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CSV to XML

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2023-12-01

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。 本文档包含数据记录，其中指定了教程ID，教程作者，教程标题，提交日期，教程图标和教程描述等详细信息。

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。 除此之外，我们还为ItemReader，ItemProcessor和ItemWriter定义了bean。 （这里，我们将它们与各自的类相关联，并传递所需属性的值以进行配置。）

<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

以下是我们的Spring Batch应用程序的context.xml 。 在此文件中，我们将定义诸如作业存储库，作业启动程序和事务管理器之类的bean。

<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Processor类。 在这个类中，我们在应用程序中编写处理代码。 在这里，我们打印每条记录的内容。

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TutorialFieldSetMapper类，它将数据设置为Tutorial类。

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，我们使用注释将此类的方法与XML文件的标记相关联。

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。

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，它将生成以下输出。

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

这将生成包含以下内容的XML文件。

<?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>
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