6.8. Advanced writing techniques

You’ve seen how to use the item writers provided by Spring Batch and how to implement your own item writer. In this section, you learn more about Spring Batch item writers. To implement a complex job, it may be necessary to create something more complex than a custom item writer. You may need to chain writers to write to different targets. You may also need to choose between several writers, depending on the item.

6.8.1. Composing item writers

Spring Batch can configure only a single item writer for a chunk-oriented tasklet, and sometimes you need multiple writers for the same chunk. The classic Composite pattern provides this functionality. A composite wraps a set of objects and presents them as a single object. Figure 6.11 illustrates a CompositeItemWriter containing a set of item writers.