通过Spring batch的官方文档，学习springbatch, 记录每个实列。
本案例是官方提供的第一个入门实列
官方文档地址
https://spring.io/guides/gs/batch-processing/#scratch
源码地址
https://gitee.com/bseaworkspace/study_java_web/tree/master/springbatchdemobasic
代码结构
业务数据
Typically, your customer or a business analyst supplies a spreadsheet. For this simple example, you can find some made-up data in src/main/resources/sample-data.csv:
比如用户提供了一个需要处理的表格数据。
Jill,Doe
Joe,Doe
Justin,Doe
Jane,Doe
John,Doe
这个表格数据 每一行包含了 名和姓 并且用逗号隔开。
接下来，我们需要准备一个sql 用来创建需要的数据表 src/main/resources/schema-all.sql:
DROP TABLE people IF EXISTS;
CREATE TABLE people (
person_id BIGINT IDENTITY NOT NULL PRIMARY KEY,
first_name VARCHAR(20),
last_name VARCHAR(20)
);
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开始代码实现
设置Maven的pom文件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.3</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>batch-processing</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>batch-processing</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-batch</artifactId>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</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>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>业务实体类
Now that you can see the format of data inputs and outputs, you can write code to represent a row of data, as the following example shows:
用来定义数据的输入和输出的格式，一个实体类的对象，就对于前面表格数据的一行数据。
package com.xsz.entity;
public class Person {
private String lastName;
private String firstName;
public Person() {
}
public Person(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
@Override
public String toString() {
return "firstName: " + firstName + ", lastName: " + lastName;
}
}
Create an Intermediate Processor 创建中间处理类
A common paradigm in batch processing is to ingest data, transform it, and then pipe it out somewhere else. Here, you need to write a simple transformer that converts the names to uppercase. The following listing
这个中间处理类，主要是把输入对象的姓名属性的值，转换成大写。
package com.xsz.processor;
import com.xsz.entity.Person;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.batch.item.ItemProcessor;
public class PersonItemProcessor implements ItemProcessor<Person, Person> {
private static final Logger log = LoggerFactory.getLogger(PersonItemProcessor.class);
@Override
public Person process(final Person person) throws Exception {
final String firstName = person.getFirstName().toUpperCase();
final String lastName = person.getLastName().toUpperCase();
final Person transformedPerson = new Person(firstName, lastName);
log.info("Converting (" + person + ") into (" + transformedPerson + ")");
return transformedPerson;
}
}