Erro ao efetuar a conexao com o oracle 7

package jp.com.test;

import java.sql.*;


public class JdbcTest {
	public static void main(String args[]) throws SQLException {
		DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
		Connection conn = DriverManager.getConnection(
				"jdbc:oracle:thin:@myhost:1521:orcl", "user", "pass");
		Statement stmt = conn.createStatement();
		ResultSet rset = stmt.executeQuery("select * from dual");
		while (rset.next())
			System.out.println("sql: " + rset.getString(1));
	}
}

Exception in thread "main" java.sql.SQLException: Exceção de E/S: End of TNS data channel
	at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
	at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
	at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:255)
	at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
	at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414)
	at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
	at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
	at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
	at java.sql.DriverManager.getConnection(Unknown Source)
	at java.sql.DriverManager.getConnection(Unknown Source)
	at jp.com.test.JdbcTest.main(JdbcTest.java:11)

alias.world = 
  (DESCRIPTION = 
    (ADDRESS_LIST = 
        (ADDRESS = 
          (COMMUNITY = tcp.world)
          (PROTOCOL = TCP)
          (Host = myhost)
          (Port = 1521)
        )
        (ADDRESS = 
          (COMMUNITY = tcp.world)
          (PROTOCOL = TCP)
          (Host = myhost)
          (Port = 1526)
        )
    )
    (CONNECT_DATA = (SID = ORCL)
    )
  )

ORA-03134: As conexões com este servidor não são mais suportadas