Code Generation

Introduction

This section explains:

How to select the classes to generate or verify
Setting up EJB preferences
Selecting where the generated files are output
How to verify Classes
How to generate the selected classes
How to use the generated classes

Code Generation Tabs

To display the code generation options, the last entry in the tree on the left hand side of the window should be selected.

Selecting The Classes To Generate Or Verify

The Code Generation uses the following tab set:

Java Sources Root Folder: Use this button to popup Swing's File selection dialog. Select the folder (do not open it) which is the root of your project files. The wizard will create any subfolders to match any packages you have specified for your Java classes.
Available Classes This "multiple selection" list box shows all the classes currently not scheduled for generation. Select those that you would like to generate, then press the arrow button
Use These "multiple selection" list box shows all the classes currently scheduled for generation. Select those that you would not like to generate or verify, then press the arrow button
Arrow Buttons allow you to earmark classes for code generation, or no code generation

EJB Setup

The EJB Setup tab contains settings which affect all the generated BMP EJB's.

Datasource JNDI name specifies the datasource the implementation ejb's should use. This information is usually in the EJB container.
DataSource <res-ref-name> is used in the generated manifest. Each ejb is declared to use the datasource resource reference.
Do not Generate Transactions determines if the manifest contains transaction information.
Override Bean Transactions can set the transactions for all the generated beans' home interface methods, and remote interface methods.
Generate Bean Transactions causes the wizard to generate many transaction entries, in the manifest file. One entry per bean method is generated (including property get and set methods)
Save saves all changes made on this tab.

Specifying The Code Style

This tab allows the style of the code generated to be specified. If any changes are made to the fields, the Save button should be pressed.

Brace radio buttons are used to specify how the generated Java code should place the opening braces '{' in the code
Tab as Tab determines if a tab character or spaces should be used to indent the code.
Tab Length is used if spaces are selected to indent the code, this field specifies the number of spaces each indentation should be.
Save, the Save button should be pressed to save all changes made.

Specifying The File Locations

The above tab can be used to specify where the java code files should be generated.

The folder (or directory) can be selected by pressing the "..." button, or the location can be entered in the textfiled. The folder can be relative to the project file's location, or a fully qualified path (absolute path).

Verifying Classes

When coding against databases, there is the danger that the database schema has been changed. This can cause programs to stop working correctly. Finding the problem used to be tough. The wizard can check the classes against the database for you. Any possibly problematic changes are reported.

The following Warnings are issued:

99 The wizard is not connected to the database. Most problems will go undetected when disconnected.
100 The column or stored procedure parameter is new. The database object (table, view...) should be inspected, and the class viewed. This will cause the wizard to generate the new column in the class. Each class must be viewed individually to get the wizard to add the new column to each class.
101 The column has changed type in the database. The column/stored procedure parameter should be reviewed. Pressing the synchronize button causes the wizard to hold the new type. Then each class should be reviewed, to make sure the class property type is correct.
102 The column's nullable status has changed. The column/stored procedure parameter should be reviewed. Pressing the synchronize button causes the wizard to hold the new type. Then each class should be reviewed, to make sure the class property type is correct.
103 The column has been dropped from the database. The column/stored procedure parameter needs to be deleted in the wizard. Pressing the delete button causes the wizard to remove the column from the project file. Then each class should be reviewed, this causes the wizard to remove the column from the class. It is advisable to review classes' sql methods, in case they use this in the Where, Order By... clauses.
104 The column is no longer in the database, and no longer in the wizard's tree, however, the class still references the column. The class should be reviewed, this forces the wizard to remove the column from the class. It is advisable to review classes' sql methods, in case they use this in the Where, Order By... clauses.
105 the stored procedure's IN/INOUT/OUT/RETURN status has changed. The stored procedure parameter should be reviewed. Pressing the synchronize button causes the wizard to hold the new parameter type. Then each class should be reviewed, to make sure the class reflects the new access type..

The following link explains in more detail how to manage changes in the database. The use of the Synchronize and Delete buttons is discussed.

Generating The Code

To generate code, the "Generate Code" button needs to be pressed. A status is displayed to show what classes are currently being generated, and if any problems have occurred.

Anytime a file already exists, it is renamed with an extension of .xja

To see how to use the generated JDBC Classes click here.
To see how to use the generated JDBC stored procedure classes click here.
To see how to use the generated BMP EJB classes click here.