在spring batch rocessor中执行查询

Question

在我的项目中，为了验证某个字段，我需要在spring批处理程序中执行一个查询。我怎么能这么做？谢谢！

---添加信息---这是步骤的定义

    @Bean
public Step step1(JdbcBatchItemWriter<CaricoDTO> step1Writer) {
    return stepBuilderFactory.get("step1").<CaricoDTO, CaricoDTO>chunk(10).reader(multiResourceItemReader())
            .processor(processorStep1()).writer(step1Writer).build();

}

    @Bean
public MultiResourceItemReader<CaricoDTO> multiResourceItemReader() {
    MultiResourceItemReader<CaricoDTO> resourceItemReader = new MultiResourceItemReader<CaricoDTO>();
    ArrayList<Integer> indexesToRemove = new ArrayList<Integer>();
    Resource[] inputResources = null;
    PathMatchingResourcePatternResolver patternResolver = new PathMatchingResourcePatternResolver();
    try {
        inputResources = patternResolver.getResources(inputPath);
    } catch (IOException e) {
        e.printStackTrace();
    }

    resourceItemReader.setResources(inputResources);
    resourceItemReader.setDelegate(step1Reader());
    resourceItemReader.setComparator(new FileComparator());
    return resourceItemReader;
}

    @Bean
public FlatFileItemReader<CaricoDTO> step1Reader() {
    FlatFileItemReader<CaricoDTO> reader = new FlatFileItemReader<CaricoDTO>();
    reader.setLinesToSkip(1);
    reader.setLineMapper(new DefaultLineMapper<CaricoDTO>() {
        {
            setLineTokenizer(new DelimitedLineTokenizer("|") {
                {
                    setNames(new String[] { ..... });
                }
            });
            setFieldSetMapper(new BeanWrapperFieldSetMapper<CaricoDTO>() {
                {
                    setTargetType(CaricoDTO.class);
                }
            });
        }
    });
    return reader;
}

    @Bean
public CaricoDTOItemProcessorStep1 processorStep1() {
    CaricoDTOItemProcessorStep1 processorStep1 = new CaricoDTOItemProcessorStep1();
    return processorStep1;
}

private String fileName;
private static final Logger log = LoggerFactory.getLogger(CaricoDTOItemProcessorStep1.class);

@Override
public CaricoDTO process(CaricoDTO carico) throws Exception {

    carico.setDataCaricamento(new Date(System.currentTimeMillis()));
    carico.setFileName(carico.getResource().getFilename());
    return carico;
}

public String getFileName() {
    return fileName;
}

public void setFileName(String fileName) {
    this.fileName = fileName;
}

}

这是我的作家

    @Bean
public JdbcBatchItemWriter<CaricoDTO> step1Writer(DataSource dataSource) {
    return new JdbcBatchItemWriterBuilder<CaricoDTO>()
            .itemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<>())
            .sql(....)
            .dataSource(dataSource).build();
}

Answer 1

考虑到主操作中的一些细节，我假设一般的解决方案会被接受。

给定一个经典的Spring批处理项目设置，您应该能够访问一个org.springframework.jdbc.core.jdbctemplatebean，该bean连接到目标javax.sql.datasource，您可以简单地将该bode>javax.sql.datasource插入到您的批处理协作器组件中：

• org.springframework.batch.item.itemReader
• org.springframework.batch.item.ItemWriter
• org.springframework.batch.item.itemprocessor

public class CaricoDTOItemProcessorStep1 implements ItemProcessor<CaricoDTO, CaricoDTO> {
    
    @Autowired
    private JdbcTemplate jdbcTemplate;

    private String fileName;
    
    private static final Logger log = LoggerFactory.getLogger(CaricoDTOItemProcessorStep1.class);
    
    @Override
    public CaricoDTO process(CaricoDTO item) throws Exception {
        boolean someValue = jdbcTemplate.queryForObject("SELECT some_field FROM some_table WHERE some_other_field = 0", (rs, rowNum) -> rs.getBoolean(0));
        if (someValue) {
            carico.setDataCaricamento(new Date(System.currentTimeMillis()));
            carico.setFileName(carico.getResource().getFilename());
            return carico;
        } else {
            return null; // causes the item to be discarded from processing
        }
    }
}

不用说，您的查询依赖于您的域用例，并且需要更新。