fluent-mybatis初体验

最近的项目中都是springboot jpa的框架，jpa在开发上确实是能让效率很好的提升。但是项目运行中也会有一些问题（像1对1的映射、配置单项关联，延迟加载不生效、会冗余的查出一些不需要用到的字段或其他的信息）正好也是有了一个新项目，想着能不用jpa的框架，用mybatis，有同事说到了fluent-mybatis，那自己也是先写个demo玩玩，顺带记录着。

fluent-mybatis官网https://gitee.com/fluent-mybatis/fluent-mybatis/wikis/fluent mybatis特性总览

1.搭建springboot项目

2.整合mybatis、fluent-mybatis。 pom文件如下

1.  
   <properties>
2.  
   <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
3.  
   <maven.compiler.source>1.8</maven.compiler.source>
4.  
   <maven.compiler.target>1.8</maven.compiler.target>
5.  
   <project.fluent.mybatis.version>1.9.8</project.fluent.mybatis.version>
6.  
   </properties>
7.  
    
8.  
   <dependencies>
9.  
   <dependency>
10.  
    <groupId>junit</groupId>
11.  
    <artifactId>junit</artifactId>
12.  
    <version>4.11</version>
13.  
    <!-- <scope>test</scope>-->
14.  
    </dependency>
15.  
     
16.  
    <!--添加spring-boot -->
17.  
    <dependency>
18.  
    <groupId>org.springframework.boot</groupId>
19.  
    <artifactId>spring-boot-starter-web</artifactId>
20.  
    <version>2.1.10.RELEASE</version>
21.  
    </dependency>
22.  
    <dependency>
23.  
    <groupId>org.mybatis.spring.boot</groupId>
24.  
    <artifactId>mybatis-spring-boot-starter</artifactId>
25.  
    <version>2.1.0</version>
26.  
    </dependency>
27.  
    <dependency>
28.  
    <groupId>mysql</groupId>
29.  
    <artifactId>mysql-connector-java</artifactId>
30.  
    <version>5.1.49</version>
31.  
    </dependency>
32.  
    <dependency>
33.  
    <groupId>com.github.atool</groupId>
34.  
    <artifactId>fluent-mybatis</artifactId>
35.  
    <version>${project.fluent.mybatis.version}</version>
36.  
    </dependency>
37.  
     
38.  
    <dependency>
39.  
    <groupId>com.github.atool</groupId>
40.  
    <artifactId>fluent-mybatis-processor</artifactId>
41.  
    <scope>provided</scope>
42.  
    <version>${project.fluent.mybatis.version}</version>
43.  
    </dependency>
44.  
    <dependency>
45.  
    <groupId>org.projectlombok</groupId>
46.  
    <artifactId>lombok</artifactId>
47.  
    <version>1.18.8</version>
48.  
    </dependency>
49.  
     
50.  
    </dependencies>

3.配置application.yaml文件（数据源等信息）

1.  
   spring:
2.  
   datasource:
3.  
   url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&serverTimezone=Asia/Shanghai
4.  
   username: root
5.  
   password: root
6.  
   driver-class-name: com.mysql.jdbc.Driver
7.  
    
8.  
   server:
9.  
   port: 8001
10.  
    mybatis:
11.  
    configuration:
12.  
    # 配置打印sql语句到控制台
13.  
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

项目的目录结构如下

 也是可以通过代码生成工具，完成dao、entity等类的生成。首先得自己先在库里把表建好。

1.  
   package com.freekai;
2.  
    
3.  
   import cn.org.atool.generator.FileGenerator;
4.  
   import cn.org.atool.generator.annotation.Relation;
5.  
   import cn.org.atool.generator.annotation.RelationType;
6.  
   import cn.org.atool.generator.annotation.Table;
7.  
   import cn.org.atool.generator.annotation.Tables;
8.  
   import com.freekai.custom.FreekaiMapper;
9.  
   import org.junit.Test;
10.  
     
11.  
    public class EntityGenerator {
12.  
    //数据源url
13.  
    static final String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&serverTimezone=Asia/Shanghai";
14.  
     
15.  
    //数据库用户名
16.  
    static final String username = "root";
17.  
     
18.  
    //数据库密码
19.  
    static final String password = "root";
20.  
     
21.  
    @Test
22.  
    public void generate() throws Exception {
23.  
    //引用配置类，build方法允许有多个配置类
24.  
    FileGenerator.build(Empty.class);
25.  
    }
26.  
     
27.  
    @Tables(
28.  
    //设置数据库连接信息
29.  
    url = url,username = username,password = password,
30.  
    driver = "com.mysql.jdbc.Driver",
31.  
    //设置entity类生成src目录，相对于user.dir
32.  
    srcDir = "src/main/java",
33.  
    //设置entity类的package值
34.  
    basePack = "com.freekai.fluent",
35.  
    //设置dao接口和实现的src目录，相对于user.dir
36.  
    daoDir = "src/main/java",
37.  
    //设置哪些表要生成Entity文件
38.  
    tables = {@Table(value = {"user_test_address","user_test"}, logicDeleted = "is_delete", superMapper = FreekaiMapper.class)},
39.  
    relations = {
40.  
    @Relation(method = "findAddressV2", source = "user_test", target = "user_test_address", type = RelationType.OneWay_0_1
41.  
    , where = "id=user_test_id"),
42.  
    @Relation(method = "findUserTestV2", source = "user_test_address", target = "user_test", type = RelationType.OneWay_0_1)
43.  
    }
44.  
    )
45.  
    static class Empty{ //类名随便取，只是配置定义的一个载体
46.  
     
47.  
    }
48.  
     
49.  
    }

上面的tables中 user_test_address  user_test两张表配置了 1对1的映射。和hibernate中的@OneToOne含义一致。

另外也指定了逻辑删除的字段是is_delete。

细心的朋友会发现还有一个@Relation的配置。 method： findAddressV2即相当于会在生成的实体类中生成一个findAddressV2这个方法，这个方法的返回值是对应的关联表的实体类。where="id=user_test_id" 和source及target组合起来后，相当于 user_test.id = user_test_address.user_test_id (即在user_test_address表中有一个user_test_id字段，存储的是user_test表的id值),源码中也有注释。

另一个@Relation同理，反着配置一下就可以了。 执行上述代码中的generate()方法，可以发现目录下有生成的文件。

 UserTestEntity.java

1.  
   package com.freekai.fluent.entity;
2.  
    
3.  
   import cn.org.atool.fluent.mybatis.annotation.FluentMybatis;
4.  
   import cn.org.atool.fluent.mybatis.annotation.LogicDelete;
5.  
   import cn.org.atool.fluent.mybatis.annotation.RefMethod;
6.  
   import cn.org.atool.fluent.mybatis.annotation.TableField;
7.  
   import cn.org.atool.fluent.mybatis.annotation.TableId;
8.  
   import cn.org.atool.fluent.mybatis.base.RichEntity;
9.  
   import com.freekai.custom.FreekaiMapper;
10.  
    import java.util.Date;
11.  
    import lombok.AllArgsConstructor;
12.  
    import lombok.Data;
13.  
    import lombok.EqualsAndHashCode;
14.  
    import lombok.NoArgsConstructor;
15.  
    import lombok.experimental.Accessors;
16.  
     
17.  
    /**
18.  
    * UserTestEntity: 数据映射实体定义
19.  
    *
20.  
    * @author Powered By Fluent Mybatis
21.  
    */
22.  
    @SuppressWarnings({"rawtypes", "unchecked"})
23.  
    @Data
24.  
    @Accessors(
25.  
    chain = true
26.  
    )
27.  
    @EqualsAndHashCode(
28.  
    callSuper = false
29.  
    )
30.  
    @AllArgsConstructor
31.  
    @NoArgsConstructor
32.  
    @FluentMybatis(
33.  
    table = "user_test",
34.  
    schema = "test",
35.  
    superMapper = FreekaiMapper.class,
36.  
    desc = "userTest表的简单描述"
37.  
    )
38.  
    public class UserTestEntity extends RichEntity {
39.  
    private static final long serialVersionUID = 1L;
40.  
     
41.  
    @TableId(
42.  
    value = "id",
43.  
    auto = false
44.  
    )
45.  
    private Integer id;
46.  
     
47.  
    @TableField("address_id")
48.  
    private Integer addressId;
49.  
     
50.  
    @TableField("age")
51.  
    private Integer age;
52.  
     
53.  
    @TableField("create_time")
54.  
    private Date createTime;
55.  
     
56.  
    @TableField("tel")
57.  
    private String tel;
58.  
     
59.  
    @TableField("update_time")
60.  
    private Date updateTime;
61.  
     
62.  
    @TableField("user_name")
63.  
    private String userName;
64.  
     
65.  
    @TableField("version")
66.  
    private Integer version;
67.  
     
68.  
    @TableField(
69.  
    value = "is_delete",
70.  
    insert = "0",
71.  
    desc = "是否删除"
72.  
    )
73.  
    @LogicDelete
74.  
    private Boolean isDelete;
75.  
     
76.  
    @Override
77.  
    public final Class entityClass() {
78.  
    return UserTestEntity.class;
79.  
    }
80.  
     
81.  
    /**
82.  
    * @see com.freekai.fluent.IEntityRelation#findAddressV2OfUserTestEntity(java.util.List)
83.  
    */
84.  
    @RefMethod("userTestId = id")
85.  
    public UserTestAddressEntity findAddressV2() {
86.  
    return super.invoke("findAddressV2", true);
87.  
    }
88.  
    }

userTestAddress.java

1.  
   package com.freekai.fluent.entity;
2.  
    
3.  
   import cn.org.atool.fluent.mybatis.annotation.FluentMybatis;
4.  
   import cn.org.atool.fluent.mybatis.annotation.RefMethod;
5.  
   import cn.org.atool.fluent.mybatis.annotation.TableField;
6.  
   import cn.org.atool.fluent.mybatis.annotation.TableId;
7.  
   import cn.org.atool.fluent.mybatis.base.RichEntity;
8.  
   import com.freekai.custom.FreekaiMapper;
9.  
   import lombok.AllArgsConstructor;
10.  
    import lombok.Data;
11.  
    import lombok.EqualsAndHashCode;
12.  
    import lombok.NoArgsConstructor;
13.  
    import lombok.experimental.Accessors;
14.  
     
15.  
    /**
16.  
    * UserTestAddressEntity: 数据映射实体定义
17.  
    *
18.  
    * @author Powered By Fluent Mybatis
19.  
    */
20.  
    @SuppressWarnings({"rawtypes", "unchecked"})
21.  
    @Data
22.  
    @Accessors(
23.  
    chain = true
24.  
    )
25.  
    @EqualsAndHashCode(
26.  
    callSuper = false
27.  
    )
28.  
    @AllArgsConstructor
29.  
    @NoArgsConstructor
30.  
    @FluentMybatis(
31.  
    table = "user_test_address",
32.  
    schema = "test",
33.  
    superMapper = FreekaiMapper.class
34.  
    )
35.  
    public class UserTestAddressEntity extends RichEntity {
36.  
    private static final long serialVersionUID = 1L;
37.  
     
38.  
    @TableId(
39.  
    value = "id",
40.  
    auto = false
41.  
    )
42.  
    private Integer id;
43.  
     
44.  
    @TableField("address")
45.  
    private String address;
46.  
     
47.  
    @TableField("user_test_id")
48.  
    private Integer userTestId;
49.  
     
50.  
    @Override
51.  
    public final Class entityClass() {
52.  
    return UserTestAddressEntity.class;
53.  
    }
54.  
     
55.  
    /**
56.  
    * @see com.freekai.fluent.IEntityRelation#findUserTestV2OfUserTestAddressEntity(UserTestAddressEntity)
57.  
    */
58.  
    @RefMethod
59.  
    public UserTestEntity findUserTestV2() {
60.  
    return super.invoke("findUserTestV2", true);
61.  
    }
62.  
    }

 思考有个问题，如何像JPA一样根据主键 是否删除这个字段查询呢？ 实现是比较简单，那么是不是每个实体类都需要再写一遍很类似的代码呢？ ans:不需要。见下方

superMapper指定了自定义的一个类FreekaiMapper，这个类里，我自定义了一个根据主键 是否删除这个字段查询的方法。 相当于Jpa中 findByIdAndIsDelete(id, isDelete)..., FreekaiMapper.class内容如下

1.  
   package com.freekai.custom;
2.  
    
3.  
   import cn.org.atool.fluent.mybatis.If;
4.  
   import cn.org.atool.fluent.mybatis.base.IEntity;
5.  
   import cn.org.atool.fluent.mybatis.base.crud.IQuery;
6.  
   import cn.org.atool.fluent.mybatis.base.crud.IWrapper;
7.  
   import cn.org.atool.fluent.mybatis.base.entity.IMapping;
8.  
   import cn.org.atool.fluent.mybatis.base.free.FreeQuery;
9.  
   import cn.org.atool.fluent.mybatis.base.mapper.IEntityMapper;
10.  
    import cn.org.atool.fluent.mybatis.base.mapper.IMapper;
11.  
    import cn.org.atool.fluent.mybatis.base.mapper.IRichMapper;
12.  
    import cn.org.atool.fluent.mybatis.base.model.SqlOp;
13.  
    import cn.org.atool.fluent.mybatis.base.provider.SqlKitFactory;
14.  
    import cn.org.atool.fluent.mybatis.exception.FluentMybatisException;
15.  
    import cn.org.atool.fluent.mybatis.segment.WhereBase;
16.  
    import cn.org.atool.fluent.mybatis.segment.model.WrapperData;
17.  
    import org.apache.ibatis.annotations.Mapper;
18.  
    import org.springframework.stereotype.Component;
19.  
    import org.springframework.util.StringUtils;
20.  
     
21.  
    import java.util.List;
22.  
     
23.  
    /**
24.  
    * 自定义mapper，在代码生成时 配置一个supperMapper
25.  
    * 或者是在entity实体类上的@FluentMybatis注解中配置superMapper值
26.  
    * @FluentMybatis(
27.  
    * table = "user_test",
28.  
    * schema = "test",
29.  
    * superMapper = FreekaiMapper.class
30.  
    * )
31.  
    *
32.  
    *
33.  
    * @param <E>
34.  
    */
35.  
    public interface FreekaiMapper<E extends IEntity> extends IEntityMapper<E>, IRichMapper<E> {
36.  
     
37.  
    default E findByIdAndIsDelete(Object id, Boolean isDelete) {
38.  
    final IMapping mapping = this.mapping();
39.  
    IQuery query = mapping.emptyQuery();
40.  
    String primary = mapping.primaryId(true);
41.  
    // 逻辑删除的字段
42.  
    final String loginDeleteColumn = mapping.logicDeleteColumn();
43.  
    final WhereBase apply = query.where().apply(primary, SqlOp.EQ, new Object[]{id});
44.  
    if(!StringUtils.isEmpty(loginDeleteColumn)){
45.  
    apply.and.apply(loginDeleteColumn, SqlOp.EQ, isDelete);
46.  
    }
47.  
    final List<E> list = this.listEntity(query);
48.  
    if (If.isEmpty(list)) {
49.  
    return null;
50.  
    } else if (list.size() == 1) {
51.  
    return list.get(0);
52.  
    } else {
53.  
    throw new FluentMybatisException("Expected one result (or null) to be returned, but found " list.size() " results.");
54.  
    }
55.  
    }
56.  
    }

其中fluent-mybatis语法可以去官方查看对应的文档。下面一个controller是自己随便写的一些，完整的项目代码在github上。 https://github.com/freekai777/freekai-fluent-mybatis-demohttps://github.com/freekai777/freekai-fluent-mybatis-demo

1.  
   package com.freekai.controller;
2.  
    
3.  
   import cn.org.atool.fluent.mybatis.base.free.FreeQuery;
4.  
   import cn.org.atool.fluent.mybatis.base.model.FieldMapping;
5.  
   import cn.org.atool.fluent.mybatis.model.StdPagedList;
6.  
   import com.freekai.dto.SimpleUserTestDTO;
7.  
   import com.freekai.entity.HelloFluentEntity;
8.  
   //import com.freekai.mapper.HelloFluentMapper;
9.  
   import com.freekai.fluent.entity.UserTestEntity;
10.  
    import com.freekai.fluent.mapper.UserTestMapper;
11.  
    import com.freekai.fluent.wrapper.UserTestQuery;
12.  
    import com.freekai.mapper.HelloFluentMapper;
13.  
    import org.springframework.beans.factory.annotation.Autowired;
14.  
    import org.springframework.util.StringUtils;
15.  
    import org.springframework.web.bind.annotation.*;
16.  
     
17.  
    import java.util.HashMap;
18.  
    import java.util.List;
19.  
    import java.util.Map;
20.  
    import java.util.Random;
21.  
     
22.  
    @RestController
23.  
    public class HelloFluentMybatisController {
24.  
     
25.  
    @Autowired
26.  
    private UserTestMapper userTestMapper;
27.  
     
28.  
    @PostMapping("/addHello")
29.  
    public int addHello(){
30.  
    UserTestEntity entity = new UserTestEntity();
31.  
    entity.setId(1000*new Random().nextInt(10) 1);
32.  
    final int insert = userTestMapper.insertWithPk(entity);
33.  
    return insert;
34.  
    }
35.  
     
36.  
    @PutMapping("/updateUser")
37.  
    public int updateUser(@RequestParam String id){
38.  
    final UserTestEntity byIdAndIsDelete = userTestMapper.findByIdAndIsDelete(id, false);
39.  
    return 1;
40.  
    }
41.  
     
42.  
    @GetMapping("/user")
43.  
    public UserTestEntity get(@RequestParam Integer userId ){
44.  
    final UserTestEntity byId = userTestMapper.findById(userId);
45.  
    return byId;
46.  
    }
47.  
     
48.  
    /**
49.  
    * 聚合的语法
50.  
    * @return
51.  
    */
52.  
    @GetMapping("/agg")
53.  
    public List<Map<String,Object>> aggregation(){
54.  
    final List<Map<String, Object>> maps = userTestMapper.listMaps(userTestMapper.query().select.userName("userNameAlias")
55.  
    .count("cc").end().groupBy.userName().end().orderBy.desc("cc").end());
56.  
    return maps;
57.  
    }
58.  
     
59.  
    /**
60.  
    * 分页查询
61.  
    * @param userName
62.  
    * @param page
63.  
    * @param size
64.  
    * @return
65.  
    */
66.  
    @GetMapping("/users")
67.  
    public StdPagedList<UserTestEntity> list(@RequestParam(required = false, value = "userName") String userName,
68.  
    @RequestParam(value = "page", defaultValue = "1",required = false) Integer page,
69.  
    @RequestParam(value = "size", defaultValue = "10",required = false) Integer size){
70.  
    final StdPagedList<UserTestEntity> res = userTestMapper.stdPagedEntity(new UserTestQuery().where.userName()
71.  
    .like(userName, !StringUtils.isEmpty(userName)).end().limit((page - 1) * size, size));
72.  
    return res;
73.  
    }
74.  
     
75.  
    /**
76.  
    * 分页且映射成自定义实体类的查询
77.  
    *
78.  
    * 查询出来的 字段取的别名一定要求在 映射的实体类中存在。否则会报错！！
79.  
    *
80.  
    */
81.  
    @GetMapping("/users2")
82.  
    public StdPagedList<SimpleUserTestDTO> listWithDtos(@RequestParam(required = false, value = "userName") String userName,
83.  
    @RequestParam(value = "page", defaultValue = "1",required = false) Integer page,
84.  
    @RequestParam(value = "size", defaultValue = "10",required = false) Integer size){
85.  
    final StdPagedList<SimpleUserTestDTO> res = userTestMapper.stdPagedPoJo(SimpleUserTestDTO.class, new UserTestQuery()
86.  
    .select.id("idNew").createTime("createTime").end().where.userName()
87.  
    .like(userName, !StringUtils.isEmpty(userName)).end().limit((page - 1) * size, size));
88.  
    return res;
89.  
    }
90.  
     
91.  
    /**
92.  
    * 自定义sql查询
93.  
    * 通过占位符的形式 username
94.  
    * @return
95.  
    */
96.  
    @GetMapping("/custom_sql")
97.  
    public List<Map<String,Object>> customQuery(@RequestParam String userName){
98.  
    Map<String,String> param = new HashMap<>(16);
99.  
    param.put("userNN", userName "%");
100.  
      
101.  
     final FreeQuery freeQuery = new FreeQuery(null).customizedByPlaceholder(" select * from user_test t where t.user_name like #{userNN} ", param);
102.  
     final List<Map<String, Object>> maps = userTestMapper.listMaps(freeQuery);
103.  
     return maps;
104.  
     }
105.  
     }

另外也有一种，甚至连实现都不用写的，直接用Jpa的写法。需要在类上加注解

@FormService(table = "user_test")

，然后在启动类上配置扫描路径

@SpringBootApplication
@MapperScan({"com.freekai.mapper","com.freekai.fluent"})
@FormServiceScan("com.freekai.controller")
public class FluentMybatisApplication {...}

1.  
   @RestController
2.  
   @FormService(table = "user_test")
3.  
   public interface HelloFluentRestApi {
4.  
    
5.  
   @GetMapping("/findByUserName")
6.  
   UserTestEntity findByUserName(@RequestParam("userName") @Entry(value = "userName") String userName);
7.  
   }

通过postMan调用，发现也可以出现正确的结果。

这篇好文章是转载于：学新通技术网