I will add more when I stumble upon commands I can’t remember the syntax of.

To list all stored procedures:

mysql> SHOW PROCEDURE STATUS;

Example output (with cropped dates and times for readable table):

Db	Name	Type	Definer	Modified	Created	Security_type	Comment
mydb	store_user	PROCEDURE	root	2007-0..	2007-0..	DEFINER
mydb	store_cart	PROCEDURE	root	2007-0..	2007-0..	DEFINER
mydb	store_settings	PROCEDURE	root	2007-0..	2007-0..	DEFINER

To create a new procedure

mysql> DELIMITER $$
mysql> CREATE PROCEDURE adduser(IN username VARCHAR(32), IN emailaddress VARCHAR(32))
BEGIN
  INSERT INTO users VALUES (username, emailaddress);
END
$$

To show a stored procedure

mysql> SHOW CREATE PROCEDURE `userdb`.`adduser`\\G

Example output:

*************************** 1. row ***************************
       Procedure: adduser
        sql_mode:
Create Procedure: CREATE DEFINER=`root`@`localhost` PROCEDURE `adduser`(IN username varchar(32), IN emailaddress(32))
BEGIN
  INSERT INTO users VALUES (username, emailaddress);
END
1 row in set (0.00 sec)

To call a stored procedure from Java

Connection con = DriverManager.getConnection(url, user, password);
CallableStatement statement = con.prepareCall(\"{call userdb.adduser(?, ?)}\");
int i = 0;
statement.setString(i++, \"myuser\");
statement.setString(i++, \"myuser@spammealot.com\");
statement.execute();

For this to work you must give the user SELECT privilige to the proc table in the mysql database, where the stored procedures are stored. Do it like this:

GRANT SELECT ON `mysql`.`proc` TO \'mysqluser\'@\'myhost\';