Java.sql.SQLException: IO Error: The Network Adapter could not establish...

Question

Hi,
I know that there are a lot of threads with this error, but I don't know how to solve my situation yet.
I'm trying to access to the database via JDBC, and the driver return the following error:
java.sql.SQLException: IO Error: The Network Adapter could not establish the connection
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:419)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:536)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:228)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:521)
at net.sourceforge.squirrel_sql.fw.sql.SQLDriverManager.getConnection(SQLDriverManager.java:133)
at net.sourceforge.squirrel_sql.client.mainframe.action.OpenConnectionCommand.execute(OpenConnectionCommand.java:97)
at net.sourceforge.squirrel_sql.client.mainframe.action.ConnectToAliasCommand$SheetHandler.run(ConnectToAliasCommand.java:281)
- My oracle database is up and I can access to it with locally with TOAD
- I can do TELNET localhost 1521 in the server that has the DB installed
- I can do a successful ping from the client computer to the oracle server
- There aren't any firewalls between the client and the server.
- When I try to do TELNET <IP Address> 1521 from the client computer to the oracle DB Server, the connection could not be opened
- I tryed to do a TELNET to another port where I have another service, and the result has been successful. So the problem is related with the port 1521...
I don't have any knowledge about database administration, so I don't know what to do to solve this.
Can you help me please?

Answer 1

java.sql.SQLException: IO Error: The Network Adapter could not establish the connectionThis preposterous error message is Oracle's way of saying either 'Connection refused' or 'Connection timeout' or 'no route to host' or 'unknown host'. However because of the stupidity of making up their own message instead of giving the original exception, it is impossible to say which. The pretentious wording is also stupid: network adapters don't create connections. TCP/IP stacks do that.
As to your problem, either there is no such host, no route to the host, nothing listening at the IP:port you specified, or there is a firewall in the way. And that includes a possible Windows firewall on the server host itself.