java Eclipse MySQL求助 有点乱~

import java.sql.*;
public class DataBaseOperation{
private Connection conn;
public DataBaseOperation()throws  ClassNotFoundException,SQLException{
Class.forName("com.mysql.jdbc.Driver");
conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/wash"
,"root","890120");
}
public String getDBAbout() throws SQLException{
String message="";
DatabaseMetaData dbmdData=this.conn.getMetaData();
message=dbmdData.getDriverName()+"name"+dbmdData.getDriverVersion();
return message;
}
public static void main(String[]args)throws  ClassNotFoundException,SQLException{
DataBaseOperation dbo=new DataBaseOperation();
System.out.println(dbo.getDBAbout());
}
}
这段代码在dos下运行正常，而在Eclipse下不能运行时怎么回事，是我的Eclipse有问题吗？
请大虾指导小弟，刚刚接触连接数据库~~愁~~~~~~~
小弟不胜感激！！
在Eclipse下出错提示 ：
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Laun