port number of database produce error message - jdbc

Question

I'm writing a simple java program (Jcreator as my IDE) to connect with Oracle Database (using SQL Plus / Oracle 10g). I first downloaded the jar file and copied it into bin directory in oracle directory. Then, I added the jar file to my JDK and wrote this code :
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con=DriverManager.getConnection(
"jdbc:oracle:thin:#localhost:1521:amani","system","a123");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select * from emp");
while(rs.next())
System.out.println(rs.getInt(1)+" - "+ rs.getString(2)+" - "+rs.getInt(3)+"\n");
The problem is when I use the default port number 1521, I do not get any results and no error messages appear.
and I know that I'm supposed to use my own database port number which is 1158, but then I get
java.sql.SQLException: Io exception: Bad packet type
What am I doing wrong, can someone help?

Answer 1

I don't know Java so - the following might be irrelevant nonsense so I apologize if that's the case.
Anyway, shortly: 1521 is most probably the port you should use (not 1158). Credentials you provided (username = system, password = a123) are wrong; use username = scott, password = tiger instead
A longer version of the above statement: you should have access to the database; seeing your code, it is installed on your own computer. Is it up and running, i.e. can you connect to it via SQL*Plus?
Saying that you are
supposed to use my own database port number which is 1158
well, I doubt that. If you installed everything by default, then your database port number is 1521, while 1158 is reserved for OEM (Oracle Enterprise Manager database console) so I don't think that 1158 is what you should use. See Managing Oracle Database Port Numbers.
Furthermore, is your database name really "amani"? That's what this
"jdbc:oracle:thin:#localhost:1521:amani","system","a123"
-----
this
suggests. In order to get its port, TNSPING it using command prompt (I've removed unnecessary part of the output): I can't tnsping amani (obviously, I don't have access to it)
c:\Temp>tnsping amani
TNS-03505: Failed to resolve name
but I can tnsping my own XE database:
c:\Temp>tnsping xe
Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = my-laptop)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = XE)))
OK (110 msec)
See? It is "OK", and its port is 1521. Do it on your computer in order to find that information.
Finally, username and password: you used one of special, most powerful users in your database, SYSTEM (another one is SYS). It doesn't contain the EMP table - it belongs to user SCOTT (whose default password is TIGER).
As you're on Oracle 10g, if I remember well, SCOTT is one of pre-installed schemas so you should be able to connect to it. Check it as following: on my XE, I'm connected as SYS:
SQL> select username, account_status from dba_users;
USERNAME ACCOUNT_STATUS
------------------------------ --------------------------------
SYS OPEN
SYSTEM OPEN
ANONYMOUS OPEN
SCOTT LOCKED
HR OPEN
<snip>
SQL> alter user scott account unlock;
User altered.
SQL> alter user scott identified by tiger;
User altered.
SQL> connect scott/tiger#xe
Connected.
SQL> select count(*) From emp;
COUNT(*)
----------
12
SQL>
I hope you understood what I did.
That much about Oracle part of the story; I really wouldn't know what to do if that doesn't help, in order to make your Java side work. Hopefully, someone else will be able to assist.