SpringItemProcessor.java

// referenced from http://docs.spring.io/spring-batch/trunk/reference/html/readersAndWriters.html
public class Foo {}

public class Bar {
    public Bar(Foo foo) {}
}

public class Foobar{
    public Foobar(Bar bar) {}
}

public class FooProcessor implements ItemProcessor<Foo,Bar>{
    public Bar process(Foo foo) throws Exception {
        //Perform simple transformation, convert a Foo to a Bar
        return new Bar(foo);
    }
}

public class BarProcessor implements ItemProcessor<Bar,FooBar>{
    public FooBar process(Bar bar) throws Exception {
        return new Foobar(bar);
    }
}

public class FoobarWriter implements ItemWriter<FooBar>{
    // write returns ?, which is returned from process.
    public void write(List<? extends FooBar> items) throws Exception {
        //write items
    }
}