如何从UI发送Spring批处理块大小

Question

Can someone help to understand how the chunk size 1 or 10 can be supplied from spring controller to step as a variable. Whether this will work with step scope here? or have to write in @beforeStep?

@Bean

public Step step1() {
    return stepBuilderFactory.get("step1")
            .<Person, Person> chunk(**10**)
            .reader(reader(null))
            .processor(processor())
            .writer(writer())
            .build();
}

Answer 1

The way you are trying to do it won't work. In order for a value to be passed in as a job parameter, the object it's being set on needs to be step scoped and a step itself can't be step scoped. What you could do is create a step scoped CompletionPolicy that uses that to determine if the chunk is complete. In short, configuring the Spring Batch CountingCompletionPolicy as a step scoped bean and configuring your step with that should allow you to set the max count via a job parameter.

You can read more about the CompletionPolicy and it's related implementations here: http://docs.spring.io/spring-batch/apidocs/org/springframework/batch/repeat/CompletionPolicy.html