📅 最后修改于: 2020-11-11 06:54:09 🧑 作者: Mango
在本章中，我们将创建一个使用MySQL阅读器和XML 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JdbcCursorItemReader ，用于从MySQL数据库读取数据。
假设我们已经在MySQL数据库中创建了一个表，如下所示-
CREATE TABLE details.xml_mysql(
person_id int(10) NOT NULL,
sales VARCHAR(20),
qty int(3),
staffName VARCHAR(20),
date VARCHAR(20)
);
假设我们在其中插入了以下记录。
mysql> select * from tutorialsdata;
+-------------+-----------------+----------------+-----------------+
| tutorial_id | tutorial_author | tutorial_title | submission_date |
+-------------+-----------------+----------------+-----------------+
| 101 | Sanjay | Learn Java | 06-05-2007 |
| 102 | Abdul S | Learn MySQL | 19-04-2007 |
| 103 | Krishna Kasyap | Learn JavaFX | 06-07-2017 |
+-------------+-----------------+----------------+-----------------+
3 rows in set (0.00 sec)
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。
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。
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。)
Tutorial
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。
以下是Processor类。在此类中，我们在应用程序中编写处理代码。在这里，我们正在打印每个记录的内容。
import org.springframework.batch.item.ItemProcessor;
public class CustomItemProcessor implements ItemProcessor {
@Override
public Tutorial process(Tutorial item) throws Exception {
System.out.println("Processing..." + item);
return item;
}
}
以下是TutorialRowMapper类，它将数据设置为Tutorial类。
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
public class TutorialRowMapper implements RowMapper {
@Override
public Tutorial mapRow(ResultSet rs, int rowNum) throws SQLException {
Tutorial tutorial = new Tutorial();
tutorial.setTutorial_id(rs.getInt("tutorial_id"));
tutorial.setTutorial_author(rs.getString("tutorial_author"));
tutorial.setTutorial_title(rs.getString("tutorial_title"));
tutorial.setSubmission_date(rs.getString("submission_date"));
return tutorial;
}
}
以下是Tutorial类。这是带有setter和getter方法的简单Java类。在此类中，我们使用批注将此类的方法与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 = "details")
public class Tutorial {
int tutorial_id;
String tutorial_author;
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;
}
public String toString() {
return " [Tutorial Id=" + tutorial_id + ",
Tutorial Author =" + tutorial_author + ",
Tutorial Title =" + tutorial_title + ",
Submission Date =" + submission_date + "]";
}
}
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。
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 11:32:06 AM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@3d646c37:
startup date [Mon May 08 11:32:06 IST 2017]; root of context hierarchy
May 08, 2017 11:32:06 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [jobs/job_hello_world.xml]
May 08, 2017 11:32:07 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
May 08, 2017 11:32:14 AM org.springframework.batch.core.job.SimpleStepHandler handleStep
INFO: Executing step: [step1]
Processing... [Tutorial Id=101, Tutorial Author=Sanjay,
Tutorial Title=Learn Java, Submission Date=06-05-2007]
Processing... [Tutorial Id=102, Tutorial Author=Abdul S,
Tutorial Title=Learn MySQL, Submission Date=19-04-2007]
Processing... [Tutorial Id=103, Tutorial Author=Krishna Kasyap,
Tutorial Title=Learn JavaFX, Submission Date=06-07-2017]
May 08, 2017 11:32:14 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
这将生成具有以下内容的XML文件。
06-05-2007
Sanjay
Learn Java
19-04-2007
Abdul S
Learn MySQL
06-07-2017
Krishna Kasyap
Learn JavaFX