22.7.1 Longname: Converting Java Long Names

Java class andmethod names can easily exceed the maximum SQL identifier length of 30 characters. In such cases, Oracle creates a unique "short name" for the Java code element and uses that name for SQL- and PL/SQL-related access.

Use the following function to obtain the full (long) name for a given short name:

FUNCTION DBMS_JAVA.LONGNAME (shortname VARCHAR2) RETURN VARCHAR2

The following query displays the long names for all Java classes defined in the currently connected schema for which the long names and short names do not match:

/* File on web: longname.sql */

SELECT object_name shortname,

DBMS_JAVA.LONGNAME (object_name) longname

FROM USER_OBJECTS

WHERE object_type = 'JAVA CLASS'

AND object_name != DBMS_JAVA.LONGNAME (object_name);

This query is also available inside the myJava package (found in the myJava.pkg file); its use is shown here. Suppose that I define a class with this name:

public class DropAnyObjectIdentifiedByTypeAndName {

That is too long for Oracle, and we can verify that Oracle creates its own short name as follows:

SQL> exec myJava.showlongnames

Short Name | Long Name

----------------------------------------------------

Short: /247421b0_DropAnyObjectIdentif

Long: DropAnyObjectIdentifiedByTypeAndName

22.7.2 Get_, set_, and reset_compiler_option: Getting and Setting Compiler Options

You can also set compiler option values in the database table JAVA$OPTIONS (called the options table from here on). Then, you can selectively override those settings using loadjava command-line options. A row in the options table contains the names of source schema objects to which an option setting applies. You can use multiple rows to set the options differently for different source schema objects.

The compiler looks up options in the options table unless they are specified on the loadjava command line. If there is no options-table entry or command-line value for an option, the compiler uses the following default values (you can find more information about nondefault values in Oracle's SQLJDeveloper'sGuideandReference documentation):

encoding = latin1

online = true // applies only to SQLJ source files

You can get and set options-table entries using the following DBMS_ JAVA functions and procedures:

FUNCTION DBMS_JAVA.GET_COMPILER_OPTION (

what VARCHAR2, optionName VARCHAR2)

PROCEDURE DBMS_JAVA.SET_COMPILER_OPTION (

what VARCHAR2, optionName VARCHAR2, value VARCHAR2)

PROCEDURE DBMS_JAVA.RESET_COMPILER_OPTION (

what VARCHAR2, optionName VARCHAR2)

The parameter what is the name of a Java package, the full name of a class, or the empty string. After searching the options table, the compiler selects the row in which what most closely matches the full name of the schema object. If what is the empty string, it matches the name of any schema object.

optionName is the name of the option being set. Initially, a schema does not have an options table. To create one, use the procedure DBMS_ JAVA.SET_COMPILER_OPTION to set a value. The procedure creates the table if it does not exist. Enclose parameters in single quotes, as shown in the following example:

SQL> DBMS_JAVA.SET_COMPILER_OPTION ('X.sqlj', 'online', 'false');