Spring Batch - XML 到 MySQL

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在本章中，我们将创建一个使用 XML Reader 和 MySQL Writer 的 Spring Batch 应用程序。

Reader - 我们在应用程序中使用的阅读器是StaxEventItemReader，用于从 XML 文档读取数据。

以下是我们在此应用程序中使用的输入 XML 文档。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。

<?xml version="1.0" encoding="UTF-8"?> 
<tutorials> 
   <tutorial>      
      <tutorial_id>1001</tutorial_id> 
      <tutorial_author>Sanjay</tutorial_author> 
      <tutorial_title>Learn Java</tutorial_title> 
      <submission_date>06-05-2007</submission_date> 
      <tutorial_icon>https://www.tutorialspoint.com/java/images/java-minilogo.jpg</tutorial_icon> 
      <tutorial_description>Java is a high-level programming language originally 
         developed by Sun Microsystems and released in 1995. 
         Java runs on a variety of platforms. 
         This tutorial gives a complete understanding of Java.');</tutorial_description> 
   </tutorial> 
    
   <tutorial>      
      <tutorial_id>1002</tutorial_id> 
      <tutorial_author>Abdul S</tutorial_author> 
      <tutorial_title>Learn MySQL</tutorial_title> 
      <submission_date>19-04-2007</submission_date> 
      <tutorial_icon>https://www.tutorialspoint.com/mysql/images/mysql-minilogo.jpg</tutorial_icon> 
      <tutorial_description>MySQL is the most popular 
         Open Source Relational SQL database management system. 
         MySQL is one of the best RDBMS being used for developing web-based software applications. 
         This tutorial will give you quick start with MySQL 
         and make you comfortable with MySQL programming.</tutorial_description> 
   </tutorial> 
    
   <tutorial>
      <tutorial_id>1003</tutorial_id> 
      <tutorial_author>Krishna Kasyap</tutorial_author> 
      <tutorial_title>Learn JavaFX</tutorial_title> 
      <submission_date>06-07-2017</submission_date> 
      <tutorial_icon>https://www.tutorialspoint.com/javafx/images/javafx-minilogo.jpg</tutorial_icon> 
      <tutorial_description>JavaFX is a Java library used to build Rich Internet Applications. 
         The applications developed using JavaFX can run on various devices 
         such as Desktop Computers, Mobile Phones, TVs, Tablets, etc. 
         This tutorial, discusses all the necessary elements of JavaFX that are required
         to develop effective Rich Internet Applications</tutorial_description> 
   </tutorial> 
</tutorials>

Writer -我们在应用程序中使用的writer是JdbcBatchItemWriter将数据写入 MySQL 数据库。假设我们在 MySQL 中创建了一个名为“details”的数据库表。

CREATE TABLE details.TUTORIALS( 
   tutorial_id int(10) NOT NULL, 
   tutorial_author VARCHAR(20), 
   tutorial_title VARCHAR(50), 
   submission_date VARCHAR(20), 
   tutorial_icon VARCHAR(200), 
   tutorial_description VARCHAR(1000) 
);

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，它将每条记录的数据写入 PDF 文档。

在批处理过程中，如果读取了“n”条记录或数据元素，那么对于每条记录，它将读取数据，处理它，并将数据写入Writer中。为了处理数据，它依赖于所传递的处理器。在本例中，在自定义处理器类中，我们编写了代码来加载特定的 PDF 文档、创建新页面、以表格格式将数据项写入 PDF。

最后，如果您执行此应用程序，它会从 XML 文档中读取所有数据项，将它们存储在 MySQL 数据库中，并将它们打印在给定 PDF 文档的各个页面中。

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" 
   xmlns:util = "http://www.springframework.org/schema/util" 
   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 
      http://www.springframework.org/schema/util     
      http://www.springframework.org/schema/util/spring-util-3.0.xsd ">  
  
   <import resource = "../jobs/context.xml" /> 
  
   <bean id = "itemProcessor" class = "CustomItemProcessor" /> 
   <batch:job id = "helloWorldJob"> 
      <batch:step id = "step1"> 
         <batch:tasklet>           
            <batch:chunk reader = "xmlItemReader" writer = "mysqlItemWriter" processor = "itemProcessor">
            </batch:chunk> 
         </batch:tasklet> 
      </batch:step> 
   </batch:job> 
                
   <bean id = "xmlItemReader" 
      class = "org.springframework.batch.item.xml.StaxEventItemReader"> 
      <property name = "fragmentRootElementName" value = "tutorial" /> 
      <property name = "resource" value = "classpath:resources/tutorial.xml" /> 
      <property name = "unmarshaller" ref = "customUnMarshaller" /> 
   </bean> 
      
   <bean id = "customUnMarshaller" class = "org.springframework.oxm.xstream.XStreamMarshaller">
      <property name = "aliases"> 
         <util:map id = "aliases"> 
            <entry key = "tutorial" value = "Tutorial" />            
         </util:map> 
      </property> 
   </bean>  
   <bean id = "mysqlItemWriter" class = "org.springframework.batch.item.database.JdbcBatchItemWriter"> 
      <property name = "dataSource" ref = "dataSource" /> 
      <property name = "sql"> 
         <value> 
            <![CDATA[insert into details.tutorials (tutorial_id, tutorial_author, tutorial_title, 
               submission_date, tutorial_icon, tutorial_description) 
               values (:tutorial_id, :tutorial_author, :tutorial_title, :submission_date, 
               :tutorial_icon, :tutorial_description);]]>
         </value> 
      </property>   
      
      <property name = "itemSqlParameterSourceProvider"> 
         <bean class = "org.springframework.batch.item.database.BeanPropertyItemSqlParameterSourceProvider" /> 
      </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.ResourcelessTransactionMana ger" />  
   <bean id = "jobLauncher" 
      class = "org.springframework.batch.core.launch.support.SimpleJobLauncher"> 
      <property name = "jobRepository" ref = "jobRepository" /> 
   </bean> 
  
   <!-- connect to MySQL database --> 
   <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，我们加载一个 PDF 文档，创建一个新页面，创建一个表，并为每个记录插入以下值：教程 ID、教程名称、作者、提交日期。

import java.io.File; 
import java.io.IOException;  

import org.apache.pdfbox.pdmodel.PDDocument; 
import org.apache.pdfbox.pdmodel.PDPage; 
import org.apache.pdfbox.pdmodel.PDPageContentStream; 
import org.apache.pdfbox.pdmodel.font.PDType1Font; 
import org.springframework.batch.item.ItemProcessor;  

public class CustomItemProcessor implements ItemProcessor<Tutorial, Tutorial> {  
   
   public static void drawTable(PDPage page, PDPageContentStream contentStream, 
      float y, float margin, String[][] content) throws IOException { 
      final int rows = content.length; 
      final int cols = content[0].length; 
      final float rowHeight = 50; 
      final float tableWidth = page.getMediaBox().getWidth()-(2*margin); 
      final float tableHeight = rowHeight * rows; 
      final float colWidth = tableWidth/(float)cols; 
      final float cellMargin=5f;  
      
      // draw the rows 
      float nexty = y ; 
      for (int i = 0; i <= rows; i++) {   
         contentStream.drawLine(margin,nexty,margin+tableWidth,nexty); 
         nexty-= rowHeight; 
      }  
      
      //draw the columns 
      float nextx = margin; 
      for (int i = 0; i <= cols; i++) {
         contentStream.drawLine(nextx,y,nextx,y-tableHeight); 
         nextx += colWidth; 
      }  
      
      // now add the text    
      contentStream.setFont(PDType1Font.HELVETICA_BOLD,12);  
      
      float textx = margin+cellMargin; 
      float texty = y-15; 
      for(int i = 0; i < content.length; i++){ 
         for(int j = 0 ; j < content[i].length; j++){ 
            String text = content[i][j]; 
            contentStream.beginText(); 
            contentStream.moveTextPositionByAmount(textx,texty); 
            contentStream.drawString(text); 
            contentStream.endText(); 
            textx += colWidth; 
         } 
        
         texty-=rowHeight; 
         textx = margin+cellMargin; 
      } 
   }  
   
   @Override 
   public Tutorial process(Tutorial item) throws Exception { 
      System.out.println("Processing..." + item); 
   
      // Creating PDF document object 
      PDDocument doc = PDDocument.load(new File("C:/Examples/test.pdf"));     
      
      // Creating a blank page 
      PDPage page = new PDPage(); 
      doc.addPage( page ); 
      PDPageContentStream contentStream =  new PDPageContentStream(doc, page);  
      
      String[][] content = {{"Id",""+item.getTutorial_id()},
      {"Title", item.getTutorial_title()}, 
      {"Authour", item.getTutorial_author()}, 
      {"Submission Date", item.getSubmission_date()}} ;  
      drawTable(page, contentStream, 700, 100, content);       
      
      contentStream.close(); 
      doc.save("C:/Examples/test.pdf" ); 
      System.out.println("Hello"); 
      return item; 
   }    
}      

教程FieldSetMapper.java

以下是 ReportFieldSetMapper 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 Tutorial class 
      Tutorial tutorial = new Tutorial(); 
   
      // Setting the fields from XML 
      tutorial.setTutorial_id(fieldSet.readInt(0));   
      tutorial.setTutorial_title(fieldSet.readString(1)); 
      tutorial.setTutorial_author(fieldSet.readString(2)); 
      tutorial.setTutorial_icon(fieldSet.readString(3)); 
      tutorial.setTutorial_description(fieldSet.readString(4));   
      return tutorial;  
   }  
} 

教程.java

以下是教程课程。它是一个带有setter和getter方法的简单类。

public class Tutorial { 
   private int tutorial_id; 
   private String tutorial_author; 
   private String tutorial_title; 
   private String submission_date; 
   private String tutorial_icon; 
   private String tutorial_description;   
   
   @Override 
   public String toString() { 
      return " [id=" + tutorial_id + ", author=" + tutorial_author  
         + ", title=" + tutorial_title + ", date=" + submission_date + ", icon =" 
         +tutorial_icon +", description = "+tutorial_description+"]"; 
   }  
   
   public int getTutorial_id() { 
      return tutorial_id; 
   }  
   
   public void setTutorial_id(int tutorial_id) { 
      this.tutorial_id = tutorial_id; 
   }  
   
   public String getTutorial_author() { 
      return tutorial_author; 
   }  
   
   public void setTutorial_author(String tutorial_author) { 
      this.tutorial_author = tutorial_author; 
   }  
   
   public String getTutorial_title() { 
      return tutorial_title; 
   } 
   
   public void setTutorial_title(String tutorial_title) { 
      this.tutorial_title = tutorial_title; 
   }  
   
   public String getSubmission_date() { 
      return submission_date; 
   }  
   
   public void setSubmission_date(String submission_date) { 
      this.submission_date = submission_date; 
   }  
   
   public String getTutorial_icon() { 
      return tutorial_icon; 
   }  
   
   public void setTutorial_icon(String tutorial_icon) { 
      this.tutorial_icon = tutorial_icon; 
   }  
   
   public String getTutorial_description() { 
      return tutorial_description; 
   }  
   
   public void setTutorial_description(String tutorial_description) { 
      this.tutorial_description = tutorial_description; 
   } 
}

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。

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 05, 2017 4:39:22 PM org.springframework.context.support.ClassPathXmlApplicationContext 
prepareRefresh 
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@306a30c7: 
startup date [Fri May 05 16:39:22 IST 2017]; root of context hierarchy 
May 05, 2017 4:39:23 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions 
May 05, 2017 4:39:32 PM org.springframework.batch.core.job.SimpleStepHandler handleStep 
INFO: Executing step: [step1] 
Processing... [id=1001, author=Sanjay, title=Learn Java, date=06-05-2007, 
icon =https://www.tutorialspoint.com/java/images/java-mini-logo.jpg, 
description = Java is a high-level programming language originally developed by Sun Microsystems 
and released in 1995. Java runs on a variety of platforms. 
This tutorial gives a complete understanding of Java.');] 
Hello 
Processing.. [id=1002, author=Abdul S, title=Learn MySQL, date=19-04-2007, 
icon =https://www.tutorialspoint.com/mysql/images/mysql-mini-logo.jpg, 
description = MySQL is the most popular Open Source Relational SQL database management system. 
MySQL is one of the best RDBMS being used for developing web-based software applications. 
This tutorial will give you quick start with MySQL and make you comfortable with MySQL programming.] 
Hello 
Processing... [id=1003, author=Krishna Kasyap, title=Learn JavaFX, date=06-072017, 
icon =https://www.tutorialspoint.com/javafx/images/javafx-mini-logo.jpg,
description = JavaFX is a Java library used to build Rich Internet Applications. 
The applications developed using JavaFX can run on various devices 
such as Desktop Computers, Mobile Phones, TVs, Tablets, etc. 
This tutorial, discusses all the necessary elements of JavaFX 
that are required to develop effective Rich Internet Applications] 
Hello 
May 05, 2017 4:39:36 PM 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 

如果您验证数据库中的details.tutorial表，它将显示以下输出 -

这将生成一个 PDF，其中每页都有记录，如下所示。