Spring batch 로 CSV(액셀) 만들기

Spring batch 로 CSV(액셀) 만들기

를 사용하여 CSV 데이터를 작성하는 방법을 배웁니다 [FlatFileItemWriter](https://docs.spring.io/spring-batch/4.0.x/api/org/springframework/batch/item/file/FlatFileItemWriter.html). 파일이나 스트림에 데이터를 쓰는 항목 작성기입니다. 출력 파일의 위치는 a로 정의되며 Resource쓰기 가능한 파일을 나타내야합니다.

프로젝트 구조

이 프로젝트에서는 –

1. 를 input/*.csvMultiResourceItemReader

   사용하여 3 개의 CSV 파일을 읽습니다

   .

2. 를 output/outputData.csvFlatFileItemWriter

   사용하여 전체 데이터를 파일에 씁니다

   .

프로젝트 구조

FlatFileItemWriter로 데이터 CSV 파일 쓰기

FlatFileItemWriterCSV 파일에서 읽은 줄을 쓰는 데 사용해야 합니다. Resource전달 된 writer.setResource()메소드에 내용을 씁니다 .

package com.howtodoinjava.demo.config;

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.core.launch.support.RunIdIncrementer;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.FlatFileItemWriter;
import org.springframework.batch.item.file.MultiResourceItemReader;
import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor;
import org.springframework.batch.item.file.transform.DelimitedLineAggregator;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.FileSystemResource;
import org.springframework.core.io.Resource;

import com.howtodoinjava.demo.model.Employee;

@Configuration
@EnableBatchProcessing
public class BatchConfig 
{
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Value("input/inputData*.csv")
    private Resource[] inputResources;

    private Resource outputResource = new FileSystemResource("output/outputData.csv");

    @Bean
    public FlatFileItemWriter<Employee> writer() 
    {
        //Create writer instance
        FlatFileItemWriter<Employee> writer = new FlatFileItemWriter<>();

        //Set output file location
        writer.setResource(outputResource);

        //All job repetitions should "append" to same output file
        writer.setAppendAllowed(true);

        //Name field values sequence based on object properties 
        writer.setLineAggregator(new DelimitedLineAggregator<Employee>() {
            {
                setDelimiter(",");
                setFieldExtractor(new BeanWrapperFieldExtractor<Employee>() {
                    {
                        setNames(new String[] { "id", "firstName", "lastName" });
                    }
                });
            }
        });
        return writer;
    }

    @Bean
    public Job readCSVFilesJob() {
        return jobBuilderFactory
                .get("readCSVFilesJob")
                .incrementer(new RunIdIncrementer())
                .start(step1())
                .build();
    }

    @Bean
    public Step step1() {
        return stepBuilderFactory.get("step1").<Employee, Employee>chunk(5)
                .reader(multiResourceItemReader())
                .writer(writer())
                .build();
    }

    @Bean
    public MultiResourceItemReader<Employee> multiResourceItemReader() 
    {
        MultiResourceItemReader<Employee> resourceItemReader = new MultiResourceItemReader<Employee>();
        resourceItemReader.setResources(inputResources);
        resourceItemReader.setDelegate(reader());
        return resourceItemReader;
    }

    @SuppressWarnings({ "rawtypes", "unchecked" })
    @Bean
    public FlatFileItemReader<Employee> reader() 
    {
        //Create reader instance
        FlatFileItemReader<Employee> reader = new FlatFileItemReader<Employee>();

        //Set number of lines to skips. Use it if file has header rows.
        reader.setLinesToSkip(1);   

        //Configure how each line will be parsed and mapped to different values
        reader.setLineMapper(new DefaultLineMapper() {
            {
                //3 columns in each row
                setLineTokenizer(new DelimitedLineTokenizer() {
                    {
                        setNames(new String[] { "id", "firstName", "lastName" });
                    }
                });
                //Set values in Employee class
                setFieldSetMapper(new BeanWrapperFieldSetMapper<Employee>() {
                    {
                        setTargetType(Employee.class);
                    }
                });
            }
        });
        return reader;
    }
}

public class Employee {

    String id;
    String firstName;
    String lastName;

    //public setter and getter methods
}

inputData1.csv

id,firstName,lastName
1,Lokesh,Gupta
2,Amit,Mishra
3,Pankaj,Kumar
4,David,Miller

inputData2.csv

id,firstName,lastName
5,Ramesh,Gupta
6,Vineet,Mishra
7,Amit,Kumar
8,Dav,Miller

inputData3.csv

id,firstName,lastName
9,Vikas,Kumar
10,Pratek,Mishra
11,Brian,Kumar
12,David,Cena

메이븐 의존성

프로젝트 의존성을 살펴보십시오.

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd;
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.howtodoinjava</groupId>
    <artifactId>App</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>App</name>
    <url>http://maven.apache.org</url>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.3.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-batch</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>repository.spring.release</id>
            <name>Spring GA Repository</name>
            <url>http://repo.spring.io/release</url>
        </repository>
    </repositories>
</project>

데모

애플리케이션을 실행하기 전에 App.java애플리케이션을 스프링 부트 애플리케이션으로 실행하는 전체 코드를 살펴보십시오 .

package com.howtodoinjava.demo;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

@SpringBootApplication
@EnableScheduling
public class App
{
    @Autowired
    JobLauncher jobLauncher;

    @Autowired
    Job job;

    public static void main(String[] args)
    {
        SpringApplication.run(App.class, args);
    }

    @Scheduled(cron = "0 */1 * * * ?")
    public void perform() throws Exception
    {
        JobParameters params = new JobParametersBuilder()
                .addString("JobID", String.valueOf(System.currentTimeMillis()))
                .toJobParameters();
        jobLauncher.run(job, params);
    }
}

application.properties

#Disable batch job's auto start 
spring.batch.job.enabled=false

spring.main.banner-mode=off

응용 프로그램을 실행

애플리케이션을 스프링 부트 애플리케이션으로 실행하고 콘솔을 확인하십시오. 배치 작업은 1 분마다 시작됩니다. 입력 파일을 읽고 콘솔에서 읽은 값을 인쇄합니다.

1,Lokesh,Gupta
2,Amit,Mishra
3,Pankaj,Kumar
4,David,Miller
5,Ramesh,Gupta
6,Vineet,Mishra
7,Amit,Kumar
8,Dav,Miller
9,Vikas,Kumar
10,Pratek,Mishra
11,Brian,Kumar
12,David,Cena

의견 섹션에 질문을 남겨주세요.

참고

https://howtodoinjava.com/spring-batch/flatfileitemwriter-write-to-csv-file/