java程序链接数据库失败


import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.Connection;public class DBtest {
public static void main(String[] args) throws Exception{
Connection conn=null;
Statement  st=null;
ResultSet rs=null;

Class.forName("oracle.jdbc.driver.OracleDriver");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1158:emp", "scott", "********");//这里密码我用*代替 
st=conn.createStatement();
rs=st.executeQuery("select * from emp");
while(rs.next())
{
System.out.println("empno:"+rs.getInt(1)+",ename:"+rs.getString(2)+",job:"+rs.getString(3));

}
rs.close();
st.close();
conn.close();
}}
jdbc 驱动包 ojbdc6.jar下面是报错：Exception in thread "main" java.sql.SQLException: Got minus one from a read call
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:531)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:221)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at DBtest.main(DBtest.java:13)
Caused by: oracle.net.ns.NetException: Got minus one from a read call
at oracle.net.ns.Packet.receive(Packet.java:285)
at oracle.net.ns.NSProtocol.connect(NSProtocol.java:286)
at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301)
... 7 more链接不了 求大神打救