New JobParameter Types Required [BATCH-1581]

[spring-projects-issues]

Tomasz Blachowicz opened BATCH-1581 and commented

Currently there is support only for the limited number of types of JobParameter. It is required that other primitive types such as Integer or Boolean are supported as well.

This would particularly useful when dealing with readers such as HibernateCursorItemReader. The reader can gives ability to provide the parameters to be bound to the query (prepared statement parameters). However there is no straightforward way to provide the Integer of Boolean values for parameters that causes the reader to fail with ClassCastException. This is because the Spring injection mechanism doesn't have a chance to convert the values as it would do for regular properties.

It would be also useful to have implementation of enum JobParameters.

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No further details from BATCH-1581

[spring-projects-issues]

Dave Syer commented

You can use Spring EL to make objects of an explicit type, e.g. "#{new Integer('1')}", or "#{T(my.company.MyEnum).valueOf('FOO')}". In the light of that I am reluctant to add more complications to the JobParameters (mainly because of the persistence requirements).

[spring-projects-issues]

Tomasz Blachowicz commented

EL is great, but I'm not sure if it can be used with Spring 2.5 setup, that I deal with currently. BTW, how would Spring EL work with JobParameter? Is this something like "#{new Integer(#{jobParameters[intAsString]})}"?

I've implemented some changes to Spring Batch Core to provide support for Integer and Boolean types. IT seems that it works OK. For the persistence I use existing columns. In case the parameter is of type Integer the value is stored in LONG_VAL column and the Boolean value is stored in STRING_VALUE. What is your opinion on such approach?

[spring-projects-issues]

Dave Syer commented

Thanks for trying it out. I just don't think we should put any effort into supporting Spring 2.5 when those features are obsolete with the current version of the framework (3.0). With Spring 2.5 it should still work if you initialise your map values with inner bean definitions, e.g.

<entry key="foo"><bean class="java.lang.Integer"><constructor-arg value="#{jobParameters['foo']}"/></bean></entry>

It's not pretty, but it works and it's really a corner case.

[spring-projects-issues]

Dave Syer commented

Or even (slightly prettier):

<entry key="foo"><value type="java.lang.Integer">#{jobParameters['foo']}</value></entry> 

[spring-projects-issues]

Tomasz Blachowicz commented

Dave, thanks for the explanation. I have already used that approach with java.lang.Integer.valueOf as factory method.