springboot_3（task、mybatis注解开发、mybatis-plus）

文章目录

定时任务

玩转SpringBoot之定时任务详解（定时表达式持久化、多线程执行定时任务）

springboot内部集成，不需要引入jar包，不需要配置。
定时任务使用务必存进redis或mysql，以防服务器挂掉定时任务丢失。
使用（基本同spring）：
在Application.java添加注解

@EnableScheduling

编写定时任务

@Component
public class ScheduleService {

    @Scheduled(cron = "*/5 15 18 * * ?")
    public void scheduledTest(){
        System.out.println("定时任务");
    }

}

mybatis基于注解开发

使用注解开发不需要xml文件，所以pom文件的resources不必再配置，yml文件的mapper-locations也不用再配置。别名和驼峰映射也不需要。
mapper接口代码

public interface ApplySimpleMapper {

    @Delete("delete from aftersale_return_apply_simple where aras_id = #{arasId}")
    int deleteByPrimaryKey(Integer arasId);

    @Insert("<script>" +
            "insert into aftersale_return_apply_simple" +
            "<trim prefix='(' suffix=')' suffixOverrides=','>" +
            "<if test='arasName != null'>aras_name,</if>" +
            "<if test='arasOrderId != null'>aras_order_id,</if>" +
            "</trim>" +
            "<trim prefix='values (' suffix=')' suffixOverrides=','>" +
            "<if test='arasName != null'>#{arasName},</if>" +
            "<if test='arasOrderId != null'>#{arasOrderId},</if>" +
            "</trim>" +
            "</script>")
    @Options(useGeneratedKeys = true, keyProperty = "arasId")
    int insertSelective(ApplySimple record);


    @Select("select * from aftersale_return_apply_simple where aras_id = #{arasId}")
    ApplySimple selectByPrimaryKey(Integer arasId);


    @Select("<script>" +
            "select * from aftersale_return_apply_simple" +
            "<where>" +
            "<if test='arasName != null'>and aras_name = #{arasName}</if>" +
            "<if test='arasOrderId != null'>and aras_order_id = #{arasOrderId}</if>" +
            "</where>" +
            "</script>")
    List<ApplySimple> selectByPrimaryKeyList(ApplySimple applySimple);


    @Update("<script>update aftersale_return_apply_simple" +
            "<set >" +
            "<if test='arasName != null'>aras_name = #{arasName},</if>" +
            "<if test='arasOrderId != null'>aras_order_id = #{arasOrderId},</if>" +
            "<if test='arasRecordName != null'>aras_record_name = #{arasRecordName},</if>" +
            "<if test='arasStatus != null'>aras_status = #{arasStatus},</if>" +
            "<if test='arasCreatetime != null'>aras_createtime = #{arasCreatetime},</if>" +
            "<if test='arasUpdatetime != null'>aras_updatetime = #{arasUpdatetime},</if>" +
            "</set>" +
            "where aras_id = #{arasId}" +
            "</script>")
    int updateByPrimaryKeySelective(ApplySimple record);

}

mybatis-plus

MyBatis-Plus官方文档

引入mybatis-plus的pom，基于mybatis，所以不需要重复引入mybatis的pom。
与pagehelper包冲突，排出冲突的jar包（pagehelper不需要就删掉）

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.0</version>
</dependency>

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.2.13</version>
    <exclusions>
        <exclusion>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
        </exclusion>
        <exclusion>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Application.java配置MapperScan

@MapperScan("com.javasm.mapper")
@EnableTransactionManagement

配置datasource

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://192.168.14.241:3306/crm?characterEncoding=UTF8&useSSL=true&serverTimezone=Asia/Shanghai
    username: root
    password: root

实体类用到的注解

@TableName("test_mybatisplus")
public class TestMybatisplus {

	  @TableId(type = IdType.ASSIGN_ID) // 分布式唯一id，雪花算法
	  private Long tid;
	  private String tname;
	  private String tadd;
	  private String tcreatetime;
	  private String tupdatetime;
	
	  @TableField(exist = false) // 非数据库字段
	  private String authControl;
	
	  @Version  // 乐观锁注解
	  private Integer tversion;
  }

crud测试

@SpringBootTest
public class MyBatisPlusTest {
    @Resource
    private ApplySimpleMapper2 sm;

    @Test
    public void add(){
        TestMybatisplus mp = new TestMybatisplus();
        mp.setTname("测试");
        int insert = sm.insert(mp);
        // mybatisplus会自动把当前插入对象在数据库中的id写回到该实体中
        System.out.println(mp.getTid());
    }
    @Test
    public void update(){
        TestMybatisplus mp = new TestMybatisplus();
        mp.setTid(123L);
        mp.setTname("测试9");
        // 乐观锁插件配置之后，更新成功version会自增加一，version不一致更新返回值为0
        mp.setTversion(1);
        //根据id进行更新，没有传值的属性就不会更新
        int i = sm.updateById(mp);

        System.out.println(i);

    }
    @Test
    public void select(){
        // 条件构造器
        QueryWrapper wrapper = new QueryWrapper();
        wrapper.between("tcreatetime","2020-08-20","2020-09-20");
        wrapper.like("tname","测试");
        List<TestMybatisplus> testMybatispluses = sm.selectList(wrapper);

//        Map<String, Object> map = new HashMap<>();
//        map.put("tname","测试4");
//        List<TestMybatisplus> testMybatispluses = sm.selectByMap(map);

        System.out.println(testMybatispluses);
    }

}

自定义配置类，配置分页插件及乐观锁插件

@Configuration
public class MyConfiguration {
    //Jackson中通过ObejctMapper对象的writeValueAsString
    // 由于分布式id过长，js会精度损失，将id转为string再序列化
    @Bean
    ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
        ObjectMapper build = builder.createXmlMapper(false).build();
        build.setSerializationInclusion(JsonInclude.Include.NON_NULL);//非空才序列化
        SimpleModule module = new SimpleModule();
        module.addSerializer(Long.class,ToStringSerializer.instance);
        module.addSerializer(long.class,ToStringSerializer.instance);
        build.registerModule(module);
        return build;
    }

    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        //分页拦截器
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        //乐观锁拦截器
        interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
        return interceptor;
    }
}

逆向工程

pom引入，使用freemarker模板引擎

<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-generator</artifactId>
	<version>3.4.0</version>
</dependency>
	
<dependency>
	<groupId>org.freemarker</groupId>
	<artifactId>freemarker</artifactId>
	<version>2.3.30</version>
</dependency>

生成代码使用官网模板，稍作修改即可。

分页插件使用

@RestController
@RequestMapping("/generator")
public class TestMybatisplusController {

    @Resource
    private ITestMybatisplusService ms;

    @GetMapping("mp")
    public ResponseEntity getmp(@RequestParam(defaultValue = "1") Integer pageNum, @RequestParam(defaultValue = "2")Integer pageSize){
        IPage<MP> page = new Page<>(pageNum,pageSize);
        IPage<MP> page1 = ms.page(page);
        return ResponseEntity.ok(page1);
    }
}

原文链接：https://blog.csdn.net/qq_43050847/article/details/108328954