JDBC 连接MySQL 问题

今天用mm.mysql-2.0.4-bin.jar连接mysql，报错如下：

Communication failure during handshake. Is there a server running on localhost:3306?

我的Mysql数据库的版本：5.0.18。使用mm.mysql-2.0.4-bin.jar，。出现了上面的问题。mysql服务是开的，有可能是驱动不行了，上mysql下载了个对应5.0的版本：mysql-connector-java-5.0.8-bin.jar ，再连接，ok，没有出错。

drivers=org.gjt.mm.mysql.Driver poolapp.url=jdbc:mysql://localhost/test?user=root&password=ffcsoss&useUnicode=true&characterEncoding=8859_1

ysql网站上的说明：

MySQL Connector/J is a JDBC Type 4 driver. Different versions are available that are compatible with the JDBC-3.0 and JDBC-4.0 specifications. The Type 4 designation means that the driver is pure-Java implementation of the MySQL protocol and does not rely on the MySQL client libraries.