从平面文件(Flat File)中批量读取数据 章节用的是编码方式配置spring batch的job任务的，本节就是把上篇博客中job任务改成基于xml配置的方式配置job，因为公司中现在很大一部分还是用的xml方式配置job。
案例：还是读取User.txt文件中数据，并把每条数据中满足年纪是偶数的打印出来。
1、创建spring boot工程，并在pom.xml文件中引入所需要的jar包
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<!-- <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId>
<scope>runtime</scope> </dependency> -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.batch</groupId>
<artifactId>spring-batch-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>2、读文件
spring batch提供了FlatFileItemReader，用来读取文件，把每条数据映射到User对象中，通过下面方式映射
package com.lzj.batch;
import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;
public class UserFieldSetMapper implements FieldSetMapper<User> {
@Override
public User mapFieldSet(FieldSet fieldSet) throws BindException {
// TODO Auto-generated method stub
return new User(fieldSet.readString("ID"),
fieldSet.readString("NAME"),
fieldSet.readString("AGE"));
}
}3、处理
对每条数据进行处理，实现ItemProcessor即可
package com.lzj.batch;
import org.springframework.batch.item.ItemProcessor;
public class UserItemProcessor implements ItemProcessor<User, User> {
@Override
public User process(User item) throws Exception {
if (Integer.parseInt(item.getAge()) % 2 == 0) {
return item;
}
return null;
}
}4、写数据
实现ItemWriter即可
package com.lzj.batch;
import java.util.List;
import org.springframework.batch.item.ItemWriter;
public class UserWriter implements ItemWriter<User> {
@Override
public void write(List<? extends User> items) throws Exception {
for(User user : items){
System.out.println(user);
}
}
}5、配置Job作业
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:batch="http://www.springframework.org/schema/batch"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jdbc="http://www.springframework.org/schema/jdbc"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-4.3.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.3.xsd">
<bean id="reader" class="org.springframework.batch.item.file.FlatFileItemReader">
<property name="resource" value="data/User.txt"></property>
<property name="lineMapper" ref="lineMapper"></property>
<property name="linesToSkip" value="1"></property>
</bean>
<bean id="lineMapper" class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
<property name="lineTokenizer" ref="lineTokenizer"></property>
<property name="fieldSetMapper" ref="fieldSetMapper"></property>
</bean>
<bean id="lineTokenizer" class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
<property name="names" value="ID,NAME,AGE"></property>
</bean>
<bean id="fieldSetMapper" class="com.lzj.batch.UserFieldSetMapper"></bean>
<bean id="process" class="com.lzj.batch.UserItemProcessor"></bean>
<bean id="write" class="com.lzj.batch.UserWriter"></bean>
<!-- 选用内存级别的数据库，不在需要用oracle、mysql等数据库,采用h2数据库，不需要手动配置，只需要的pom.xml文件中引入h2即可 -->
<bean id="jobRepository" class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
<property name="transactionManager" ref="transactionManager"></property>
</bean>
<bean id="executor" class="org.springframework.core.task.SimpleAsyncTaskExecutor"></bean>
<bean id="laucher" class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
<property name="jobRepository" ref="jobRepository"></property>
<property name="taskExecutor" ref="executor"></property>
</bean>
<bean id="transactionManager" class="org.springframework.batch.support.transaction.ResourcelessTransactionManager"/>
<batch:job id="jobExample">
<batch:step id="stepExample">
<batch:tasklet>
<batch:chunk reader="reader" processor="process" writer="write"
commit-interval="3">
</batch:chunk>
</batch:tasklet>
</batch:step>
</batch:job>
</beans>6、run，启动job
public class DemoApplication {
public static void main(String[] args) throws JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException, JobParametersInvalidException {
ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("job.xml");
SimpleJobLauncher launcher = (SimpleJobLauncher) ctx.getBean("laucher");
Job job = (Job) ctx.getBean("jobExample");
System.out.println(launcher);
System.out.println(job);
launcher.run(job, new JobParameters());
ctx.close();
}
}工程目录
