问弹簧批次统一多读取器结果

EN

public class User {
    Long id;
    String firstName;
    String lastName;
    String subscriptionCode;
}   

...
stepBuilderFactory.get("createUserStep1")
    .<User, User>chunk(1000)
    .reader(flatFileReader) // Read line from file and create partial user object (only get id, subscriptionCode)
    // Here - How to read DB using User.id read previously and extend User object with additionnal data
    .processor(new SkipDuplicatedUserItemProcessor()) // processor skip duplicated user
    .writer(itemWriter) // Write somewhere
    .build();