Spring Batch教程（六）spring boot实现batch功能注解示例：读文件写入mysql

Spring batch 系列文章

Spring Batch教程（一） 简单的介绍以及通过springbatch将xml文件转成txt文件
Spring Batch教程（二）示例：将txt文件转成xml文件以及读取xml文件内容存储到数据库mysql
Spring Batch教程（三）示例：从mysql中读取数据写入文本和从多个文本中读取内容写入mysql
Spring Batch教程（四）tasklet使用示例：spring batch的定时任务使用
Spring Batch教程（五）spring boot实现batch功能注解示例：读写文本文件
Spring Batch教程（六）spring boot实现batch功能注解示例：读文件写入mysql

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本文是以注解的方式实现了读取文本数据，求和后存储至mysql。
本文使用的是jdk8，较高版本的spring batch需要jdk11环境。

一、示例：读文本文件内容，求和计算后写入mysql

1、maven依赖

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-batch</artifactId>
			<version>2.3.12.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<version>1.18.2</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>5.1.31</version>
		</dependency>
		<dependency>
			<groupId>com.mchange</groupId>
			<artifactId>c3p0</artifactId>
			<version>0.9.5-pre8</version>
		</dependency>

2、java bean

1）、Student

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * 
 * @author alanchan
 *
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student {
	private String id;
	private int chinese;
	private int math;
	private int english;

}

2）、StudentTotalScore

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

/**
 * 
 * @author alanchan
 *
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class StudentTotalScore {
	private String id;
	private int totalScore;

}

3、配置spring batch的ItemReader、ItemWriter和ItemProcessor

import java.beans.PropertyVetoException;

import javax.sql.DataSource;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.database.BeanPropertyItemSqlParameterSourceProvider;
import org.springframework.batch.item.database.JdbcBatchItemWriter;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.jdbc.core.JdbcTemplate;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.win.writedbbyannotation.bean.Student;
import com.win.writedbbyannotation.bean.StudentTotalScore;

/**
 * 
 * @author alanchan
 *
 */
@Configuration
@EnableBatchProcessing
public class BatchConfiguration {
	private final String inputFiles = "student-data.txt";

	@Bean
	public ItemReader<Student> reader() {
		FlatFileItemReader<Student> reader = new FlatFileItemReader<Student>();
		reader.setResource(new ClassPathResource(inputFiles));
		reader.setLineMapper(new DefaultLineMapper<Student>() {
			{
				setLineTokenizer(new DelimitedLineTokenizer() {
					{
						setNames(new String[] { "id", "chinese", "math", "english" });
					}
				});
				setFieldSetMapper(new BeanWrapperFieldSetMapper<Student>() {
					{
						setTargetType(Student.class);
					}
				});
			}
		});
		return reader;
	}

	@Bean
	public ItemWriter<StudentTotalScore> writer(DataSource dataSource) {
		JdbcBatchItemWriter<StudentTotalScore> writer = new JdbcBatchItemWriter<StudentTotalScore>();
		writer.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<StudentTotalScore>());
		writer.setSql("INSERT INTO studenttotalscore (id,totalscore) VALUES (:id,:totalScore)");
		writer.setDataSource(dataSource);
		return writer;
	}

	@Bean
	public ItemProcessor<Student, StudentTotalScore> processor() {
		return new StudentItemProcessor();
	}

	@Bean
	public Job createMarkSheet(JobBuilderFactory jobs, Step step) {
		return jobs.get("createMarkSheet").flow(step).end().build();
	}

	@Bean
	public Step step(StepBuilderFactory stepBuilderFactory, ItemReader<Student> reader, ItemWriter<StudentTotalScore> writer, ItemProcessor<Student, StudentTotalScore> processor) {
		return stepBuilderFactory.get("step").<Student, StudentTotalScore>chunk(5).reader(reader).processor(processor).writer(writer).build();
	}

	@Bean
	public JdbcTemplate jdbcTemplate(DataSource dataSource) {
		return new JdbcTemplate(dataSource);
	}

	@Bean
	public DataSource getDataSource() throws PropertyVetoException {
		ComboPooledDataSource dataSource = new ComboPooledDataSource();
		dataSource.setDriverClass("com.mysql.jdbc.Driver");
		dataSource.setJdbcUrl("jdbc:mysql://192.168.10.44:3306/test");
		dataSource.setUser("root");
		dataSource.setPassword("12345");
		return dataSource;
	}
}

4、创建ItemProcessor实现类

import org.springframework.batch.item.ItemProcessor;

import com.win.writedbbyannotation.bean.Student;
import com.win.writedbbyannotation.bean.StudentTotalScore;


/**
 * 
 * @author alanchan
 *
 */
public class StudentItemProcessor implements ItemProcessor<Student, StudentTotalScore> {

	@Override
	public StudentTotalScore process(final Student student) throws Exception {
		int totalScore = student.getChinese() + student.getMath() + student.getEnglish();
		System.out.println("student id:" + student.getId() + " and Total score:" + totalScore);

		StudentTotalScore studentTotalScore = new StudentTotalScore(student.getId(), totalScore);
		return studentTotalScore;
	}

}

5、创建一个运行job的main类

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;

import com.win.writedbbyannotation.bean.StudentTotalScore;

/**
 * 
 * @author alanchan
 *
 */

@ComponentScan
@EnableAutoConfiguration
//@SpringBootApplication
public class App {

	public static void main(String[] args) {
		ApplicationContext ctx = SpringApplication.run(App.class, args);
		List result = ctx.getBean(JdbcTemplate.class).query("select id,totalscore FROM StudentTotalScore", new RowMapper() {
			@Override
			public StudentTotalScore mapRow(ResultSet rs, int row) throws SQLException {
				return new StudentTotalScore(rs.getString(1), Integer.parseInt(rs.getString(2)));
			}
		});
		System.out.println("记录数:" + result.size());
	}

}

6、准备测试数据

在工程项目中的resources文件夹下创建student-data.txt文件，并写入如下内容

student-1,90,85,96
student-2,92,97,94
student-3,95,93,100

7、创建数据库和表

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for studenttotalscore
-- ----------------------------
DROP TABLE IF EXISTS `studenttotalscore`;
CREATE TABLE `studenttotalscore`  (
  `id` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `totalScore` int(11) NULL DEFAULT NULL
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

8、验证

启动app.java，然后观察应用程序控制台与mysql数据库中数据的变化。
在启动应用程序时可能会出现如下异常：

Table 'XXX.BATCH_JOB_INSTANCE' doesn't exist

因为Spring Batch 会启用一个 H2 数据库，在这个数据库中，Sping 会对 Batch 需要的配置进行配置。如果使用 Spring JPA 的话，需要 Spring Batch 帮你初始化表。
解决办法：
application.properties文件中增加如下配置

spring.batch.initialize-schema=ALWAYS
# 或  Spring Boot 2.7 的版本中
spring.batch.jdbc.initialize-schema=ALWAYS

1）、应用程序输出结果

控制台部分输出

 Scheduler class: 'org.quartz.core.QuartzScheduler' - running locally.
  NOT STARTED.
  Currently in standby mode.
  Number of jobs executed: 0
  Using thread pool 'org.quartz.simpl.SimpleThreadPool' - with 10 threads.
  Using job-store 'org.quartz.simpl.RAMJobStore' - which does not support persistence. and is not clustered.

2023-07-24 11:08:33.785  INFO 100012 --- [           main] org.quartz.impl.StdSchedulerFactory      : Quartz scheduler 'quartzScheduler' initialized from an externally provided properties instance.
2023-07-24 11:08:33.785  INFO 100012 --- [           main] org.quartz.impl.StdSchedulerFactory      : Quartz scheduler version: 2.2.1
2023-07-24 11:08:33.785  INFO 100012 --- [           main] org.quartz.core.QuartzScheduler          : JobFactory set to: org.springframework.scheduling.quartz.SpringBeanJobFactory@73d60e76
2023-07-24 11:08:33.804  INFO 100012 --- [           main] o.s.s.quartz.SchedulerFactoryBean        : Starting Quartz Scheduler now
2023-07-24 11:08:33.804  INFO 100012 --- [           main] org.quartz.core.QuartzScheduler          : Scheduler quartzScheduler_$_NON_CLUSTERED started.
2023-07-24 11:08:33.812  INFO 100012 --- [           main] com.win.writedbbyannotation.App          : Started App in 1.949 seconds (JVM running for 2.226)
2023-07-24 11:08:33.814  INFO 100012 --- [           main] o.s.b.a.b.JobLauncherApplicationRunner   : Running default command line with: []
2023-07-24 11:08:33.936  INFO 100012 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [FlowJob: [name=createMarkSheet]] launched with the following parameters: [{}]
2023-07-24 11:08:33.971  INFO 100012 --- [           main] o.s.batch.core.job.SimpleStepHandler     : Step already complete or not restartable, so no action to execute: StepExecution: id=1, version=3, name=step, status=COMPLETED, exitStatus=COMPLETED, readCount=3, filterCount=0, writeCount=3 readSkipCount=0, writeSkipCount=0, processSkipCount=0, commitCount=1, rollbackCount=0, exitDescription=
2023-07-24 11:08:33.979  INFO 100012 --- [           main] o.s.b.c.l.support.SimpleJobLauncher      : Job: [FlowJob: [name=createMarkSheet]] completed with the following parameters: [{}] and the following status: [COMPLETED] in 21ms
记录数:3

2）、程序功能验证

数据源文件能正常的读取到，且能针对每个学生的数据进行求和并存储至mysql中。

以上，完成了读取文本文件内容并求和、存储至mysql数据库中，是通过注解完成该项工作。