原创作品，可以转载，但是请标注出处地址：https://www.cnblogs.com/V1haoge/p/10125279.html
SpringBoot整合MyBatis-plus 步骤 第一步：添加必要的依赖第一种是在已存在MyBatis的情况下，直接添加mybatis-plus包即可。
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus</artifactId> <version>2.1.8</version> </dependency>第二种是直接添加mybatis-plus的starter，它会自动导入mybatis的依赖包及其他相关依赖包
<dependency> <groupId>com.baomidou</groupId> <artifactId>mybatis-plus-boot-starter</artifactId> <version>3.0.1</version> </dependency> 第二步：添加必要的配置注意：Mybatis-plus是MyBatis的再封装，添加MyBatis-plus之后我们的设置针对的应该是MyBatis-plus，而不是MyBatis。
mybatis-plus: mapper-locations: classpath*:/mapper/*.xml type-aliases-package: com.example.springbootdemo.entity type-aliases-super-type: java.lang.Object type-handlers-package: com.example.springbootdemo.typeHandler type-enums-package: com.example.springbootdemo.enums 第三步：添加必要的配置类 @EnableTransactionManagement @Configuration @MapperScan("com.example.springbootdemo.plusmapper") public class MyBatisPlusConfig { // mybatis-plus分页插件 @Bean public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); } } 第四步：定义实体 @Data @Builder @ToString @EqualsAndHashCode @NoArgsConstructor @AllArgsConstructor @TableName(value = "ANIMAL") public class Animal { @TableId(value = "ID",type = IdType.AUTO) private Integer id; @TableField(value = "NAME",exist = true) private String name; @TableField(value = "TYPE",exist = true) private AnimalType type; @TableField(value = "SEX",exist = true) private AnimalSex sex; @TableField(value = "MASTER",exist = true) private String master; } public enum AnimalType implements IEnum { CAT("1","猫"),DOG("2","狗"),TIGER("3","虎"),MOUSE("4","鼠"),MONKEY("5","猴"),LOAN("6","狮"),OTHER("7","其他"); private final String value; private final String desc; AnimalType(final String value,final String desc){ this.value=value; this.desc = desc; } @Override public Serializable getValue() { return value; } public String getDesc() { return desc; } } public enum AnimalSex implements IEnum { MALE("1","公"),FEMALE("2","母"); private final String value; private final String desc; AnimalSex(final String value,final String desc){ this.value = value; this.desc = desc; } @Override public Serializable getValue() { return value; } public String getDesc() { return desc; } } 第五步：定义mapper接口 public interface AnimalRepository extends BaseMapper<Animal> { }解说：使用MyBatis Plus后Mapper只要继承BaseMapper接口即可，即使不添加XML映射文件也可以实现该接口提供的增删改查功能，还可以配合Wrapper进行条件操作，当然这些操作都仅仅限于单表操作，一旦涉及多表联查，那么还是乖乖添加**Mapper.xml来自定义SQL吧！！！
第六步：定义service（重点） @Service @Log4j2 public class AnimalService { @Autowired private AnimalRepository animalRepository; //增 public ResponseEntity<Animal> addAnimal(final Animal animal) { animalRepository.insert(animal); return ResponseEntity.ok(animal); } //删 public ResponseEntity<Integer> deleteAnimalById(final int id){ return ResponseEntity.ok(animalRepository.deleteById(id)); } public ResponseEntity<Integer> deleteAnimals(final Animal animal){ return ResponseEntity.ok(animalRepository.delete(packWrapper(animal, WrapperType.QUERY))); } public ResponseEntity<Integer> deleteAnimalsByIds(List<Integer> ids){ return ResponseEntity.ok(animalRepository.deleteBatchIds(ids)); } public ResponseEntity<Integer> deleteAnimalsByMap(final Animal animal){ Map<String, Object> params = new HashMap<>(); if(Objects.nonNull(animal.getId())){ params.put("ID",animal.getId()); } if(StringUtils.isNotEmpty(animal.getName())){ params.put("NAME", animal.getName()); } if(Objects.nonNull(animal.getType())){ params.put("TYPE", animal.getType()); } if(Objects.nonNull(animal.getSex())){ params.put("SEX", animal.getSex()); } if (StringUtils.isNotEmpty(animal.getMaster())){ params.put("MASTER", animal.getMaster()); } return ResponseEntity.ok(animalRepository.deleteByMap(params)); } //改 public ResponseEntity<Integer> updateAnimals(final Animal animal, final Animal condition){ return ResponseEntity.ok(animalRepository.update(animal, packWrapper(condition, WrapperType.UPDATE))); } public ResponseEntity<Integer> updateAnimal(final Animal animal){ Wrapper<Animal> animalWrapper = new UpdateWrapper<>(); ((UpdateWrapper<Animal>) animalWrapper).eq("id",animal.getId()); return ResponseEntity.ok(animalRepository.update(animal, animalWrapper)); } //查 public ResponseEntity<Animal> getAnimalById(final int id){ return ResponseEntity.ok(animalRepository.selectById(id)); } public ResponseEntity<Animal> getOneAnimal(final Animal animal){ return ResponseEntity.ok(animalRepository.selectOne(packWrapper(animal, WrapperType.QUERY))); } public ResponseEntity<List<Animal>> getAnimals(final Animal animal){ return ResponseEntity.ok(animalRepository.selectList(packWrapper(animal, WrapperType.QUERY))); } public ResponseEntity<List<Animal>> getAnimalsByIds(List<Integer> ids){ return ResponseEntity.ok(animalRepository.selectBatchIds(ids)); } public ResponseEntity<List<Animal>> getAnimalsByMap(final Animal animal){ Map<String, Object> params = new HashMap<>(); if(Objects.nonNull(animal.getId())){ params.put("ID",animal.getId()); } if(StringUtils.isNotEmpty(animal.getName())){ params.put("NAME", animal.getName()); } if(Objects.nonNull(animal.getType())){ params.put("TYPE", animal.getType()); } if(Objects.nonNull(animal.getSex())){ params.put("SEX", animal.getSex()); } if (StringUtils.isNotEmpty(animal.getMaster())){ params.put("MASTER", animal.getMaster()); } return ResponseEntity.ok(animalRepository.selectByMap(params)); } public ResponseEntity<List<Map<String, Object>>> getAnimalMaps(final Animal animal){ return ResponseEntity.ok(animalRepository.selectMaps(packWrapper(animal, WrapperType.QUERY))); } //查个数 public ResponseEntity<Integer> getCount(final Animal animal){ return ResponseEntity.ok(animalRepository.selectCount(packWrapper(animal, WrapperType.QUERY))); } //分页查询 public ResponseEntity<Page<Animal>> getAnimalPage(final Animal animal,final int pageId,final int pageSize){ Page<Animal> page = new Page<>(); page.setCurrent(pageId); page.setSize(pageSize); return ResponseEntity.ok((Page<Animal>) animalRepository.selectPage(page,packWrapper(animal, WrapperType.QUERY))); } private Wrapper<Animal> packWrapper(final Animal animal, WrapperType wrapperType){ switch (wrapperType){ case QUERY: QueryWrapper<Animal> wrapper = new QueryWrapper<>(); if (Objects.nonNull(animal.getId())) wrapper.eq("ID", animal.getId()); if (StringUtils.isNotEmpty(animal.getName())) wrapper.eq("name", animal.getName()); if (Objects.nonNull(animal.getType())) wrapper.eq("type", animal.getType()); if (Objects.nonNull(animal.getSex())) wrapper.eq("sex", animal.getSex()); if (StringUtils.isNotEmpty(animal.getMaster())) wrapper.eq("master", animal.getMaster()); return wrapper; case UPDATE: UpdateWrapper<Animal> wrapper2 = new UpdateWrapper<>(); if (Objects.nonNull(animal.getId())) wrapper2.eq("ID", animal.getId()); if (StringUtils.isNotEmpty(animal.getName())) wrapper2.eq("name", animal.getName()); if (Objects.nonNull(animal.getType())) wrapper2.eq("type", animal.getType()); if (Objects.nonNull(animal.getSex())) wrapper2.eq("sex", animal.getSex()); if (StringUtils.isNotEmpty(animal.getMaster())) wrapper2.eq("master", animal.getMaster()); return wrapper2; case QUERYLAMBDA: LambdaQueryWrapper<Animal> wrapper3 = new QueryWrapper<Animal>().lambda(); if (Objects.nonNull(animal.getId())) wrapper3.eq(Animal::getId, animal.getId()); if (StringUtils.isNotEmpty(animal.getName())) wrapper3.eq(Animal::getName, animal.getName()); if (Objects.nonNull(animal.getType())) wrapper3.eq(Animal::getType, animal.getType()); if (Objects.nonNull(animal.getSex())) wrapper3.eq(Animal::getSex, animal.getSex()); if (StringUtils.isNotEmpty(animal.getMaster())) wrapper3.eq(Animal::getMaster, animal.getMaster()); return wrapper3; case UPDATELAMBDA: LambdaUpdateWrapper<Animal> wrapper4 = new UpdateWrapper<Animal>().lambda(); if (Objects.nonNull(animal.getId())) wrapper4.eq(Animal::getId, animal.getId()); if (StringUtils.isNotEmpty(animal.getName())) wrapper4.eq(Animal::getName, animal.getName()); if (Objects.nonNull(animal.getType())) wrapper4.eq(Animal::getType, animal.getType()); if (Objects.nonNull(animal.getSex())) wrapper4.eq(Animal::getSex, animal.getSex()); if (StringUtils.isNotEmpty(animal.getMaster())) wrapper4.eq(Animal::getMaster, animal.getMaster()); return wrapper4; default:return null; } } } enum WrapperType{ UPDATE,UPDATELAMBDA,QUERY,QUERYLAMBDA; } 第七步：定义controller @RestController @RequestMapping("animal") @Api(description = "动物接口") @Log4j2 public class AnimalApi { @Autowired private AnimalService animalService; @RequestMapping(value = "addAnimal",method = RequestMethod.PUT) @ApiOperation(value = "添加动物",notes = "添加动物",httpMethod = "PUT") public ResponseEntity<Animal> addAnimal(final Animal animal){ return animalService.addAnimal(animal); } @RequestMapping(value = "deleteAnimalById", method = RequestMethod.DELETE) @ApiOperation(value = "删除一个动物",notes = "根据ID删除动物",httpMethod = "DELETE") public ResponseEntity<Integer> deleteAnimalById(final int id){ return animalService.deleteAnimalById(id); } @RequestMapping(value = "deleteAnimalsByIds",method = RequestMethod.DELETE) @ApiOperation(value = "删除多个动物",notes = "根据Id删除多个动物",httpMethod = "DELETE") public ResponseEntity<Integer> deleteAnimalsByIds(Integer[] ids){ return animalService.deleteAnimalsByIds(Arrays.asList(ids)); } @RequestMapping(value = "deleteAnimals", method = RequestMethod.DELETE) @ApiOperation(value = "删除动物",notes = "根据条件删除动物",httpMethod = "DELETE") public ResponseEntity<Integer> deleteAnimalsByMaps(final Animal animal){ return animalService.deleteAnimalsByMap(animal); } @RequestMapping(value = "deleteAnimals2", method = RequestMethod.DELETE) @ApiOperation(value = "删除动物",notes = "根据条件删除动物",httpMethod = "DELETE") public ResponseEntity<Integer> deleteAnimals(final Animal animal){ return animalService.deleteAnimals(animal); } @RequestMapping(value = "getAnimalById",method = RequestMethod.GET) @ApiOperation(value = "获取一个动物",notes = "根据ID获取一个动物",httpMethod = "GET") public ResponseEntity<Animal> getAnimalById(final int id){ return animalService.getAnimalById(id); } // 注意，这里参数animal不能用RequstBody标注，否则接收不到参数 // @RequestBody只能用在只有一个参数模型的方法中，用于将所有请求体中携带的参数全部映射到这个请求参数模型中 @RequestMapping(value = "getAnimalsByPage") @ApiOperation(value = "分页获取动物们",notes = "分页获取所有动物", httpMethod = "GET") public ResponseEntity<Page<Animal>> getAnimalsByPage(@RequestParam final int pageId, @RequestParam final int pageSize, final Animal animal) { return animalService.getAnimalPage(animal==null?Animal.builder().build():animal, pageId, pageSize); } @RequestMapping(value = "updateAnimal") @ApiOperation(value = "更新动物", notes = "根据条件更新",httpMethod = "POST") public ResponseEntity<Integer> updateAnimals(final Animal animal){ return animalService.updateAnimal(animal); } } 高级功能 代码生成器 分页插件 第一步：添加必要的配置 @EnableTransactionManagement @Configuration @MapperScan("com.example.springbootdemo.plusmapper") public class MyBatisPlusConfig { @Bean // mybatis-plus分页插件 public PaginationInterceptor paginationInterceptor() { return new PaginationInterceptor(); } } 第二步：添加Mapper public interface AnimalRepository extends BaseMapper<Animal> { } 第三步：添加service @Service @Log4j2 public class AnimalService { @Autowired private AnimalRepository animalRepository; //... public Page<Animal> getAnimalsByPage(int pageId,int pageSize) { Page page = new Page(pageId, pageSize); return (Page<Animal>)animalRepository.selectPage(page,null); } } 逻辑删除 所谓逻辑删除是相对于物理删除而言的，MyBatis Plus默认的删除操作是物理删除，即直接调用数据库的delete操作，直接将数据从数据库删除，但是，一般情况下，我们在项目中不会直接操作delete，为了保留记录，我们只是将其标记为删除，并不是真的删除，也就是需要逻辑删除，MyBatis Plus也提供了实现逻辑删除的功能，通过这种方式可以将底层的delete操作修改成update操作。 第一步：添加必要的配置 mybatis-plus: global-config: db-config: logic-delete-value: 1 # 逻辑已删除值(默认为 1) logic-not-delete-value: 0 # 逻辑未删除值(默认为 0) 第二步：添加必要的配置类 @Configuration public class MyBatisPlusConfiguration { @Bean public ISqlInjector sqlInjector() { return new LogicSqlInjector(); } } 第三步：添加字段isDel和注解 @TableLogic private Integer isDel; 如此一来，我们再执行delete相关操作的时候，底层就会变更为update操作，将isDel值修改为1。