MyBatisPlus#

1
<?xml version="1.0" encoding="UTF-8"?>
2
<project xmlns="http://maven.apache.org/POM/4.0.0"
3
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
5
    <parent>
6
        <artifactId>spring-boot-starter-parent</artifactId>
7
        <groupId>org.springframework.boot</groupId>
8
        <version>2.3.4.RELEASE</version>
9
    </parent>
10
    <modelVersion>4.0.0</modelVersion>
11
    <groupId>org.example</groupId>
12
    <artifactId>mybatis-plusDemo</artifactId>
13
    <version>1.0-SNAPSHOT</version>
14

15
    <dependencies>
16
        <dependency>
17
            <groupId>mysql</groupId>
18
            <artifactId>mysql-connector-java</artifactId>
19
            <version>5.1.47</version>
20
            <scope>runtime</scope>
21
        </dependency>
22
        <dependency>
23
            <groupId>org.springframework.boot</groupId>
24
            <artifactId>spring-boot-starter</artifactId>
25
        </dependency>
26
        <dependency>
27
            <groupId>org.springframework.boot</groupId>
28
            <artifactId>spring-boot-starter-test</artifactId>
29
            <scope>test</scope>
30
        </dependency>
31
        <dependency>
32
            <groupId>org.projectlombok</groupId>
33
            <artifactId>lombok</artifactId>
34
            <optional>true</optional>
35
        </dependency>
36
        <dependency>
37
            <groupId>com.baomidou</groupId>
38
            <artifactId>mybatis-plus-boot-starter</artifactId>
39
            <version>3.4.2</version>
40
        </dependency>
41

42

43

44
    </dependencies>
45

46

47

48
</project>

1
spring:
2
  datasource:
3
    url: jdbc:mysql://localhost:3306/mybatis-plus-demo
4
    username: root
5
    password: 123456
6
    driver-class-name: com.mysql.jdbc.Driver

1
package com.xiaodidi.mapper;
2

3
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
4
import com.xiaodidi.demo.User;
5
import org.apache.ibatis.annotations.Mapper;
6

7

8
public interface UserMapper extends BaseMapper<User> {
9

10
}

1
package com.xiaodidi;
2

3
import org.mybatis.spring.annotation.MapperScan;
4
import org.mybatis.spring.annotation.MapperScans;
5
import org.springframework.boot.SpringApplication;
6
import org.springframework.boot.autoconfigure.SpringBootApplication;
7

8
@SpringBootApplication
9
@MapperScan("com.xiaodidi.mapper")
10
public class MainApplication {
11
    public static void main(String[] args) {
12
        SpringApplication.run(MainApplication.class, args);
13

14
    }
15

16

17
}

1
package com.xiaodidi;
2

3
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
4
import com.xiaodidi.demo.User;
5
import com.xiaodidi.mapper.UserMapper;
6
import org.junit.Test;
7
import org.junit.runner.RunWith;
8
import org.springframework.beans.factory.annotation.Autowired;
9
import org.springframework.boot.test.context.SpringBootTest;
10
import org.springframework.test.context.junit4.SpringRunner;
11

12
import javax.annotation.Resource;
13
import java.util.List;
14
@RunWith(SpringRunner.class)
15
@SpringBootTest
16
public class TestDemo {
17
    @Resource
18
    UserMapper userMapper;
19
    @Test
20
    public void save() {
21
        List<User> users = userMapper.selectList(null);
22
        for (User user : users) {
23
            System.out.println(user);
24
        }
25
    }
26
}

1
@TableField(fill = FieldFill.INSERT)
2
private Date createTime;
3

4
//更新时间
5
@TableField(fill = FieldFill.INSERT_UPDATE)
6
private Date updateTime;

1
package com.atguigu.boot.config;
2

3
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
4
import lombok.extern.slf4j.Slf4j;
5
import org.apache.ibatis.reflection.MetaObject;
6
import org.springframework.stereotype.Component;
7

8
import java.time.LocalDateTime;
9
import java.util.Date;
10

11
@Slf4j
12
@Component
13
public class MyMetaObjectHandler implements MetaObjectHandler {
14

15
    //插入时候的填充策略
16
    @Override
17
    public void insertFill(MetaObject metaObject) {
18
        log.info("start insert fill ....");  //日志
19
        //设置字段的值（String fieldName字段名,Object fieldVal要传递的值,MetaObject metaObject)
20
        this.fillStrategy(metaObject, "createTime", new Date());
21
        this.fillStrategy(metaObject, "updateTime", new Date());
22

23

24
        //this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, LocalDateTime.now()); // 起始版本 3.3.0(推荐使用)
25
       // this.fillStrategy(metaObject, "createTime", LocalDateTime.now()); // 也可以使用(3.3.0 该方法有bug请升级到之后的版本如`3.3.1.8-SNAPSHOT`)
26
        /* 上面选其一使用,下面的已过时(注意 strictInsertFill 有多个方法,详细查看源码) */
27
        //this.setFieldValByName("operator", "Jerry", metaObject);
28
        //this.setInsertFieldValByName("operator", "Jerry", metaObject);
29
    }
30

31
    //更新时间的填充策略
32
    @Override
33
    public void updateFill(MetaObject metaObject) {
34
        log.info("start update fill ....");
35
        this.fillStrategy(metaObject, "updateTime", new Date());
36

37

38
        //this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now()); // 起始版本 3.3.0(推荐使用)
39
       // this.fillStrategy(metaObject, "updateTime", LocalDateTime.now()); // 也可以使用(3.3.0 该方法有bug请升级到之后的版本如`3.3.1.8-SNAPSHOT`)
40
        /* 上面选其一使用,下面的已过时(注意 strictUpdateFill 有多个方法,详细查看源码) */
41
        //this.setFieldValByName("operator", "Tom", metaObject);
42
        //this.setUpdateFieldValByName("operator", "Tom", metaObject);
43
    }
44
}

1
@ResponseBody
2
@RequestMapping("/saveRole")
3
public String saveRole() {
4
    Role role = new Role();
5
    role.setName("小");
6
    roleService.save(role);
7
    return "成功";
8

9

10

11
}

1
@Test
2
public void queryTest() {
3
    QueryWrapper<User> userQueryWrapper = new QueryWrapper<>();
4
    //查询所有名字中存在o的，同时年龄在16到20中的，如果不写就不进行判断
5
    String likeName = "o";
6
    Integer maxAge = 20;
7
    Integer minAge = 16;
8
    //如果第一个参数返回的是true就加入，如果返回的false那么就不进行加入
9
    userQueryWrapper.like(StringUtils.isNotBlank(likeName), "name", likeName)
10
            .gt(minAge!=null,"age",minAge)
11
            .lt(maxAge!=null,"age",maxAge);
12
    for (User user : userMapper.selectList(userQueryWrapper)) {
13
        System.out.println(user);
14
    }
15

16
}

1
@Test
2
public void queryTest2() {
3
    QueryWrapper<User> userQueryWrapper = new QueryWrapper<>();
4
    //查润name中带o的，同时查找年龄大于16或者name=xiaodidi
5
    userQueryWrapper.like("name","o").and(userQueryWrapper1 -> userQueryWrapper1.gt("age",16).or().eq("name","xiaodidi"));
6
    List<User> users = userMapper.selectList(userQueryWrapper);
7
    for (User user : users) {
8
        System.out.println(user);
9
    }
10

11

12
}

1
@Test
2
public void queryTest2() throws IOException {
3
    LambdaQueryWrapper<User> userQueryWrapper = new LambdaQueryWrapper<>();
4
    //查润name中带o的，同时查找年龄大于16或者name=xiaodidi
5
    userQueryWrapper.like((User::getUsername), "o").and(userQueryWrapper1 -> userQueryWrapper1.gt(User::getAge,16).or().eq(User::getUsername,"xiaodidi"));
6
    List<User> users = userMapper.selectList(userQueryWrapper);
7
    for (User user : users) {
8
        System.out.println(user);
9
    }
10

11

12

13
}

1
package com.xiaodidi;
2

3

4
import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
5
import lombok.Data;
6
import net.minidev.json.JSONUtil;
7

8
import java.lang.invoke.SerializedLambda;
9
import java.lang.reflect.Method;
10

11
@Data
12
public class LambdaTest {
13

14
    private String fieldA;
15

16
    public static void main(String[] args) throws Exception {
17
        SerializedLambda serializedLambda = doSFunction(LambdaTest::getFieldA);
18
        System.out.println("方法名：" + serializedLambda.getImplMethodName());
19
        System.out.println("类名：" + serializedLambda.getImplClass());
20

21
    }
22
/*SerializedLambda对象了。 实际上序列化的对象是通过writeReplace方法产生的，那么我们要获取SerializedLambda对象没必要真的序列化和反序列化一遍。 反射调用writeReplace方法就可以了。*/
23
    private static <T, R> java.lang.invoke.SerializedLambda doSFunction(SFunction<T, R> func) throws Exception {
24
        // 直接调用writeReplace
25
        Method writeReplace = func.getClass().getDeclaredMethod("writeReplace");
26
        writeReplace.setAccessible(true);
27
       //反射调用
28
        Object sl = writeReplace.invoke(func);
29
        java.lang.invoke.SerializedLambda serializedLambda = (java.lang.invoke.SerializedLambda) sl;
30
        return serializedLambda;
31
    }
32
}

1
global-config:
2
  db-config:
3
    logic-delete-field: deleted
4
    logic-delete-value: 1
5
    logic-not-delete-value: 0

1
@TableLogic
2
private String deleted;