📜  Spring Batch-从XML到MySQL

📅  最后修改于: 2020-11-11 06:52:02             🧑  作者: Mango


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。

阅读器-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。本文档包含数据记录,这些数据记录指定了详细信息,例如教程ID,教程作者,教程标题,提交日期,教程图标和教程说明。

 
 
         
      1001 
      Sanjay 
      Learn Java 
      06-05-2007 
      https://www.tutorialspoint.com/java/images/java-minilogo.jpg 
      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.'); 
    
    
         
      1002 
      Abdul S 
      Learn MySQL 
      19-04-2007 
      https://www.tutorialspoint.com/mysql/images/mysql-minilogo.jpg 
      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. 
    
    
   
      1003 
      Krishna Kasyap 
      Learn JavaFX 
      06-07-2017 
      https://www.tutorialspoint.com/javafx/images/javafx-minilogo.jpg 
      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 
    

作家-我们正在使用的应用程序的作者JdbcBatchItemWriter将数据写入到MySQL数据库。假设我们已经在MySQL中的一个名为“ details”的数据库中创建了一个表。

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自定义处理器,它将每个记录的数据写入PDF文档。

在批处理中,如果读取了“ n”个记录或数据元素,则对于每个记录,它将读取数据,对其进行处理并将数据写入Writer。为了处理数据,它在传递的处理器上进行中继。在这种情况下,在定制处理器类中,我们编写了代码以加载特定的PDF文档,创建新页面,并将数据项以表格格式写入PDF。

最后,如果执行此应用程序,它将从XML文档中读取所有数据项,将它们存储在MySQL数据库中,并在给定的PDF文档中将它们打印在单独的页面中。

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,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以对其进行配置。)

  
  
    
  
    
    
       
                    
            
             
          
       
    
                
    
       
       
       
    
      
   
       
          
                        
          
       
     
    
       
       
          
            
          
         
      
       
          
       
    
     

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,作业启动器和事务管理器之类的Bean。

 
   
   
    
       
       
       
     
 
     
    
       
    
  
    
    
       
       
       
       
     
 
    
      
         
       
    
   

CustomItemProcessor.java

以下是处理器类。在此类中,我们在应用程序中编写处理代码。在这里,我们正在加载PDF文档,创建新页面,创建表并为每个记录插入以下值:教程ID,教程名称,作者,提交日期在表中。

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 {  
   
   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; 
   }    
}      

TutorialFieldSetMapper.java

以下是ReportFieldSetMapper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 { 
   
   @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;  
   }  
} 

Tutorial.java

以下是Tutorial类。这是带有settergetter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; 
   } 
}

App.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()); 
   }    
} 

在执行此应用程序时,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-

tutorial _id tutorial _author tutorial _title submission _date tutorial _icon tutorial _description
1001 Sanjay Learn Java 06-05-2007 https://www.tutorials
point.com
/java/images/
java-mini-logo.jpg
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.
1002 Abdul S Learn MySQL 19-04-2007 https://www. tutorialspoint.com
/mysql/images /mysql-minilogo.jpg
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.
1003 Learn JavaFX Krishna Kasyap 06-07-2017 https://www. tutorialspoint.com
/javafx/images/ javafx-minilogo.jpg
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.

这将生成一个PDF,其中包含每个页面上的记录,如下所示。

页面缩略图