springbatch学习笔记2：使用批处理操作数据库

在上一篇对springbatch简单有了了解，接下来加入操作数据库操作

需要用到两张表：

需求：将这两个表的信息按照班级关联并输出为txt文件

1.创建项目引入依赖：

<dependency>
            <groupId>org.springframework.batch</groupId>
            <artifactId>spring-batch-core</artifactId>
            <version>LATEST</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.2.2.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.45</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.11</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.8</version>
        </dependency>
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper</artifactId>
            <version>3.4.6</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.3</version>
        </dependency>

2.编辑实体类，mapper等：

package com.zs.springbatch.model;

import lombok.Data;
import lombok.experimental.Accessors;

import javax.persistence.*;
import java.io.Serializable;

/**
 * create by Mybatis-generator
 */
@Table(name = "batch_class")
@Data
@Accessors(chain = true)
public class BatchClass implements Serializable {
    @Id
    @Column(name = "c_id")
    @GeneratedValue(generator = "JDBC")
    private Long cId;

    @Column(name = "c_name")
    private String cName;

    @Column(name = "c_teacher")
    private String cTeacher;

    private static final long serialVersionUID = 1L;

}

package com.zs.springbatch.model;

import lombok.Data;
import lombok.experimental.Accessors;

import javax.persistence.*;
import java.io.Serializable;

/**
 * create by Mybatis-generator
 */
@Table(name = "batch_student")
@Data
@Accessors(chain = true)
public class BatchStudent implements Serializable {
    @Id
    @Column(name = "s_id")
    @GeneratedValue(generator = "JDBC")
    private Long sId;

    @Column(name = "s_name")
    private String sName;

    @Column(name = "s_age")
    private String sAge;

    @Column(name = "s_class")
    private String sClass;

    private static final long serialVersionUID = 1L;
}

package com.zs.springbatch.mapper;

import com.zs.springbatch.model.BatchClass;
import tk.mybatis.mapper.common.Mapper;

/**
 * Created by Mybatis Generator
 */
public interface BatchClassMapper extends Mapper<BatchClass> {
}

package com.zs.springbatch.mapper;

import com.zs.springbatch.model.BatchStudent;
import tk.mybatis.mapper.common.Mapper;

/**
 * Created by Mybatis Generator
 */
public interface BatchStudentMapper extends Mapper<BatchStudent> {
}

mapper.xml就不写了，以上内容都是自动生成代码，详细可以看：https://github.com/Zs-xiazhi/springboot

手动编辑转存文件中的实体类型：

package com.zs.springbatch.model;

import lombok.Data;
import lombok.experimental.Accessors;

/**
 * @Company lhfinance.com
 * @Author ZhaoShuai
 * @Date Create in 2019/12/11
 **/
@Data
@Accessors(chain = true)
public class Student {

    private Long id;
    private String name;
    private String age;
    private String className;
    private String teacher;
}

然后配置三要素：reader，process，writer：

package com.zs.springbatch.config;

import com.zs.springbatch.model.BatchStudent;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.NonTransientResourceException;
import org.springframework.batch.item.ParseException;
import org.springframework.batch.item.UnexpectedInputException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import tk.mybatis.mapper.common.Mapper;

import javax.annotation.PostConstruct;
import java.util.List;

/**
 * @Company lhfinance.com
 * @Author ZhaoShuai
 * @Date Create in 2019/12/11
 **/
@Component
public class Reader implements ItemReader<BatchStudent> {

    @Autowired
    private Mapper<BatchStudent> studentMapper;

    private List<BatchStudent> students;

    @PostConstruct
    public void init() {
        students = studentMapper.selectAll();
    }

    public BatchStudent read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
        if (students.size() != 0) {

            return students.remove(0);
        }
        return null;
    }
}

package com.zs.springbatch.config;

import com.zs.springbatch.model.BatchClass;
import com.zs.springbatch.model.BatchStudent;
import com.zs.springbatch.model.Student;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import tk.mybatis.mapper.common.Mapper;

/**
 * @Company lhfinance.com
 * @Author ZhaoShuai
 * @Date Create in 2019/12/11
 **/
@Component
public class Process implements ItemProcessor<BatchStudent, Student> {

    @Autowired
    private Mapper<BatchClass> classMapper;

    public Student process(BatchStudent batchStudent) throws Exception {
        Student student = new Student();
        student.setId(batchStudent.getSId())
            .setName(batchStudent.getSName())
            .setAge(batchStudent.getSAge());
        BatchClass batchClass = new BatchClass();
        batchClass.setCId(Long.valueOf(batchStudent.getSClass()));
        batchClass = classMapper.selectOne(batchClass);
        student.setClassName(batchClass.getCName())
                .setTeacher(batchClass.getCTeacher());

        return student;
    }
}

package com.zs.springbatch.config;

import com.zs.springbatch.model.Student;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.file.FlatFileItemWriter;
import org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor;
import org.springframework.batch.item.file.transform.DelimitedLineAggregator;
import org.springframework.batch.item.file.transform.ExtractorLineAggregator;
import org.springframework.batch.item.file.transform.LineAggregator;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.io.File;

/**
 * @Company lhfinance.com
 * @Author ZhaoShuai
 * @Date Create in 2019/12/11
 **/
@Component
public class Writer extends FlatFileItemWriter<Student> {

    private Resource resource = new FileSystemResource(new File("out.txt"));

    @PostConstruct
    public void init() {
        setResource(resource);
        setLineSeparator("
");
        setLineAggregator((student)->  new StringBuffer()
                .append(student.getId() + "|")
                    .append(student.getName() + "|")
                    .append(student.getAge() + "|")
                    .append(student.getClassName() + "|")
                    .append(student.getTeacher()).toString()
        );
    }
}

配置spring配置文件：

<?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:context="http://www.springframework.org/schema/context"
       xmlns:batch="http://www.springframework.org/schema/batch"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <context:component-scan base-package="com.zs.springbatch.config"/>

    <bean id="jobLauncher" class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
        <property name="jobRepository" ref="jobRepository"/>
    </bean>

    <bean id="jobRepository" class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
        <property name="transactionManager" ref="transactionManager"/>
    </bean>
    <bean id="transactionManager" class="org.springframework.batch.support.transaction.ResourcelessTransactionManager"/>

    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///batch"/>
        <property name="username" value="root"/>
        <property name="password" value="123456"/>
    </bean>

    <bean class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:mapper/*.xml"/>
    </bean>

    <bean class="tk.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.zs.springbatch.mapper"/>
    </bean>
    <batch:job id="job" job-repository="jobRepository">
        <batch:step id="step1" >
            <batch:tasklet>
                <batch:chunk writer="writer" reader="reader" processor="process"
                             processor-transactional="true" commit-interval="2"/>
            </batch:tasklet>
        </batch:step>
    </batch:job>

</beans>

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersInvalidException;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
import org.springframework.batch.core.repository.JobRestartException;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @Company lhfinance.com
 * @Author ZhaoShuai
 * @Date Create in 2019/12/12
 **/
public class TestDemo {

    public static void main(String[] args) {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("application.xml");
        Job job = context.getBean(Job.class);
        JobLauncher jobLauncher = context.getBean(JobLauncher.class);
        try {
            JobExecution run = jobLauncher.run(job, new JobParameters());
            System.out.println(run);
        } catch (JobExecutionAlreadyRunningException e) {
            e.printStackTrace();
        } catch (JobRestartException e) {
            e.printStackTrace();
        } catch (JobInstanceAlreadyCompleteException e) {
            e.printStackTrace();
        } catch (JobParametersInvalidException e) {
            e.printStackTrace();
        }
    }
}

运行测试：

可以看到当前文件夹主目录下多了一个out.txt，打开可以看到：

1|张三|18|计算机科学与技术|张涛
2|lisi|20|商务英语|王二
3|wanger|18|计算机科学与技术|张涛

这就是程序运行的结果，将student表和class表的数据信息都加载出来存入一个文件里，同样的还可以反过来，读取文件存入数据库，有兴趣可以自行尝试