java连接数据库问题

我在Struts程序连接数据库，测试的时候报错，如下：
com.microsoft.sqlserver.jdbc.SQLServerException: 用户 'sa' 登录失败。
at com.microsoft.sqlserver.jdbc.SQLServerException.makefromDatabaseError(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSTokenHandler.onEOF(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSParser.parse(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.sendLogon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.logon(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.access$000(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection$LogonCommand.doExecute(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.loginWithoutFailover(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at org.login.conn.DBConnection.getConn(DBConnection.java:24)
at org.login.conn.DBConnection.execuQuery(DBConnection.java:68)
at org.login.daoimpl.PersonDAOImpl.isLogin(PersonDAOImpl.java:17)
at org.login.struts