Spring-Batch将CSV文件转为XML文件

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_amount
devendra, 1234, 31/10/2015, 10000
john, 2134, 3/12/2015, 12321
robin, 2134, 2/02/2015, 23411

转换成的xml文件如下：record.xml

<?xml version="1.0" encoding="UTF-8"?><transactionRecord>
<transactionRecord>
    <amount>10000.0</amount>
    <transactionDate>2015-10-31T00:00:00+08:00</transactionDate>
    <userId>1234</userId>
    <username>devendra</username>
</transactionRecord>
<transactionRecord>
    <amount>12321.0</amount>
    <transactionDate>2015-12-03T00:00:00+08:00</transactionDate>
    <userId>2134</userId>
    <username>john</username>
</transactionRecord>
<transactionRecord>
    <amount>23411.0</amount>
    <transactionDate>2015-02-02T00:00:00+08:00</transactionDate>
    <userId>2134</userId>
    <username>robin</username>
</transactionRecord>

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
@Bean
public 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

@Bean
public ItemReader<Transaction> itemReader() throws UnexpectedInputException, ParseException {
    // 数据来源
    Resource inputCsv = new ClassPathResource("demo01/input/record.csv");

    // Spring Batch的内置reader
    FlatFileItemReader<Transaction> reader = new FlatFileItemReader<>();
    DelimitedLineTokenizer tokenizer = new DelimitedLineTokenizer();
    String[] tokens = {"username", "userid", "transactiondate", "amount"};
    tokenizer.setNames(tokens);
    reader.setResource(inputCsv);
    DefaultLineMapper<Transaction> lineMapper = new DefaultLineMapper<Transaction>();
    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

@Bean
public ItemWriter<Transaction> itemWriter(Marshaller marshaller) throws MalformedURLException {
    String userHome = System.getProperty("user.home");
    Resource outputXml = new FileSystemResource(userHome + "/output/demo01/record.xml");

    StaxEventItemWriter<Transaction> itemWriter = new StaxEventItemWriter<Transaction>();
    itemWriter.setMarshaller(marshaller);
    itemWriter.setRootTagName("transactionRecord");
    itemWriter.setResource(outputXml);
    return itemWriter;
}

2.5 定义Processor

@Bean
public ItemProcessor<Transaction, Transaction> itemProcessor() {
    return new CustomItemProcessor();
}

2.6 定义Job和Step

@Bean
protected Step step1(ItemReader<Transaction> reader, ItemProcessor<Transaction, Transaction> processor, ItemWriter<Transaction> writer) {
    return steps.get("step1")
        .<Transaction, Transaction>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 spring-batch