Reading from a database

This recipe shows you how to read data from a database as part of a read/process/write step.

Getting ready

Each user will be read from the database. Make sure that the user database table exists with some data in it:

CREATE TABLE user  (
    id BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  first_name TEXT,
  age INT
);

For each user row in the database, we'll create a User object. Make sure that the User class exists:

public class User {
  private String firstName;
  private int age;

Make sure that the Datasource bean is defined with the database connection information.

How to do it…

Add a reader() method returning JdbcCursorItemReader-a class provided by Spring Batch:

@Bean
@StepScope
public JdbcCursorItemReader<User> reader() {
  JdbcCursorItemReader<User> reader = new JdbcCursorItemReader<User>();
  reader.setDataSource(dataSource());

  reader.setSql("SELECT first_name, age FROM user");

  reader.setRowMapper(new BeanPropertyRowMapper<User>(User...