JDBC链接ORACLE的问题

代码如下：
package cn.com.sony.newsis.sell.action;
import java.sql.*;
public class UpdateDB 
{
public static void main(String[] args) 
{
String url ="jdbc:oracle:thin:@localhost:1521:report AS SYSDBA";
String userName="report";
String passWord="report";
Connection con=null;
Statement stmt=null;
ResultSet rs=null;

try{
Class.forName("oracle.jdbc.OracleDriver");
}catch(Exception e){
System.out.println("无法装载驱动");
}

try{
con=DriverManager.getConnection(url,userName,passWord);
stmt=con.createStatement(); rs=stmt.executeQuery("select * from T_ML_SYS");
while(rs.next()){
String userId=rs.getString("user_id");
                        System.out.println("userId==="+userId); }
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
if(rs!=null)
rs.close();
}catch(SQLException e1){
System.out.println("SQL_State=="+e1.getSQLState());
System.out.println("错误代码:"+e1.getErrorCode());
System.out.println("错误情况的字符串"+e1.toString());
}

try{
if(stmt!=null)
stmt.close();
}catch(SQLException e2){
System.out.println("SQL_state="+e2.getSQLState());
System.out.println("错误代码:"+e2.getErrorCode());
System.out.println("错误情况的字符串:"+e2.toString());
}

try{
if(con!=null)
stmt.close();
}catch(SQLException e3){
System.out.println("SQL_state="+e3.getSQLState());
System.out.println("错误代码:"+e3.getErrorCode());
System.out.println("错误情况的字符串:"+e3.toString());
}
}
}
}
运行后报错：
java.sql.SQLException: Io 异常: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=153092352)(ERR=12505)(ERROR_STACK=(ERROR=(CODE=12505)(EMFI=4))))
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:334)
at oracle.jdbc.ttc7.TTC7Protocol.handleIOException(TTC7Protocol.java:3664)
at oracle.jdbc.ttc7.TTC7Protocol.logon(TTC7Protocol.java:353)
at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:371)
at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:551)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:351)
at java.sql.DriverManager.getConnection(DriverManager.java:539)
at java.sql.DriverManager.getConnection(DriverManager.java:189)
at cn.com.sony.newsis.sell.action.UpdateDB.main(UpdateDB.java:24)
出现的问题如何解决？请高手指点下