What are Unix Sockets and What Port does the database use?
=========================================================
Martin Hollyer, MySQL newbie here. I have done a number of
servlet JDBC applications with JDBC and Access.
Recently, I installed MySQL on my local Window NT computer
and have had no difficulty connecting to MySQL on my local machine.
In order to create Java Database applications, I have to know the
port number my database uses. With MySQL on my Local WinNT
machine, I type the status command:
status
mysql Ver 9.13 Distrib 3.21.13a-gamma, for Win/95 i586
Connection id: 7
Current database: hollyer
Current user: tr003073@localhost
Server version 3.21.29a-gamma-debug
Protocol version 10
Connection Localhost via TCP/ip
TCP Port 3306
Uptime: 2 hours 1 minute 1 second
Threads: 3 Questions: 673 Slow queries: 0 Opens: 76 Flush tables: 1 Open
tables: 7
--------------
This gives me the port number (3306) from a TCP/IP connection.
However, on my Internet Provider's Solaris computer, the UNIX Sockets
are given instead (/tmp/mysql.sock) with no ports specified.
mysql Ver 9.27 Distrib 3.22.13-beta, for sun-solaris2.6 (sparc)
Connection id: 289
Current database: hollyer
Current user: tr003073@localhost
Server version 3.22.13-beta
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /tmp/mysql.sock
Uptime: 9 days 6 hours 57 min 8 sec
Threads: 3 Questions: 2949 Slow queries: 0 Opens: 265 Flush tables: 1 Open
tables: 62
--------------
How do I find out to which port number I need to connect?
Do I have to use UNIX Sockets in my application code? I have
tried using /tmp/mysql.socket in my ViewDB.java application as
part of the JDBC connection but received the following error.
// force loading of the jdbc.odbc Driver
Class.forName("org.gjt.mm.mysql.Driver");
// connect to the database
mmCon = DriverManager.getConnection(
"jdbc:mysql://localhost:/tmp/mysql.sock/databaseName",
"user","pass"); // ** note /tmp/mysql/sock for Port Number
// ** obviously will give a
// ** NumberFormatException because the code
// ** is expecting a Port number instead of
// ** /tmp/mysql.sock
// create Statements
myStmt = mmCon.createStatement();
Indeed a NumberFormatException is given:
java.lang.NumberFormatException: /
at java.lang.Throwable.<init>(Compiled Code)
at java.lang.Exception.<init>(Compiled Code)
at java.lang.RuntimeException.<init>(Compiled Code)
at java.lang.IllegalArgumentException.<init>(Compiled Code)
at java.lang.NumberFormatException.<init>(Compiled Code)
at java.lang.Integer.parseInt(Compiled Code)
at java.lang.Integer.parseInt(Compiled Code)
at org.gjt.mm.mysql.Driver.port(Compiled Code)
at org.gjt.mm.mysql.Driver.connect(Compiled Code)
at java.sql.DriverManager.getConnection(Compiled Code)
at java.sql.DriverManager.getConnection(Compiled Code)
at ViewDB.<init>(Compiled Code)
at ViewDB.main(Compiled Code)
Conversely, when I substitute the default port on my Windows NT machine when trying
to get a Connection, a NullPointerException is given. Most likely because I have not
connected to the right Port.
So do I connect to the server using code like the following to establish a
port?
Socket s = new Socket("localhost/tmp/mysql.sock", 3306); //????????
Any help with the above would be greatly appreciated.
Martin Hollyer
