src_main_java_com_example_demo_DemoApplication.java

package com.example.demo;

import org.seasar.doma.jdbc.Result;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        ConfigurableApplicationContext context = SpringApplication.run(DemoApplication.class, args);
        EmployeeDao dao = context.getBean(EmployeeDao.class);
        Result<Employee> result = dao.insert(new Employee(ID.notAssigned(), "test"));
        System.out.println(result.getEntity().getId());
    }
}

src_main_java_com_example_demo_Employee.java

package com.example.demo;

import org.seasar.doma.*;

@Table(name = "employee")
@Entity(immutable = true)
public class Employee {

    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Id
    private final ID<Employee> id;
    @Column(name = "name")
    private final String name;

    public Employee(ID<Employee> id, String name) {
        this.id = id;
        this.name = name;
    }

    public ID<Employee> getId() {
        return id;
    }

    public String getName() {
        return name;
    }
}

src_main_java_com_example_demo_EmployeeDao.java

package com.example.demo;

import org.seasar.doma.Dao;
import org.seasar.doma.Insert;
import org.seasar.doma.boot.ConfigAutowireable;
import org.seasar.doma.jdbc.Result;

@ConfigAutowireable
@Dao
public interface EmployeeDao {

    @Insert
    Result<Employee> insert(Employee employee);
}

src_main_java_com_example_demo_ID.java

package com.example.demo;

import org.seasar.doma.Domain;

import java.io.Serializable;
import java.util.Objects;

/**
 * EntityのIDを表すクラスです
 * @param <T> Entityの型
 */
@Domain(valueType = long.class, factoryMethod = "of")
public final class ID<T> implements Serializable {
    private static final long serialVersionUID = 1L;
    private final long value;
    private static final ID<Object> NOT_ASSIGNED = new ID<>(-1);

    private ID(long value) {
        this.value = value;
    }

    public Long getValue() {
        if (this == NOT_ASSIGNED) {
            return null;
        }
        return value;
    }

    /**
     * IDを作るstatic factoryです。
     * 0より小さいidでは生成することは出来ません。
     * @param value id
     * @param <R> Entityの型
     * @return 生成されたID
     * @throws IllegalArgumentException 0より小さいidを指定した時
     */
    public static <R> ID<R> of(final long value) {
        if (value < 0) {
            throw new IllegalArgumentException("Illegal id: " + value);
        }
        return new ID<>(value);
    }

    /**
     * 未割り当てのIDを表すIDインスタンスを返します。
     * @param <R> Entityの型
     * @return 未割り当てを表すIDインスタンス
     */
    @SuppressWarnings("unchecked")
    public static <R> ID<R> notAssigned() {
        return (ID<R>) NOT_ASSIGNED;
    }

    @Override
    public boolean equals(Object o) {
        if (this == NOT_ASSIGNED) return false; //NOT_ASSIGNEDは常に等しくない
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        ID<?> id = (ID<?>) o;
        return value == id.value;
    }

    @Override
    public int hashCode() {
        return Objects.hash(value);
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("ID{");
        sb.append("value=").append(value);
        sb.append('}');
        return sb.toString();
    }
}

src_main_resources_application.properties

spring.thymeleaf.cache=false
doma.dialect=sqlite
spring.datasource.url=jdbc:sqlite:database.sqlite
spring.datasource.driver-class-name=org.sqlite.JDBC
spring.messages.encoding=UTF-8

src_main_resources_scheme.sql

CREATE TABLE employee(
  id INTEGER PRIMARY KEY AUTOINCREMENT,
  name TEXT NOT NULl
);