Jakarta Struts Cookbook

10.3. Mapping SQL Data to Java Objects

Problem

You want to map SQL statements to Java objects without having to employ a full-blown object-relational mapping framework.

Solution

Use iBATIS SQL maps.

Discussion

There is a middle-ground in Java database access, a shadowy land that lies between straight JDBC and full-blown ORM, a place known as the iBATIS zone. iBATIS (pronounced "eye-bay-tis"), created by Clinton Begin, provides an elegant framework for mapping SQL statements and results to Java objects. It offers the simplicity and control of straight JDBC, yet it supports data mapping, caching, and transactions, features usually available from complex object-relational mapping tools. This recipe introduces you to the core feature of iBATIS: SQL maps. It doesn't delve into the full-functionality of iBATIS; you can find additional reference documentation and tutorials online at http://www.ibatis.com.

SQL maps allow you to specify how Java objects map to the inputs and outputs of an SQL statement. The inputs traditionally take the form of parameters bound to an SQL where clause. SQL maps let you map object properties to statement parameters. For output, SQL maps let you specify a Java object that maps to the result set returned by an SQL statement.

You can use iBATIS to access and display the data used in Recipe 10-2. Start by downloading iBATIS from http://www.ibatis.com. For this example, iBATIS Version 2.0.7 was used. Extract the distribution into a directory such as /ibatis-2.0.7. Copy ...