Reliable, scalable, easy-to-use, and cost-effective transparent persistence programming model for relational database access

We know you have been eager to see this new release. We think you will like the new features and functions designed to support Java^TM transparent persistence in your applications.

Java Transparent Persistence for Your Portal

Java Blend 2.0 software is Java "transparent persistence" for your Java programming language applications. Whether you are creating a 2-tier application, or an n-tier Application Server for your portal, the Java Blend software will scale to build and deploy applications which access tables with millions of rows, thousands of attributes, hundreds of simultaneous database connections, all without having to worry about SQL in your Java application code. And with the new mapping features in version 2.0, your enterprise Java applications can map most complex relationships while supporting multi-media objects like BLOBs.

Features Introduced in Java Blend 1.0

Automated Database to Java Object and Java Object to Database Mapping
Choose the mapping direction, then the Java Blend software automatically creates:

• For Database to Java Object Mapping
  the Java programming language source files that map to your relational tables and attributes
• For Java Object to Database Mapping
  The .SQL files for creating the database tables that map to your Java Objects

One-to-one, One-to-many, Many-to-many, and Inheritance Relationships
Foreign keys in the database are mapped to relationships in the Java classes.

Pessimistic and Optimistic concurrency control
Choose either database locking or rely on Java Blend's sophisticated modification detection and caching mechanism to isolate transactions and tune performance.

Multi-threaded transaction support
Java Blend can support simultaneous transactions within a single Java Virtual Machine.

Features New to Java Blend 2.0

Enterprise Scalability
Our Java Blend deployment server runtime can support applications ranging to millions of rows, thousands of attributes, and hundreds of simultaneous database connections.

Better Performance than Java Blend 1.0

• faster at mapping tables which makes programmers more productive when developing applications
• faster at retrieving and storing objects, which means better performance for deployed applications

Dynamic OQL
Now create and execute OQL (Object Query Language) statements on the fly, which gives you more flexibility in how you design your application.

Multiple Database Support
The Java Blend 2.0 runtime supports separate transactions over separate heterogeneous databases. Now you can partition your enterprise relational datastore and access the entire datastore from a single Java Blend runtime.

New Modeling Features
The object-to-relational mapping interface is packed with new mapping features designed to increase the numbers of tables and kinds of relationships that can be mapped.

• Mutable primary keys
  Model objects where the primary key may need to be changed during a transaction.
• Tables without primary keys
  Model objects where there is no primary key in the corresponding table.
• Support for non-nullable foreign keys
  Model objects where the foreign key cannot contain null values.
• One-way navigable relationships
  Java objects to DB only. Modeling Java objects with one way navigable relationships uses less memory than two-way navigable relationships, which means transactions using these objects execute more quickly.
• Support for DSet, DList relationships
  Expands the types of collections usable for relationships between persistent Java objects. Supports all methods in the corresponding Java 2 collection classes.
• Primary key containing foreign key
  Model relationships where the primary key overlaps with one or more foreign keys. For example, model relationships where the primary key is made up of two foreign keys.
• Join table with extra attributes
  Model relationships where a join table has additional attributes.
• BLOB Type support
  Persist multi-media Java objects using new BLOB type support.

Ease of Use Features

• Database exception handling
  The Java Blend software now captures more information about exceptions from the database and passes the information back to the application, which gives you more options for how to be responsive to database exceptions in your application.
• Save incomplete mappings
  If you want to leave your mapping and come back to it later, you can now save incomplete mappings. No SQL is unnecessarily generated until you have a complete mapping.
• Import multiple Java software packages
  Java objects to DB only. Now map multiple Java Object models by importing multiple Java packages. You can even define relationships and inheritance across more than one package.
• Connection configuration
  Now use a property file to define the number of database connections for the application to use.
• Support for Read Check
  Now you can specify on a per-object basis which objects have been read but not updated, but should be checked at commit. These objects will be validated against the database at the end of an optimistic transaction.

Localization

Sun will localize the Java Blend 2.0 displays, error messages, and codeset for Japanese. If you require localization of the tools to another language, please contact your Sun Account Representative to review your requirements.