Oracle® Application Server TopLink Application Developer's Guide
10g Release 2 (10.1.2) Part No. B15901-01 |
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Enterprise applications rely on Java-to-database integration to implement objects and logic. OracleAS TopLink enables you to efficiently develop and refine enterprise applications. To fully understand OracleAS TopLink, you must understand the problems that enterprise application developers face and how OracleAS TopLink resolves them.
Java-to-database integration is a widely underestimated problem in enterprise Java applications. This complex problem involves more than reading from and writing to a database. The database world includes elements such as tables, rows, columns, and primary and foreign keys; the Java and J2EE world contains entity classes (regular Java classes or Enterprise JavaBeans (EJB) entity beans), business rules, complex relationships, and inheritance. Successful integration requires bridging these two fundamentally different technologies which is a challenging and resource-intensive problem.
The process of translating object-oriented data into relational data is referred to as object-relational (O-R) mapping. To enable an O-R solution, you must resolve the following O-R bridging issues:
Fundamentally different technologies
Different skill sets
Different staff and ownership for each of the technologies
Different modeling and design principles
Application developers need a product that enables them to integrate Java applications and relational databases, without compromising ideal application design or database integrity. In addition, Java developers need the ability to store (or persist) and retrieve business domain objects using a relational database as a repository.
The OracleAS TopLink solution is a persistence framework that manages O-R mapping in a seamless manner, and enables you to rapidly build applications that combine the best aspects of object technology and relational databases.
OracleAS TopLink provides a mature and powerful solution that addresses the disparity between Java objects and relational databases enabling you to:
Persist Java objects in virtually any relational database supported by a JDBC 2.0 compliant driver
Map any object model to any relational schema, using OracleAS TopLink Mapping Workbench graphical mapping tool
Use OracleAS TopLink successfully, even if you are unfamiliar with SQL or JDBC, because OracleAS TopLink offers a clean, object-oriented view of relational databases
In addition to providing industry leading O-R mapping capabilities, OracleAS TopLink provides flexibility, increases performance, and maximizes the productivity of your applications. OracleAS TopLink offers the following features:
Advanced object caching that improves performance by minimizing database access.
Rich query support that provides easy access to sophisticated, dynamic query languages and tools such as SQL, EJB QL, query by example, and Java expression-based queries.
A transactional framework that enables you to easily create and modify mapped objects. This framework integrates the complexities of a shared memory space and caches, and provides scalability that supports multiple server instances (clustering). Although the mechanisms involved are complex, OracleAS TopLink makes it easy to leverage this functionality by simplifying the task of writing transactional code that complies with database referential integrity and optimal access patterns.