DODS - Basic Concepts
dods.gif (11357 bytes)The Data Object Design Studio (DODS) lets you design the data-layer classes of an application that uses the Enhydra Application Framework. You can then use DODS to generate and compile the Java source code for these data-layer classes.

Running DODS

To run DODS, simply invoke it in your build.xml like this:

<taskdef name="dods_gen" classname="org.enhydra.dods.taskdefs.DodsGenerator"
	classpathref="build.gen.classpath" />
<dods_gen doml="${src.gen.dir}/discRack.doml"
    vendor="Standard" 
    enhydraversion="enhydra3" 
    jdbcversion="jdbc1" 
    showdetail="true"    
    sourceout="${src.gen.dir}"
    srcdir="${src.gen.dir}"
    destdir="${build.classes.dir}"
    includes="**/*.java"
    excludes="**/old**/**"
    debug="${build.debug}"
    optimize="${build.optimize}"
    deprecation="${build.deprecation}"
    verbose="${build.verbose}"
/>

When you run Ant, this will invoke the DodsGenerator taskdef, which will automatically invoke DODS to generate the necessary files and then compile them for you too.


What's new in DODS 4.0?

DODS has a new user interface.

DODS converts Enhydra 3 DOML files to the new Enhydra 4 DOML format. When you open an Enhydra 3 DOML file, the editor saves a back up copy with a .dods3 extension.

Old and new DODS terminology:

DODS3 DOML Term DODS3 UI Term DODS4 Term
database database vendor
package package package
table data object class
column attribute field

Adding packages

To add packages:

  1. Select the doml entry, then right-click and choose package from the Add menu or choose the Insert | package menu command.
  2. Specify the package name, then choose Apply.

Modifying vendor information

The vendor element specifies the database type used for this DOML. You can choose from Standard, Instant DB, Oracle, Informix, MSQL, Sybase, and PostgreSQL.

To modify vendor information:

  1. Double click the vendor entry in the tree, then choose the vendor.
  2. Choose Apply.

Adding classes

  1. Select the package, then right-click and choose class from the Add menu or choose the Insert | class menu command.
  2. Specify any of the following attributes, then choose Apply.
Attribute Description
name The name of the class.
modifier Whether the data object is abstract, final, or neither. Abstract data objects can be extended by another data object. Final data objects cannot be extended nor be a subclass.
extends The name of a table of which this table is an extension.
use-oid Specifies whether or not to have an oid for every row.
lazy-loading Whether or not the data object uses lazy loading.
is-stored-proc Whether or not the data object is a stored procedure.
vendor The vendor name.
caching Specifies how the data object is cached: fully, partially, or not at all.
table The table name.

Adding fields

  1. Select the class, then right-click and choose field from the Add menu or choose the Insert | field menu command.
  2. Specify any of the following attributes, then choose Apply.
Attribute Description
name The name of the column.
constraint Whether or not the specified table row must exist.
sp-param-index Stored procedure parameter index.
foreignkeyfield Foreign key field.
foreignkeygroup Foreign key group.
can-query Whether or not the values of the column are used for queries.
primary-key Whether or not the column is a primary key.
index Whether or not the table column has an index.
sp-param-type Stored procedure parameter type.
constant Whether or not the column contains a constant value.
null-allowed Whether or not the column can contain null values.
database-type The internal SQL data type the database uses to store values.
java-type The Java data type returned by the data object to the user.
size The size of the data types that are commonly measured in width.

Adding Javadoc and default text

  1. Select the field, then right-click and choose Javadoc or default from the Add menu or choose the Insert | javadoc or Insert | default menu command.
  2. Specify text in the text box, then choose Apply.

Generating code

To generate Java source code:

  1. Choose the File | Generate Java Source command.
  2. Specify the directory in which to generate the Java source.
  3. Check the Overwrite checkbox if you want the entire contents of the directory overwritten with the new Java source code.
  4. Choose the Database Manager: EAS 4.x/JDBC or Enhydra 3.x.
  5. If you choose EAS 4.x/JDBC, you can optionally check one of the following settings:
    • Use Data Sources: If checked, uses JDBC 2, which uses data sources gotten by JNDI; if not checked uses JDBC 1, uses connections.
    • Generate EJB: If checked, generates EJB code.
  6. Click Generate.

For all the latest information on DODS, please refer to http://dods.enhydra.org
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