Spring Batch - CSV 到 XML

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在本章中，我们将创建一个简单的 Spring Batch 应用程序，它使用 CSV 读取器和 XML 写入器。

Reader -我们在应用程序中使用的阅读器是FlatFileItemReader，用于从 CSV 文件读取数据。

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将数据写入 XML 文件。

处理器- 我们在应用程序中使用的处理器是一个自定义处理器，它仅打印从 CSV 文件读取的记录。

作业配置文件

以下是我们示例 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，我们还定义了 ItemReader、ItemProcessor 和 ItemWriter 的 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。）

<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> 

上下文.xml

以下是我们的 Spring Batch 应用程序的context.xml。在此文件中，我们将定义作业存储库、作业启动器和事务管理器等 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。

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; 
   } 
} 

教程FieldSetMapper.java

以下是TutorialFieldSetMapper 类，它将数据设置到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; 
   } 
}

教程.java类

以下是教程课程。它是一个简单的 Java 类，具有setter和getter方法。在此类中，我们使用注释将此类的方法与 XML 文件的标签关联起来。

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 + "]"; 
   } 
}  

应用程序.java

以下是启动批处理过程的代码。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()); 
   } 
}       

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。

<?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>