import org.springframework.batch.item.ItemProcessor;
/**
 * 簡(jiǎn)單的ItemProcessor實(shí)現(xiàn)
 * 將客戶(hù)數(shù)據(jù)轉(zhuǎn)換為大寫(xiě)形式
 */
public class CustomerNameUpperCaseProcessor implements ItemProcessor<Customer, Customer> {
    @Override
    public Customer process(Customer customer) throws Exception {
        // 返回null表示跳過(guò)該數(shù)據(jù)項(xiàng)
        if (customer == null || customer.getName() == null) {
            return null;
        }
        // 創(chuàng)建新對(duì)象，避免修改原始數(shù)據(jù)
        Customer processedCustomer = new Customer();
        processedCustomer.setId(customer.getId());
        processedCustomer.setName(customer.getName().toUpperCase());
        processedCustomer.setEmail(customer.getEmail());
        return processedCustomer;
    }
}

import org.springframework.batch.item.validator.ValidatingItemProcessor;
import org.springframework.batch.item.validator.ValidationException;
import org.springframework.batch.item.validator.Validator;
import org.springframework.batch.item.support.CompositeItemProcessor;
/**
 * 配置驗(yàn)證處理器
 */
@Bean
public ValidatingItemProcessor<Customer> validatingProcessor() {
    ValidatingItemProcessor<Customer> processor = new ValidatingItemProcessor<>();
    // 配置自定義驗(yàn)證器
    processor.setValidator(new CustomerValidator());
    // 設(shè)置過(guò)濾模式（默認(rèn)拋出異常，這里設(shè)置為過(guò)濾無(wú)效項(xiàng)）
    processor.setFilter(true);
    return processor;
}
/**
 * 自定義驗(yàn)證器
 */
public class CustomerValidator implements Validator<Customer> {
    @Override
    public void validate(Customer customer) throws ValidationException {
        if (customer.getEmail() == null || !customer.getEmail().contains("@")) {
            throw new ValidationException("Invalid email format: " + customer.getEmail());
        }
    }
}

import org.springframework.batch.item.support.ClassifierCompositeItemProcessor;
import org.springframework.classify.Classifier;
/**
 * 配置分類(lèi)處理器
 */
@Bean
public ItemProcessor<Transaction, ProcessedTransaction> classifierProcessor() {
    ClassifierCompositeItemProcessor<Transaction, ProcessedTransaction> processor = 
            new ClassifierCompositeItemProcessor<>();
    // 配置分類(lèi)器
    processor.setClassifier(new TransactionTypeClassifier());
    return processor;
}
/**
 * 交易類(lèi)型分類(lèi)器
 */
public class TransactionTypeClassifier implements Classifier<Transaction, ItemProcessor<?, ? extends ProcessedTransaction>> {
    private final ItemProcessor<Transaction, ProcessedTransaction> creditProcessor;
    private final ItemProcessor<Transaction, ProcessedTransaction> debitProcessor;
    public TransactionTypeClassifier(
            ItemProcessor<Transaction, ProcessedTransaction> creditProcessor,
            ItemProcessor<Transaction, ProcessedTransaction> debitProcessor) {
        this.creditProcessor = creditProcessor;
        this.debitProcessor = debitProcessor;
    }
    @Override
    public ItemProcessor<Transaction, ProcessedTransaction> classify(Transaction transaction) {
        // 根據(jù)交易類(lèi)型選擇處理器
        if ("CREDIT".equals(transaction.getType())) {
            return creditProcessor;
        } else {
            return debitProcessor;
        }
    }
}

import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
/**
 * 配置帶異常處理的Step
 */
@Bean
public Step processingStep(
        StepBuilderFactory stepBuilderFactory,
        ItemReader<RawData> reader,
        ItemProcessor<RawData, ProcessedData> processor,
        ItemWriter<ProcessedData> writer,
        ProcessorExceptionHandler exceptionHandler) {
    return stepBuilderFactory.get("processingStep")
            .<RawData, ProcessedData>chunk(10)
            .reader(reader)
            .processor(processor)
            .writer(writer)
            .faultTolerant()
            // 配置跳過(guò)策略
            .skip(DataFormatException.class)
            .skipLimit(10)
            // 配置重試策略
            .retry(TransientDataAccessException.class)
            .retryLimit(3)
            // 配置異常監(jiān)聽(tīng)器
            .listener(exceptionHandler)
            .build();
}
/**
 * 處理器異常處理器
 */
public class ProcessorExceptionHandler implements ItemProcessListener<RawData, ProcessedData> {
    private static final Logger logger = LoggerFactory.getLogger(ProcessorExceptionHandler.class);
    @Override
    public void beforeProcess(RawData item) {
        // 處理前邏輯
    }
    @Override
    public void afterProcess(RawData item, ProcessedData result) {
        // 處理后邏輯
    }
    @Override
    public void onProcessError(RawData item, Exception e) {
        // 記錄處理錯(cuò)誤
        logger.error("Error processing item: {}", item, e);
        // 可以在這里進(jìn)行額外的錯(cuò)誤處理，如通知、記錄等
    }
}

import org.springframework.batch.item.ItemProcessor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
/**
 * 自定義客戶(hù)富化處理器
 */
@Component
public class CustomerEnrichmentProcessor implements ItemProcessor<Customer, Customer> {
    private final ExternalDataService externalDataService;
    @Autowired
    public CustomerEnrichmentProcessor(ExternalDataService externalDataService) {
        this.externalDataService = externalDataService;
    }
    @Override
    public Customer process(Customer customer) throws Exception {
        try {
            // 調(diào)用外部服務(wù)獲取附加數(shù)據(jù)
            CustomerRating rating = externalDataService.getCustomerRating(customer.getId());
            // 富化客戶(hù)數(shù)據(jù)
            customer.setRatingScore(rating.getScore());
            customer.setRiskLevel(calculateRiskLevel(rating.getScore()));
            customer.setLastUpdated(new Date());
            return customer;
        } catch (ServiceUnavailableException e) {
            // 處理暫時(shí)性錯(cuò)誤，可拋出Spring Batch可重試的異常
            throw new RetryableException("External service temporarily unavailable", e);
        } catch (Exception e) {
            // 記錄錯(cuò)誤并跳過(guò)該項(xiàng)
            logger.error("Error enriching customer: {}", customer.getId(), e);
            return null;
        }
    }
    private String calculateRiskLevel(int ratingScore) {
        if (ratingScore >= 80) return "LOW";
        if (ratingScore >= 60) return "MEDIUM";
        return "HIGH";
    }
}

import org.springframework.batch.core.partition.support.Partitioner;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.core.task.TaskExecutor;
/**
 * 配置并行處理Step
 */
@Bean
public Step parallelProcessingStep(
        StepBuilderFactory stepBuilderFactory,
        Partitioner dataPartitioner,
        TaskExecutor taskExecutor,
        Step workerStep) {
    return stepBuilderFactory.get("parallelProcessingStep")
            .partitioner("workerStep", dataPartitioner)
            .step(workerStep)
            .taskExecutor(taskExecutor)
            .gridSize(10) // 設(shè)置并行度
            .build();
}
/**
 * 具有緩存能力的處理器
 */
@Component
@StepScope
public class CachingItemProcessor implements ItemProcessor<InputData, OutputData> {
    private final ExternalService externalService;
    private final Map<String, ReferenceData> cache = new ConcurrentHashMap<>();
    @Autowired
    public CachingItemProcessor(ExternalService externalService) {
        this.externalService = externalService;
    }
    @Override
    public OutputData process(InputData data) throws Exception {
        // 使用緩存減少外部調(diào)用
        ReferenceData refData = cache.computeIfAbsent(
                data.getReferenceKey(),
                key -> externalService.getReferenceData(key)
        );
        // 使用引用數(shù)據(jù)處理輸入數(shù)據(jù)
        OutputData output = new OutputData();
        // 設(shè)置屬性...
        return output;
    }
}