Question

如何根据商品属性更改或选择特定的作者？例如，我需要写入不同的SQL表（表A和B）。

if（item.myBoolean == true）{写入A和B}否则{仅写在A上}

如何选择使用JdbcBatchItemWriter？（实际上我使用CompositeItemWriter写入我的JdbcBatchItemWriter）我是否需要创建自定义ItemWriter“decider”或者还有另一种最佳解决方案（来自处理器）？

Answer 1

我使用ClassifierCompositeItemWriter

找到了解决方案

ClassifierCompositeItemWriter<Subscription> classifierCompositeItemWriter = new ClassifierCompositeItemWriter<Subscription>();      
classifierCompositeItemWriter.setClassifier(new Classifier<Subscription, ItemWriter<? super Subscription>>() {          
    @Override
    public ItemWriter<? super Subscription> classify(Subscription classifiable) {
        ItemWriter<? super Subscription> itemWriter = null;
        if(classifiable.isComplex()) { // condition
            itemWriter = compositeItemWriter; // I use compositeItemWriter to write on A and B
        } else {
            itemWriter = subscriptionJdbcWriter; // I use single JdbcBatchItemWriter to write only on A
        }
        log.info("Subscription would be classified with " + itemWriter.getClass().getSimpleName());
        return itemWriter;
    }
});

Answer 2

 @Bean
    public ItemWriter<Person> itemWriter(DataSource dataSource) {
        BackToBackPatternClassifier classifier = new BackToBackPatternClassifier();
        classifier.setRouterDelegate(new AggGroupClassifier());
        classifier.setMatcherMap(new HashMap<String, ItemWriter<? extends Person>>() {
            {
                put("A", writerA(dataSource));
                put("B", writerB(dataSource));
                put("C", writerC(dataSource));

            }
        });
        ClassifierCompositeItemWriter<Person> writer = new ClassifierCompositeItemWriter<Person>();
        writer.setClassifier(classifier);
        return writer;      
        }


public class AggGroupClassifier {

    @Classifier
    public String classify(Person person) {
        return person.getAgeGroup();

    }
}

Spring Batch writer取决于已处理的项目

2 个答案: