Spring Batch in Action

505 Pages·2011·7.9 MB·English

by  Arnaud Cogoluegnes

IN ACTION
Arnaud Cogoluègnes
Thierry Templier
Gary Gregory
Olivier Bazoud
M A N N I N G
Spring Batch in Action

Spring Batch in Action
ARNAUD COGOLUEGNES
THIERRY TEMPLIER
GARY GREGORY
OLIVIER BAZOUD
MANNING
SHELTER ISLAND
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1 2 3 4 5 6 7 8 9 10 – MAL – 16 15 14 13 12 11
brief contents
P 1 B ..................................................................1
ART ACKGROUND
1 ■ Introducing Spring Batch 3
2 ■ Spring Batch concepts 32
P 2 C S B ......................................................51
ART ORE PRING ATCH
3 ■ Batch configuration 53
4 ■ Running batch jobs 87
5 ■ Reading data 117
6 ■ Writing data 157
7 ■ Processing data 193
8 ■ Implementing bulletproof jobs 223
9 ■ Transaction management 251
P 3 A S B .............................................275
ART DVANCED PRING ATCH
10 ■ Controlling execution 277
11 ■ Enterprise integration 306
12 ■ Monitoring jobs 345
13 ■ Scaling and parallel processing 373
14 ■ Testing batch applications 407
v

contents
foreword xv
preface xvii
acknowledgments xviii
about this book xx
about the cover illustration xxvi
P 1 B ......................................................1
ART ACKGROUND
1 Introducing Spring Batch 3
1.1 What are batch applications? 4
1.2 Meet Spring Batch 5
Robustness and reliability 6 ■ Scaling strategies 7
1.3 Introducing the case study 8
The online store application 8 ■ Why build an online store with
batch jobs? 9 ■ Why use batch processes? 9 ■ The import product
use case 10
1.4 Reading and writing the product data 11
Anatomy of the read-write step 11 ■ Reading a flat file 14
Implementing a database item writer 17 ■ Configuring a database
item writer 18 ■ Configuring the read-write step 18
vii
viii CONTENTS
1.5 Decompressing the input file with a tasklet 20
Why compress the file? 20 ■ Implementing the decompression
tasklet 20 ■ Configuring the tasklet 22
1.6 Testing the batch process 23
Setting up the test infrastructure 23 ■ Leveraging SpEL for
configuration 25 ■ Writing the test for the job 26
1.7 Skipping incorrect lines instead of failing 28
1.8 Summary 31
2 Spring Batch concepts 32
2.1 The batch domain language 33
Why use a domain language? 33 ■ Main components of the
domain language 34 ■ How Spring Batch interacts with the
outside world 35
2.2 The Spring Batch infrastructure 36
Launching jobs and storing job metadata 36 ■ Configuring the
Spring Batch infrastructure in a database 37
2.3 Anatomy of a job 41
Modeling jobs with steps 42 ■ Running job instances and job
executions 46
2.4 Summary 50
P 2 C S B .........................................51
ART ORE PRING ATCH
3 Batch configuration 53
3.1 The Spring Batch XML vocabulary 54
Using the Spring Batch XML namespace 54 ■ Spring Batch XML
features 56
3.2 Configuring jobs and steps 57
Job entities hierarchy 57 ■ Configuring jobs 58 ■ Configuring
steps 60 ■ Configuring tasklets and chunks 61 ■ Configuring
transactions 69
3.3 Configuring the job repository 72
Choosing a job repository 72 ■ Specifying job repository parameters 73
3.4 Advanced configuration topics 75
Using step scope 75 ■ Leveraging SpEL 76 ■ Using listeners to
provide additional processing 78 ■ Configuration inheritance 83
3.5 Summary 86
CONTENTS ix
4 Running batch jobs 87
4.1 Launching concepts 88
Introducing the Spring Batch launcher API 88 ■ Synchronous vs.
asynchronous launches 89 ■ Overview of launching solutions 90
4.2 Launching from the command line 92
Using Spring Batch’s command-line job runner 92
4.3 Job schedulers 97
Using cron 98 ■ Using the Spring scheduler 99
4.4 Launching from a web application 103
Embedding Spring Batch in a web application 104 ■ Launching a
job with an HTTP request 105
4.5 Stopping jobs gracefully 109
Stopping a job for the operator 110 ■ Stopping a job for the
application developer 113
4.6 Summary 116
5 Reading data 117
5.1 Data reading concepts 118
5.2 Reading flat files 119
Configuring the FlatFileItemReader class 121 ■ Introducing the
DefaultLineMapper class 125 ■ Using the DefaultLineMapper
class 126 ■ Extracting character-separated fields 126
Creating objects from fields 128 ■ Reading JSON 130
Multiline records 132 ■ Reading heterogonous records 133
5.3 Reading XML files 135
5.4 Reading file sets 138
5.5 Reading from relational databases 139
Using JDBC item readers 139 ■ Using ORM item readers 148
5.6 Using other input sources 151
Services as input 151 ■ Reading from JMS 154
5.7 Implementing custom readers 155
5.8 Summary 156
6 Writing data 157
6.1 Data-writing concepts 158
6.2 Writing files 159
Writing flat files 159 ■ Writing XML files 173 ■ Writing file
sets 178