PB 在 JAVA 代码中使用 JdbcBatchItemWriter 和 CompositeItemWriter - Spring-Batch

Question

我已经扩展了 Spring-Batch 官方网站 - Batch Processing Service 提供的批处理服务代码，并修改了 ItemWriter 以生成 CSV 并写入数据库。

我使用 CompositeItemWriter 写入 CSV 和数据库。 但是 JdbcBatchItemWriter 无法与 CompositeItemWriter 一起正常工作。代码如下所示。

    @Bean
public ItemWriter<Person> writer(DataSource dataSource) {
CompositeItemWriter<Person> cWriter = new CompositeItemWriter<Person>();   

// For DataBase 
JdbcBatchItemWriter<Person> writer = new JdbcBatchItemWriter<Person>();
    writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<Person>());
    writer.setSql("INSERT INTO people (first_name, last_name) VALUES (:firstName, :lastName)");
    writer.setDataSource(dataSource);

// For CSV
FlatFileItemWriter<Person> csvWriter = new FlatFileItemWriter<Person>();
csvWriter.setResource(new FileSystemResource(new File("./csv/new-data.csv")));
csvWriter.setShouldDeleteIfExists(true);
DelimitedLineAggregator<Person> lineAggregator = new DelimitedLineAggregator<Person>();
lineAggregator.setDelimiter(","); 

BeanWrapperFieldExtractor<Person> fieldExtractor = new BeanWrapperFieldExtractor<Person>();
String[] names = {"firstName", "lastName"};
fieldExtractor.setNames(names);
lineAggregator.setFieldExtractor(fieldExtractor);
csvWriter.setLineAggregator(lineAggregator);

List<ItemWriter<? super Person>> mWriter = new ArrayList<ItemWriter<? super Person>>();
mWriter.add(writer); // **Comment this line and the code works fine**
mWriter.add(csvWriter);
cWriter.setDelegates(mWriter);
    return cWriter;
}

评论这一行 - mWriter.add(writer);运行代码。这表明 CompositeItemWriter 可以很好地与 FlatFileitemWriter 一起工作，但不能与 JdbcBatchItemWriter 一起工作。我得到的错误是 -

or.springframework.jdbc.BadSqlGrammerException: PreparedStatementCallback; bad SQL grammar 
[insert into people(first_name, last_name) VALUES (:firstName, :lastName)]

Caused by: Syntax error in SQl statement "insert into people((first_name, last_name) VALUES (:[*]firstName, :lastName)"; expected"), DEFAULT, NOT, EXISTS, INTERSECTS, SELECT, FROM"; SQL Statement:

如何解析 JdbcBatchItemWriter 以与 CompositeItemWriter 一起正常工作？

Answer 1

这是 jdbc 自动配置的问题，在多个 itemWriter 的情况下没有运行。请以相同的顺序添加最后一行：-

JdbcBatchItemWriter<Person> writer = new JdbcBatchItemWriter<Person>();
writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<Person>());
writer.setSql("INSERT INTO people (first_name, last_name) VALUES (:firstName, :lastName)");
writer.setDataSource(dataSource);

writer.afterPropertiesSet();