在本章中，我们将创建一个使用MySQL Reader和 Flatfile Writer(.txt)的Spring Batch应用程序.
Reader : 我们在应用程序中使用的Reader是 JdbcCursorItemReader 来从MySQL数据库中读取数据.
假设我们在MySQL数据库中创建了一个表，如下所示./p>
CREATE TABLE details.xml_mysql( person_id int(10) NOT NULL, sales VARCHAR(20), qty int(3), staffName VARCHAR(20), date VARCHAR(20) );
假设我们已将以下记录插入其中.
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)
作家 : 我们在应用程序中使用的Writer是 FlatFileItemWriter ，用于将数据写入 flatfile (.txt).
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，它只打印从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.除此之外，我们还为ItemReader，ItemProcessor和ItemWriter定义了bean. (这里，我们将它们与各个类相关联，并传递所需属性的值来配置它们.)
<beans xmlns = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/" xmlns:batch = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/" xmlns:xsi = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/XMLSchema-instance" xmlns:util = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/" xsi:schemaLocation = "http://www.springframework.org/schema/batch https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/spring-batch-2.2.xsd http://www.springframework.org/schema/beans https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/spring-beans-3.2.xsd"> <import resource = "../jobs/context.xml" /> <bean id = "tutorial" class = "Tutorial" scope = "prototype" /> <bean id = "itemProcessor" class = "CustomItemProcessor" /> <batch:job id = "helloWorldJob"> <batch:step id = "step1"> <batch:tasklet> <batch:chunk reader = "mysqlItemReader" writer = "flatFileItemWriter" processor = "itemProcessor" commit-interval = "10"> </batch:chunk> </batch:tasklet> </batch:step> </batch:job> <bean id = "mysqlItemReader" class = "org.springframework.batch.item.database.JdbcCursorItemReader" > <property name = "dataSource" ref = "dataSource" /> <property name = "sql" value = "select * from details.tutorialsdata" /> <property name = "rowMapper"> <bean class = "TutorialRowMapper" /> </property> </bean> <bean id = "flatFileItemWriter" class = " org.springframework.batch.item.file.FlatFileItemWriter"> <property name = "resource" value = "file:target/outputfiles/employee_output.txt"/> <property name = "lineAggregator"> <bean class = " org.springframework.batch.item.file.transform.PassThroughLineAggregator"/> </property> </bean> </beans>
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 = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/" xmlns:xsi = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/XMLSchema-instance" xmlns:jdbc = "https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/" xsi:schemaLocation = "http://www.springframework.org/schema/beans https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/spring-beans-3.2.xsd http://www.springframework.org/schema/jdbc https://img01.yuandaxia.cn/Content/img/tutorials/spring_batch/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 = "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> <bean id = "jobLauncher" class = "org.springframework.batch.core.launch.support.SimpleJobLauncher"> <property name = "jobRepository" ref = "jobRepository" /> </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>
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;
// Implementing the ItemProcessor interface
public class CustomItemProcessor implements ItemProcessor<Tutorial, Tutorial> {
@Override
public Tutorial process(Tutorial item) throws Exception {
System.out.println("Processing..." + item);
return item;
}
}以下是 TutorialRowMapper 将数据设置为 Tutorial 类的类.
public class TutorialRowMapper implements RowMapper<Tutorial> {
@Override
public Tutorial mapRow(ResultSet rs, int rowNum) throws SQLException {
Tutorial tutorial = new Tutorial();
tutorial.setTutorial_id(rs.getInt("tutorial_id"));
tutorial.setTutorial_title(rs.getString("tutorial_title"));
tutorial.setTutorial_author(rs.getString("tutorial_author"));
tutorial.setSubmission_date(rs.getString("submission_date"));
return tutorial;
}
}以下是教程上课.它是一个简单的Java类，带有 setter 和 getter 方法.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.
public class Tutorial {
private int tutorial_id;
private String tutorial_title;
private String tutorial_author;
private String submission_date;
public int getTutorial_id() {
return tutorial_id;
}
public void setTutorial_id(int tutorial_id) {
this.tutorial_id = tutorial_id;
}
public String getTutorial_title() {
return tutorial_title;
}
public void setTutorial_title(String tutorial_title) {
this.tutorial_title = tutorial_title;
}
public String getTutorial_author() {
return tutorial_author;
}
public void setTutorial_author(String tutorial_author) {
this.tutorial_author = tutorial_author;
}
public String getSubmission_date() {
return submission_date;
}
public void setSubmission_date(String submission_date) {
this.submission_date = submission_date;
}
@Override
public String toString() {
return " [id=" + tutorial_id + ", title=" +
tutorial_title + ",
author=" + tutorial_author + ", date=" +
submission_date + "]";
}
}以下是批量生产的代码处理.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"};
//创建应用程序上下文对象
ApplicationContext context = new ClassPathXmlApplicationContext(springConfig);
//创建作业启动器
JobLauncher jobLauncher =(JobLauncher)context.getBean("jobLauncher");
//创建作业
作业作业=(作业)context.getBean("helloWorldJob");
//执行JOB
JobExecution执行= jobLauncher.run(job，new JobParameters());
System.out.println("退出状态:"+ execution.getStatus());
}
}执行此应用程序时，它将产生以下输出.
May 09, 2017 5:44:48 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXml
ApplicationContext@3d646c37: startup date [Tue May
09 17:44:48 IST 2017]; root of context hierarchy
May 09, 2017 5:44:48 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
May 09, 2017 5:44:56 PM org.springframework.batch.core.launch.support.SimpleJobLauncher run
INFO: Job: [FlowJob: [name=helloWorldJob]] launched
with the following parameters: [{}]
May 09, 2017 5:44:56 PM org.springframework.batch.core.job.SimpleStepHandler handleStep
INFO: Executing step: [step1]
Processing...Report [id=101, title=Learn Java, author=Sanjay, date=06-05-2007]
Processing...Report [id=102, title=Learn MySQL, author=Abdul S, date=19-04-2007]
Processing...Report [id=103, title=Learn JavaFX, author=Krishna Kasyap, date=0607-2017]
May 09, 2017 5:44:57 PM org.springframework.batch.core.launch.support.SimpleJobLauncher run
INFO: Job: [FlowJob: [name=helloWorldJob]] completed with the following parameters:
[{}] and the following status: [COMPLETED]
Hello
Exit Status : COMPLETED这将生成带有以下内容的 .txt 文件.
Report [id=101, title=Learn Java, author=Sanjay, date=06-05-2007] Report [id=102, title=Learn MySQL, author=Abdul S, date=19-04-2007] Report [id=103, title=Learn JavaFX, author=Krishna Kasyap, date=06-07-2017]
