The document describes the three phases of a batch component in Mule: input, process records, and on complete. The input phase prepares a collection object with the input message. The process records phase processes each record in the collection individually and in parallel. The on complete phase provides status information about the number of successful, failed, and total records. An example is also provided that uses a batch component to transform a CSV file to XML using data mapping and writes the output to a file.

2.  Batch component is used to process huge messages in batches. In
batch we have 3 phases.
1. Input
2. Process Records
3. On complete
Input:
Input phase is used to prepare a collection object with input
message. Because process records phase expects a collection object.

3. Process Records:
 Process Record phase expects a collection object to process the
each record of collection in individually and parallel. Here each object
of collection is a record.
On Complete:
 On complete phase is used to summarize the flow. Following
variables are available in On Complete phase to get the status of flow.
• Count of Successful records
• Count of Failure records
• Count of total records.

4. Example:
 In the following example, it explains how to transform CSV to XML using
batch. This example exposes a HTTP rest service.

5.  In the main flow input csv file path sets to payload and refer to a batch
job.

6.  In Input phase, an expression component is used to read file
(src/main/resources/input.csv) data. This expression component refers
to a file (src/main/resources/ReadFile.txt) which has code to read file
data. Another expression component has below expression to create a
collection object.
 payload = new com.techm.common.util.LineIterator(payload);
 LineIterator is our custom class which implements Iterator Interface to
implement collection object. Below is code of LineIterator class.

7. Note : Java Code Continuation from line 31 on next slide.

9.  In Process Records phase, we have two batch steps to transform
payload from csv to xml using datamapper and write the xml data into
a file. Second batch step contains batch commit. The message
processors which are in batch commit scope get execute depends of
size of batch commit.
 <batch:commit size="5" doc:name="Batch Commit">
 This batch commit get executed for every 5 records as configured.
 On Complete phase has one logger component which logs
successful, failure and total no of records.
 Note : SOAP UI project to test this application is placed in
src/test/resources.

10. Thank You All