开源软件名称：

spring-data-ebean

开源软件地址：

https://gitee.com/hexagonframework/spring-data-ebean

开源软件介绍：

spring-data-ebean

Ebean implementation for spring data.

MAVEN中央仓库链接

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Spring Data项目的主要目标是使构建使用DDD仓储接口与实现的Spring应用程序变得更加容易。此模块是基于Ebean ORM（轻量级JPA）的仓储层实现。通过使用此模块，你可以在基于Ebean ORM下使用Spring Data模式带来的便利性。如果你还没有接触过Spring Data或Ebean ORM，建议先了解下该项目。

支持的一些特性

对标准Entity支持完整CRUD操作，包括常用的查询操作
支持通过接口中的注解生成对应的查询（orm查询、sql查询、命名orm查询、命名sql查询、dto查询）
支持通过接口中的方法名生成对应的查询
支持QueryChannel服务，用于CQRS
提供基础属性的实体基类和面向领域编程DDD基类
原生支持使用注解实现审计（如创建人、创建时间、修改人、最后修改时间)
支持自定义编写基于Ebean的查询，方便而不失灵活性
方便的与Spring集成
支持MySQL、Oracle、SQL Server、H2、PostgreSQL等数据库

实现的场景

基于主键获取单个实体
根据条件获取实体的列表
保存新的单个实体并返回主键
批量插入相同类型的多个实体并返回生成的主键列表
更新单个现有实体——同时更新所有的实体字段
获取多对一关系(部门的所属公司)
获取一对多关系(公司的部门)
更新实体一对多的关系(公司的部门)-增加两个项目，更新两个项目和删除一个项目-所有只需一句代码/一次操作
复杂的选择-构造选择的条件基于一些布尔条件+加入一些连接
使用JDBC简单语句(非PreparedStatement)执行查询
基于主键移除单个实体

为什么选择Ebean ORM

基于JPA注解的轻量级ORM实现，支持Mybatis不支持的实体关联，但相比Hibernate/JPA具有Mybatis的查询灵活性，支持查询partial objects。对于实现领域模型仓储接口的聚合根实体保存(保存聚合根实体同时保存聚合根上的关联实体、值对象)和partial objects等技术要求，Ebean都非常适用。

我选择关系型数据持久化框架的基本原则:

拥抱SQL而非隐藏
可以实现面向领域编程
可以利用JPA注解，但不能是JPA的完整实现（这点我偏向于Ebean）
足够成熟以应对企业级应用（Ebean和Hibernate同时期作品，资格老，而且持续更新以满足更高需求）

框架优缺点比较

参考：java-persistence-frameworks-comparison

Hibernate/JPA

Compare to JPA
反正比Hibernate/JPA好

JDBC Template

优点
- 感觉自己非常接近JDBC本身
- 实现了所有的场景而没有更大的问题-没有隐藏的惊喜
- 非常容易的批量操作
- 设置简单
缺点
- 在Java代码中内联SQL使得实现仓储接口的可读性不强。如果Java支持多行字符串，那就更好了
- 调试日志可以更好

jOOQ

优点
- 非常流畅，很容易编写新的查询，代码非常易读
- 一旦设置好，就很容易使用，非常适合简单的查询
- 很棒的日志记录器调试输出
缺点
- 某些数据库的付费许可证——很难说服经理们相信它是值得的:)
- 对于大的查询来说没有那么多的实用性——最好使用原生SQL(参见场景9)
- 批量操作的怪异语法(如果您不使用UpdatableRecord)。但这没什么大不了的……

MyBatis

优点
- 在XML映射文件里写SQL语句很爽
缺点
- 实现一个DAO、仓储要写很多文件（DAO/Repository、XXXMapper、XXXMapper.xml），方法多了比较繁琐
- 无法在一个方法里做批处理，无法级联加载
- 即使是简单的CRUD，都显得繁琐，导致存在各种弥补mybatis这一缺陷的第三方封装框架
- 无法面向对象，无法实现DDD

EBean

优点
- 所有场景都实现非常完美，代码可读性高
- 实现批处理超级简单
- ORM查询、sql查询、DTO查询都非常简单
缺点
- DTO查询功能较新，有待增加XML mapping对DTO的支持
- 必须“增强”实体，但实际上它基本上只是关于环境的设置(IDE插件和Gradle插件)，然后你就不用去想它了。

快速开始

建立maven项目，建议使用spring boot和spring-data-ebean-spring-boot建立web项目

实例：spring-boot-data-ebean-samples

1、创建一个表格实体类或SQL实体类或DTO类:

表格实体：

@Entity@Getter@Setterpublic class User {  @Id  @GeneratedValue  private Integer id;  private String firstname;  private String lastname;  @Column(nullable = false, unique = true) private String emailAddress;}

SQL实体：

Sql实体：

@Entity@Sql@Getter@Setterpublic class UserInfo {  private String firstName;  private String lastName;  private String emailAddress;}

POJO DTO：

@Getter@Setterpublic class UserDTO {  private String firstName;  private String lastName;  private String emailAddress;}

2、创建一个仓储接口

public interface UserRepository extends EbeanRepository<User, Long> {    @Query("where emailAddress = :emailAddress order by id desc")    User findUserByEmailAddressEqualsOql(@Param("emailAddress") String emailAddress);    /**     *  select fetch query细粒度控制查询字段     */    @Query("select (firstname,lastname,address) fetch manager (lastname) where lastname = :lastname order by id desc")    List<User> findByLastnameOql(@Param("lastname") String lastname);    @Query(nativeQuery = true, value = "select * from user where email_address = :emailAddress order by id desc")    User findUserByEmailAddressEquals(@Param("emailAddress") String emailAddress);    @Query(nativeQuery = true, value = "select * from user where lastname = :lastname order by id desc")    List<User> findUsersByLastnameEquals(@Param("lastname") String lastname);    @Query(nativeQuery = true, value = "update user set email_address = :newEmail where email_address = :oldEmail")    @Modifying    int changeUserEmailAddress(@Param("oldEmail") String oldEmail, @Param("newEmail") String newEmail);    @Query("delete from user where emailAddress = :emailAddress")    @Modifying    int deleteUserByEmailAddressOql(@Param("emailAddress") String emailAddress);    @Query(nativeQuery = true, value = "delete from user where email_address = :emailAddress")    @Modifying    int deleteUserByEmailAddress(@Param("emailAddress") String emailAddress);    /**     * 命名ORM/SQL查询      */    @Query(name = "withManagerById")    List<User> findByLastnameNamedOql(@Param("lastname") String lastname);        List<User> findAllByEmailAddressAndLastname(@Param("emailAddress") String emailAddress, @Param("lastname") String lastname);}

3、对于使用到的命名sql查询、命名orm查询，编写XML文件：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><ebean xmlns="http://ebean-orm.github.io/xml/ns/ebean">    <entity class="org.springframework.data.ebean.sample.domain.User">        <named-query name="withManagerById">            <query>                select (firstname,lastname,address)                fetch manager (lastname)                where lastname = :lastname order by id desc            </query>        </named-query>        <raw-sql name="byEmailAddressEquals">            <query>                select * from user                where email_address = :emailAddress                order by id desc            </query>        </raw-sql>    </entity>    <entity class="org.springframework.data.ebean.sample.domain.UserInfo">        <raw-sql name="userInfo">            <query>                select first_name, last_name, email_address from user            </query>        </raw-sql>        <raw-sql name="userInfoByEmail">            <query>                select first_name, last_name, email_address from user                where email_address = :emailAddress                order by id desc            </query>        </raw-sql>    </entity></ebean>

4、编写你的使用代码:

UserRepositoryIntegrationTests.java

@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes = SampleConfig.class)public class UserRepositoryIntegrationTests {    @Autowired    UserRepository repository;    @Test    public void sampleTestCase() {        User user = new User("Xuegui", "Yuan", "[email protected]");        user.setAge(29);        user = repository.save(user);        List<User> result1 = (List<User>) repository.findAll();        result1.forEach(it -> System.out.println(it));        assertEquals(1, result1.size());        assertEquals("Yuan", result1.get(0).getLastname());        assertThat(result1, hasItem(user));        List<User> result2  = repository.findByLastnameOql("Yuan");        assertEquals(1, result2.size());        assertEquals("Yuan", result2.get(0).getLastname());        assertThat(result2, hasItem(user));        List<User> result3 = repository.findUsersByLastnameEquals("Yuan");        assertEquals(1, result3.size());        assertEquals("Yuan", result3.get(0).getLastname());        User result4 = repository.findUserByEmailAddressEqualsOql("[email protected]");        assertEquals("[email protected]", result4.getEmailAddress());        User result5 = repository.findUserByEmailAddressEquals("[email protected]");        assertEquals("[email protected]", result5.getEmailAddress());        int result6 = repository.changeUserEmailAddress("[email protected]", "[email protected]");        assertEquals(1, result6);        List<User> result7  = repository.findByLastnameOql("Yuan");        assertEquals("[email protected]", result7.get(0).getEmailAddress());        int result8 = repository.deleteUserByEmailAddress("[email protected]");        assertEquals(1, result8);        User result9 = repository.findUserByEmailAddressEquals("[email protected]");        assertNull(result9);        user = new User("Xuegui", "Yuan", "[email protected]");        user.setAge(29);        user = repository.save(user);        User result10 = repository.findUserByEmailAddressEquals("[email protected]");        assertNotNull(result10);        int result11 = repository.deleteUserByEmailAddressOql("[email protected]");        assertEquals(1, result11);        User result12 = repository.findUserByEmailAddressEquals("[email protected]");        assertNull(result12);    }    @Test    public void testFindByExample() {        User u = new User();        u.setEmailAddress("YUANXUEGUI");        List<User> result1 = repository.findAll(Example.of(u, ExampleMatcher.matchingAll()                .withIgnoreCase(true)                .withStringMatcher(ExampleMatcher.StringMatcher.CONTAINING)));        assertEquals(1, result1.size());        assertEquals("Yuan", result1.get(0).getLastname());        assertThat(result1, hasItem(user));        List<User> result2 = repository.findAll(Example.of(u, ExampleMatcher.matchingAll()                .withIgnoreCase(false)                .withStringMatcher(ExampleMatcher.StringMatcher.EXACT)));        assertEquals(0, result2.size());    }}

查询对象 UserQuery

@Data@IncludeFields("emailAddress,fullName(lastName,firstName),age")public class UserQuery {    @ExprParam(expr = ExprType.CONTAINS)    private String emailAddress;    @ExprParam(name = "age", expr = ExprType.GE)    private int ageStart;    @ExprParam(name = "age", expr = ExprType.LE)    private int ageEnd;}

EbeanQueryChannelServiceIntegrationTests.java

package org.springframework.data.ebean.querychannel;import io.ebean.Query;import org.junit.Before;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.ebean.sample.config.SampleConfig;import org.springframework.data.ebean.sample.domain.User;import org.springframework.data.ebean.sample.domain.UserInfo;import org.springframework.data.ebean.sample.domain.UserRepository;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import java.util.HashMap;import java.util.Map;import static org.junit.Assert.assertEquals;/** * @author Xuegui Yuan */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes = SampleConfig.class)public class EbeanQueryChannelServiceIntegrationTests {    // Test fixture    User user;    @Autowired    private EbeanQueryChannelService ebeanQueryChannelService;    @Autowired    private UserRepository repository;    @Before    public void initUser() {        repository.deleteAll();        user = new User("QueryChannel", "Test", "[email protected]");        user.setAge(29);        user = repository.save(user);    }    @Test    public void createSqlQueryMappingColumns() {        String sql1 = "select first_name, last_name, email_address from user where last_name= :lastName";        String sql2 = "select first_name as firstName, last_name as lastName, email_address as emailAddress from user where last_name= :lastName";        Map<String, String> columnsMapping = new HashMap<>();        columnsMapping.put("first_name", "firstName");        columnsMapping.put("last_name", "lastName");        Query<UserInfo> query1 = ebeanQueryChannelService.createSqlQuery(UserInfo.class,                sql1);        Query<UserInfo> query2 = ebeanQueryChannelService.createSqlQuery(UserInfo.class,                sql2);        Query<UserInfo> query3 = ebeanQueryChannelService.createSqlQueryMappingColumns(UserInfo.class,                sql1, columnsMapping);        query1.setParameter("lastName", "Test");        query2.setParameter("lastName", "Test");        query3.setParameter("lastName", "Test");        UserInfo userInfo1 = query1.findOne();        UserInfo userInfo2 = query2.findOne();        UserInfo userInfo3 = query3.findOne();        assertEquals("QueryChannel", userInfo1.getFirstName());        assertEquals("[email protected]", userInfo1.getEmailAddress());        assertEquals("QueryChannel", userInfo2.getFirstName());        assertEquals("[email protected]", userInfo2.getEmailAddress());        assertEquals("QueryChannel", userInfo3.getFirstName());        assertEquals("[email protected]", userInfo3.getEmailAddress());    }    @Test    public void createNamedQuery() {        UserInfo userInfo = ebeanQueryChannelService.createNamedQuery(UserInfo.class,                "userInfoByEmail").setParameter("emailAddress",                "[email protected]").findOne();        assertEquals("QueryChannel", userInfo.getFirstName());        assertEquals("[email protected]", userInfo.getEmailAddress());    }    @Test    public void createNamedQueryWhere() {        UserInfo userInfo = ebeanQueryChannelService.createNamedQuery(UserInfo.class,                "userInfo").where()                .eq("emailAddress", "[email protected]").findOne();        assertEquals("QueryChannel", userInfo.getFirstName());        assertEquals("[email protected]", userInfo.getEmailAddress());    }    @Test    public void createDtoQuery() {        String sql = "select first_name, last_name, email_address from user where email_address = :emailAddress";        UserDTO userDTO = ebeanQueryChannelService.createDtoQuery(UserDTO.class, sql)                .setParameter("emailAddress", "[email protected]")                .findOne();        assertEquals("QueryChannel", userDTO.getFirstName());        assertEquals("[email protected]", userDTO.getEmailAddress());    }        @Test    public void query_queryObject() {        UserQuery userQuery = new UserQuery();        userQuery.setEmailAddress("[email protected]");        userQuery.setAgeStart(1);        userQuery.setAgeEnd(30);        UserDTO user = queryChannel.createQuery(User.class, userQuery)                .asDto(UserDTO.class)                .setRelaxedMode()                .findOne();        assertEquals("[email protected]", user.getEmailAddress());    }        @Test    public void applyQueryObject() {        UserQuery userQuery = new UserQuery();        userQuery.setEmailAddress("[email protected]");        userQuery.setAgeStart(1);        userQuery.setAgeEnd(30);        UserInfo userInfo = EbeanQueryChannelService.applyWhere(queryChannel.createNamedQuery(UserInfo.class,                "userInfo").where(), userQuery).findOne();        assertEquals("QueryChannel", userInfo.getFirstName());        assertEquals("[email protected]", userInfo.getEmailAddress());    }}