We would install this Jar file in the database with the following statement. Although it has the form of a procedure call, this statement is really acting as a DDL statement. A DBMS vendor may provide a specialized JVM with its product, or it may allow the use of any JVM that supports the operating system that is being used. The classes that we have imported may contain many methods. In SQLJ Part 1, we will make direct use of only methods that are both public and static .
Static methods execute independently of any specific object instance.
Like all methods, these methods may return values of some data type or they may be void. A decision that could have been made would have been to create new SQL statements to invoke these methods. Instead, the decision was made to provide a mapping from SQL routines to Java methods. In that way an application can invoke these routines in exactly the same way that it would invoke SQL's other types of routines. A Java routine is a routine that has a mapping to a Java method that provides its implementation.