Spring batch item writer rest API

Question

Is it possible to read data from DB, process it and in ItemWriter send to another system using RestAPI (REST TEMPLATE) in Spring batch project? All I can see is fetch data and write it in a csv file.

Answer 1

It is possible to create your own custom ItemWriter.

In your case, please add the spring-boot-starter-web dependency to either your pom.xml or build.gradle

Example:

package com.example.batch;

import lombok.extern.log4j.Log4j2;
import org.springframework.batch.item.ItemWriter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

import java.util.List;

@Log4j2
public class RestItemWriter implements ItemWriter<String> {
    @Autowired
    RestTemplate restTemplate;

    public RestItemWriter(RestTemplate restTemplate) {
        this.restTemplate = restTemplate;
    }

    @Override
    public void write(List<? extends String> items) throws Exception {
        ResponseEntity<Users> users = restTemplate.getForEntity("https://jsonplaceholder.typicode.com/users/1", Users.class);

        log.info("Status code is: " + users.getStatusCode());
    }
}


package com.example.batch;

import com.fasterxml.jackson.annotation.JsonInclude;
import lombok.Getter;
import lombok.Setter;

@Getter
@Setter
@JsonInclude(JsonInclude.Include.NON_NULL)
public class Users {

    public String id;
    public String name;
    public String username;
    public String email;
    public String phone;
}

More information about custom item writers here