0
   at
com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource.getPooledConnection(MysqlConne
ctionPoolDataSource.java:80)

java.lang.ClassCastException: $Proxy2
 at com.mysql.jdbc.jdbc2.optional.StatementWrapper.executeQuery(StatementWrapper.java:744)

(Bug#48486)

The implementation for load-balanced Connection used a proxy, which delegated method calls, including equals() and hashCode(), to underlying Connection objects. This meant that successive calls to hashCode() on the same object potentially returned different values, if the proxy state had changed such that it was utilizing a different underlying connection. (Bug#48442)

The batch rewrite functionality attempted to identify the start of the VALUES list by looking for “VALUES ” (with trailing space). However, valid MySQL syntax allows for VALUES to be followed by whitespace or an opening parenthesis:

INSERT INTO tbl VALUES
(1);

INSERT INTO tbl VALUES(1);

Queries written with the above formats did not therefore gain the performance benefits of the batch rewrite. (Bug#48172)

With the connection string option noDatetimeStringSync set to true, and server-side prepared statements enabled, the following exception was generated if an attempt was made to obtain, using ResultSet.getString(), a datetime value containing all zero components:

java.sql.SQLException: Value '0000-00-00' can not be represented as java.sql.Date

(Bug#32525)