SpringBoot整合MyBatis-plus

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。

[code]<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

[code]<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。

[code]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

[code]@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

[code]@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;
}

[code]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;
}
}

[code]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

[code]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）

[code]@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;
}