1 介绍

用Spring Batch实现一个简单的需求，将csv文件转换成xml文件。

csv文件如下：record.csv

username, user_id, transaction_date, transaction_amountdevendra, 1234, 31/10/2015, 10000john, 2134, 3/12/2015, 12321robin, 2134, 2/02/2015, 23411

转换成的xml文件如下：record.xml

    
    
         
      
       10000.0
          
      
       2015-10-31T00:00:00+08:00
          
      
       1234
          
      
       devendra
      
     
         
      
       12321.0
          
      
       2015-12-03T00:00:00+08:00
          
      
       2134
          
      
       john
      
     
         
      
       23411.0
          
      
       2015-02-02T00:00:00+08:00
          
      
       2134
          
      
       robin
      
     
    

2 实现

下面用Spring Batch实现，思路很简单，定义一个Reader读record.csv，定义一个Writer写record.xml

2.1 用Java来配置

SpringConfig.java，部分代码

// 数据源@Beanpublic DataSource dataSource() {    DriverManagerDataSource dataSource = new DriverManagerDataSource();    dataSource.setDriverClassName("org.sqlite.JDBC");    dataSource.setUrl("jdbc:sqlite:repository.sqlite");    return dataSource;}// 事务管理器private PlatformTransactionManager getTransactionManager() {    return new ResourcelessTransactionManager();}// 任务仓库private JobRepository getJobRepository() throws Exception {    JobRepositoryFactoryBean factory = new JobRepositoryFactoryBean();    factory.setDataSource(dataSource());    factory.setTransactionManager(getTransactionManager());    // JobRepositoryFactoryBean's methods Throws Generic Exception,    // it would have been better to have a specific one    factory.afterPropertiesSet();    return (JobRepository) factory.getObject();}// 任务加载器public JobLauncher getJobLauncher() throws Exception {    SimpleJobLauncher jobLauncher = new SimpleJobLauncher();    // SimpleJobLauncher's methods Throws Generic Exception,    // it would have been better to have a specific one    jobLauncher.setJobRepository(getJobRepository());    jobLauncher.afterPropertiesSet();    return jobLauncher;}

2.2 创建DTO对象

创建一个Transaction.java用来传输record.csv中的每行数据

package com.yysue.batch.demo01.model;import java.util.Date;import javax.xml.bind.annotation.XmlRootElement;@SuppressWarnings("restriction")@XmlRootElement(name = "transactionRecord")public class Transaction {    private String username;    private int userId;    private Date transactionDate;    private double amount;    // get/set...}

2.3 定义ItemReader

@Beanpublic ItemReader
    
      itemReader() throws UnexpectedInputException, ParseException {    // 数据来源    Resource inputCsv = new ClassPathResource("demo01/input/record.csv");    // Spring Batch的内置reader    FlatFileItemReader
     
       reader = new FlatFileItemReader<>();    DelimitedLineTokenizer tokenizer = new DelimitedLineTokenizer();    String[] tokens = {"username", "userid", "transactiondate", "amount"};    tokenizer.setNames(tokens);    reader.setResource(inputCsv);    DefaultLineMapper
      
        lineMapper = new DefaultLineMapper
       
        ();    lineMapper.setLineTokenizer(tokenizer);    lineMapper.setFieldSetMapper(new RecordFieldSetMapper());    reader.setLinesToSkip(1); // 文件开头需要忽略的行数    reader.setLineMapper(lineMapper);    return reader;}
       
      
     
    

2.4 定义ItemWriter

@Beanpublic ItemWriter
    
      itemWriter(Marshaller marshaller) throws MalformedURLException {    String userHome = System.getProperty("user.home");    Resource outputXml = new FileSystemResource(userHome + "/output/demo01/record.xml");    StaxEventItemWriter
     
       itemWriter = new StaxEventItemWriter
      
       ();    itemWriter.setMarshaller(marshaller);    itemWriter.setRootTagName("transactionRecord");    itemWriter.setResource(outputXml);    return itemWriter;}
      
     
    

2.5 定义Processor

@Beanpublic ItemProcessor
    
      itemProcessor() {    return new CustomItemProcessor();}
    

2.6 定义Job和Step

@Beanprotected Step step1(ItemReader
    
      reader, ItemProcessor
     
       processor, ItemWriter
      
        writer) {    return steps.get("step1")        .
       
        chunk(10)        .reader(reader)        .processor(processor)        .writer(writer)        .build();}@Bean(name = "firstBatchJob")public Job job(@Qualifier("step1") Step step1) {    return jobs.get("firstBatchJob").start(step1).build();}
       
      
     
    

2.7 定义主程序

App.java

public static void main(final String[] args) {    // Spring Java config    final AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();    context.register(SpringConfig.class);    context.register(SpringBatchConfig.class);    context.refresh();    // Spring xml config    // ApplicationContext context = new ClassPathXmlApplicationContext("demo01/spring-batch.xml");    final JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");    final Job job = (Job) context.getBean("firstBatchJob");    System.out.println("Starting the batch job");    try {        final JobExecution execution = jobLauncher.run(job, new JobParameters());        System.out.println("Job Status : " + execution.getStatus());        System.out.println("Job succeeded");    } catch (final Exception e) {        e.printStackTrace();        System.out.println("Job failed");    }    System.exit(0);}

运行主程序，会读取项目的resources/demo01/input/record.csv文件，在用户目录下生成文件 xml文件为：output/demo01/record.xml

3 总结

本例完整实现