Spring Batch - CSV 到 XML
在本章中，我们将创建一个使用 CSV Reader 和 XML Writer 的简单 Spring Batch 应用程序。
Reader − 我们在应用程序中使用的 reader 是 FlatFileItemReader，用于从 CSV 文件中读取数据。
以下是我们在此应用程序中使用的输入 CSV 文件。 该文档包含指定详细信息的数据记录，例如教程 ID、教程作者、教程标题、提交日期、教程图标和教程描述。
1001, "Sanjay", "Learn Java", 06/05/2007 1002, "Abdul S", "Learn MySQL", 19/04/2007 1003, "Krishna Kasyap", "Learn JavaFX", 06/07/2017
Writer − 我们在应用程序中使用的 Writer 是 StaxEventItemWriter，用于将数据写入 XML 文件。
Processor − 我们在应用程序中使用的处理器是一个自定义处理器，它只打印从 CSV 文件中读取的记录。
jobConfig.xml
以下是我们的示例 Spring Batch 应用程序的配置文件。 在此文件中，我们将定义作业和步骤。 除了这些之外，我们还为 ItemReader、ItemProcessor 和 ItemWriter 定义了 bean。 （在这里，我们将它们与各自的类相关联，并传递所需属性的值来配置它们。）
实例
<beans xmlns = " http://www.springframework.org/schema/beans"
xmlns:batch = "http://www.springframework.org/schema/batch"
xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation = "http://www.springframework.org/schema/batch
http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
<import resource = "../jobs/context.xml" />
<bean id = "report" class = "Report" scope = "prototype" />
<bean id = "itemProcessor" class = "CustomItemProcessor" />
<batch:job id = "helloWorldJob">
<batch:step id = "step1">
<batch:tasklet>
<batch:chunk reader = "cvsFileItemReader" writer = "xmlItemWriter"
processor = "itemProcessor" commit-interval = "10">
</batch:chunk>
</batch:tasklet>
</batch:step>
</batch:job>
<bean id = "cvsFileItemReader"
class = "org.springframework.batch.item.file.FlatFileItemReader">
<property name = "resource" value = "classpath:resources/report.csv" />
<property name = "lineMapper">
<bean
class = "org.springframework.batch.item.file.mapping.DefaultLineMapper">
<property name = "lineTokenizer">
<bean
class = "org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
<property name = "names" value = "tutorial_id,
tutorial_author, Tutorial_title, submission_date" />
</bean>
</property>
<property name = "fieldSetMapper">
<bean class = "ReportFieldSetMapper" />
</property>
</bean>
</property>
</bean>
<bean id = "xmlItemWriter"
class = "org.springframework.batch.item.xml.StaxEventItemWriter">
<property name = "resource" value = "file:xml/outputs/tutorials.xml" />
<property name = "marshaller" ref = "reportMarshaller" />
<property name = "rootTagName" value = "tutorials" />
</bean>
<bean id = "reportMarshaller"
class = "org.springframework.oxm.jaxb.Jaxb2Marshaller">
<property name = "classesToBeBound">
<list>
<value>Tutorial</value>
</list>
</property>
</bean>
</beans>
Context.xml
以下是我们 Spring Batch 应用程序的 context.xml。 在这个文件中，我们将定义像作业存储库、作业启动器和事务管理器这样的 bean。
实例
<beans xmlns = "http://www.springframework.org/schema/beans"
xmlns:jdbc = "http://www.springframework.org/schema/jdbc"
xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation = "http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/jdbc
http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd">
<!-- stored job-meta in database -->
<bean id = "jobRepository"
class = "org.springframework.batch.core.repository.support.JobRepositoryFactoryBean">
<property name = "dataSource" ref = "dataSource" />
<property name = "transactionManager" ref = "transactionManager" />
<property name = "databaseType" value = "mysql" />
</bean>
<bean id = "transactionManager"
class = "org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
<bean id = "jobLauncher"
class = "org.springframework.batch.core.launch.support.SimpleJobLauncher">
<property name = "jobRepository" ref = "jobRepository" />
</bean>
<bean id = "dataSource" class = "org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name = "driverClassName" value = "com.mysql.jdbc.Driver" />
<property name = "url" value = "jdbc:mysql://localhost:3306/details" />
<property name = "username" value = "myuser" />
<property name = "password" value = "password" />
</bean>
<!-- create job-meta tables automatically -->
<jdbc:initialize-database data-source = "dataSource">
<jdbc:script location = "org/springframework/batch/core/schema-drop-mysql.sql" />
<jdbc:script location = "org/springframework/batch/core/schema-mysql.sql" />
</jdbc:initialize-database>
</beans>
CustomItemProcessor.java
以下是处理器类。 在这个类中，我们编写应用程序中的处理代码。 在这里，我们打印每条记录的内容。
实例
import org.springframework.batch.item.ItemProcessor;
public class CustomItemProcessor implements ItemProcessor<Tutorial, Tutorial> {
@Override
public Tutorial process(Tutorial item) throws Exception {
System.out.println("Processing..." + item);
return item;
}
}
TutorialFieldSetMapper.java
以下是将数据设置到 Tutorial 类的 TutorialFieldSetMapper 类。
实例
import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;
public class TutorialFieldSetMapper implements FieldSetMapper<Tutorial> {
@Override
public Tutorial mapFieldSet(FieldSet fieldSet) throws BindException {
//Instantiating the report object
Tutorial tutorial = new Tutorial();
//Setting the fields
tutorial.setTutorial_id(fieldSet.readInt(0));
tutorial.setTutorial_author(fieldSet.readString(1));
tutorial.setTutorial_title(fieldSet.readString(2));
tutorial.setSubmission_date(fieldSet.readString(3));
return tutorial;
}
}
Tutorial.java class
以下是 Tutorial 类。 它是一个带有 setter 和 getter 方法的简单 Java 类。 在这个类中，我们使用注解将这个类的方法与 XML 文件的标签相关联。
实例
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "tutorial")
public class Tutorial {
private int tutorial_id;
private String tutorial_author;
private String tutorial_title;
private String submission_date;
@XmlAttribute(name = "tutorial_id")
public int getTutorial_id() {
return tutorial_id;
}
public void setTutorial_id(int tutorial_id) {
this.tutorial_id = tutorial_id;
}
@XmlElement(name = "tutorial_author")
public String getTutorial_author() {
return tutorial_author;
}
public void setTutorial_author(String tutorial_author) {
this.tutorial_author = tutorial_author;
}
@XmlElement(name = "tutorial_title")
public String getTutorial_title() {
return tutorial_title;
}
public void setTutorial_title(String tutorial_title) {
this.tutorial_title = tutorial_title;
}
@XmlElement(name = "submission_date")
public String getSubmission_date() {
return submission_date;
}
public void setSubmission_date(String submission_date) {
this.submission_date = submission_date;
}
@Override
public String toString() {
return " [Tutorial id=" + tutorial_id + ",
Tutorial Author=" + tutorial_author + ",
Tutorial Title=" + tutorial_title + ",
Submission Date=" + submission_date + "]";
}
}
App.java
以下是启动批处理的代码。 在本课程中，我们将通过运行 JobLauncher 来启动批处理应用程序。
实例
import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
public static void main(String[] args) throws Exception {
String[] springConfig = { "jobs/job_hello_world.xml" };
// Creating the application context object
ApplicationContext context = new ClassPathXmlApplicationContext(springConfig);
// Creating the job launcher
JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");
// Creating the job
Job job = (Job) context.getBean("helloWorldJob");
// Executing the JOB
JobExecution execution = jobLauncher.run(job, new JobParameters());
System.out.println("Exit Status : " + execution.getStatus());
}
}
在执行此应用程序时，它将产生以下输出。
May 08, 2017 10:10:12 AM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing
org.springframework.context.support.ClassPathXmlApplicationContext@3d646c37: startup date
[Mon May 08 10:10:12 IST 2017]; root of context hierarchy
May 08, 2017 10:10:12 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
May 08, 2017 10:10:15 AM org.springframework.jdbc.datasource.init.ScriptUtils executeSqlScript
INFO: Executing step: [step1]
Processing... [Tutorial id=1001, Tutorial Author=Sanjay,
Tutorial Title=Learn Java, Submission Date=06/05/2007]
Processing... [Tutorial id=1002, Tutorial Author=Abdul S,
Tutorial Title=Learn MySQL, Submission Date=19/04/2007]
Processing... [Tutorial id=1003, Tutorial Author=Krishna Kasyap,
Tutorial Title=Learn JavaFX, Submission Date=06/07/2017]
May 08, 2017 10:10:21 AM org.springframework.batch.core.launch.support.SimpleJobLauncher run
INFO: Job: [FlowJob: [name=helloWorldJob]] completed with the following parameters:
[{}] and the following status: [COMPLETED]
Exit Status : COMPLETED
这将生成一个包含以下内容的 XML 文件。
实例
<?xml version = "1.0" encoding = "UTF-8"?>
<tutorials>
<tutorial tutorial_id = "1001">
<submission_date>06/05/2007</submission_date>
<tutorial_author>Sanjay</tutorial_author>
<tutorial_title>Learn Java</tutorial_title>
</tutorial>
<tutorial tutorial_id = "1002">
<submission_date>19/04/2007</submission_date>
<tutorial_author>Abdul S</tutorial_author>
<tutorial_title>Learn MySQL</tutorial_title>
</tutorial>
<tutorial tutorial_id = "1003">
<submission_date>06/07/2017</submission_date>
<tutorial_author>Krishna Kasyap</tutorial_author>
<tutorial_title>Learn JavaFX</tutorial_title>
</tutorial>
</tutorials>
